Sector ProjectMechanical-biological Waste TreatmentFinal Report

Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ ) GmbH

Division 44Environment & Infrastructure

Published by

Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbHDag-Hammarskjöld-Weg 1-565760 Eschborn / Germany

Desk OfficerElke Hüttner (GTZ, Division 44 - Environment & Infrastructure)

EditingGernod Dilewski (INFRASTRUKTUR & UMWELT, Darmstadt), Joachim Stretz (Berlin)

in cooperation withGabriele Janikowski (IKW Beratungsinstitut fürKommunalwirtschaft GmbH, Cologne),Dr. Dirk Maak (Wilhelm Faber GmbH, Alzey), Dr. Aber Mohamad (University of Kassel),Dr. Dieter Mutz (Basel University of Applied Sciences - FHBB), Bernhard Schenk (Berlin)

DesignChristopher Heck•eyes-luna Multimedia-Design •, D- 64291 Darmstadt

Printed byDigitaldruck Darmstadt GmbH & Co. KG

Eschborn 2003

1

CONTENT

This report presents the main activities and results of the sector project "Promotion of Mechanical-

biological Waste Treatment", which was conducted by Deutsche Gesellschaft für Technische

Zusammenarbeit (GTZ) GmbH on behalf of the Federal German Ministry for Economic Cooperation

and Development (BMZ) between 1998 and 2003. The focal areas of the sector project were a trio of

pilot projects in São Sebastião (Brazil), Phitsanulok (Thailand), and Al-Salamieh (Syria), in which

mechanical-biological waste treatment (MBWT) options were field-tested under the relevant local

boundary conditions. All three pilot projects yielded satisfactory results following appropriate adapta-

tion of the decomposition process. The specific costs of MBWT ranged between 11 and 15 Euro/Mg

in all three cases. However, these expenditures are at least partially compensated by the resultant

savings in landfilling.

Sector Project MBWT - Final Report

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1 Introduction and Rationale 8

2 Introduction to MBWT 10

2.1 Characterization of MBWT 10

2.2 Waste Treatment Processes 11

2.3 Integration of MBWT into Municipal Waste Management Schemes 12

2.4 Climatic Factors 13

3 MBWT Reference Material and Events 15

3.1 MBWT Decision-maker's Guide 15

3.2 Videos 15

3.3 Costing Model 16

3.4 Conferences and Seminars 16

4 MBWT Pilot Projects 18

4.1 Short Descriptions of the Projects 18

4.1.1 Pilot project in São Sebastião, Brazil 18

4.1.2 Pilot project in Phitsanulok, Thailand 19

4.1.3 Scale-model MBWT trial in Al-Salamieh, Syria 19

4.1.4 Other projects 21

4.2 Results and Experience Gathered from Pilot Projects 22

4.2.1 Project preparation 23

4.2.2 Monitoring programs 23

4.2.2.1 Basic principles 23

4.2.2.2 Implementation via pilot projects 24

4.2.3 IMBWT processes employed in the pilot projects 25

4.2.3.1 Technology selection criteria 26

4.2.3.2 The Al-Salamieh scale-model trial 27

4.2.3.3 The FABER-AMBRA® process in

São Sebastião and Phitsanulok 28

4.2.3.4 Evaluation of the technologies employed 30

4.2.4 Operation of an MBWT facility 31

4.2.4.1 MBWT personnel requirements 32

4.2.4.2 Training 32

4.2.4.3 Integration into the organizational structures 33

4.2.5 Chronology and results of aerobic decomposition 34

4.2.5.1 Time history of in-heap temperatures 34

4.2.5.2 Effects of rainy season on the temperature curve 36

4.2.5.3 Gas composition 37

4.2.5.4 Water content 40

4.2.5.5 Solids and eluate analyses 40

4.2.5.6 Results of composting trials in

Al-Salamieh, Syria 41

Table of contents

4.2.6 Emissions from MBWT 43

4.2.6.1 Basic principles 43

4.2.6.2 Odors 44

4.2.6.3 Hygiene 44

4.2.6.4 Process water 44

4.2.6.5 Methane emissions 48

4.2.7 Disposal of pretreated waste to the landfill 48

4.2.7.1 Fundamental considerations 48

4.2.7.2 Mass reduction determined in the pilot projects 51

4.2.7.3 Emplacement trials in the pilot projects 52

4.2.7.4 Landfill leachate in São Sebastião 54

4.2.8 Costs 54

4.2.8.1 Costing principles 54

4.2.8.2 Examples of costs incurred in the pilot projects 55

4.2.8.3 Effects of MBWT on the cost of waste dis-posal 60

4.2.9 Informal sector 61

5 Future Prospects of MBWT in Developing and Threshold Countries 64

5.1 Conclusions Drawn from the Pilot Projects 64

5.2 Comparison of Alternative Waste Disposal Concepts 66

5.3 Need for Further Study 67

6 Summary 69

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APPENDICES

Appendix 1 Characterization of the Pilot Projects

Appendix 2 List of Important Contacts

Appendix 3 Bibliography

LIST OF TABLES

Table 1: Differences between composting and MBWT 10

Table 2: Anthropogenic emissions of CO2, CH4, and N2O within the EU in 1994 [1] 14

Table 3: Proposed monitoring program for the pilot-scale field trial in Phitsanulok 24

Table 4: Personnel requirements for MBWT operations in São Sebastião

(throughput: 30,000 Mg/a) 32

Table 5: Backstopping work scope for Faber during the one-year imple-

mentation phase in São Sebastião 32

Table 6: Water content of waste inputs in the pilot projects 40

Table 7: Results of treated -waste analysis in São Sebastião 41

Table 8: Heavy-metal contents as a function of input material 42

Table 9: Quantity and quality of process water from biotreatment wind-

rows in the Al-Salamieh scale-model trial 45

Table 10: Mass reduction through biotreatment in the Al-Salamieh,

Syria, scale-model trials 51

Table 11: Comparison of specific costs in the pilot projects 58

LIST OF FIGURES

Figure 1: The "Alvarenga" garbage dump in Sao Paulo, and the "Billings"

drinking water impounding reservoir Source: GTZ Photo Archive 8

Figure 2: The operational sequence of mechanical-biological waste treatment 10

Figure 3: A natural-draft (convecting) biotreatment windrow as an exam-

ple of extensive aerobic decomposition 11

Figure 4: Schematic rendition of an intensive aerobic decomposition process 12

Figure 5: Residual-waste treatment options 13

Figure 6: At the entrepreneurs' forum on "Public Private Partnerships

(PPP) in the International Waste Sector", in Eschborn, Germany 17

Figure 7: Mechanical-biological waste treatment using the FABER-AMBRA®

process in São Sebastião 18

Figure 8: Mechanical-biological waste treatment using the FABER-AMBRA®

‘process in Phitsanulok 19

Figure 9: Composting windrow in Al-Salamieh, with cover and forced ventilation 20

Figure 10: Training for Recicladores at the scale-model MBWT facility in

Armenia, Colombia 22

Figure 11: A typical decomposition temperature curve 23

Figure 12: Temperature monitoring with a sampling gauge in Phitsanulok 25

Figure 13: Waste pickers at the Phitsanulok landfill 26

Figure 14: Compost heaps during the model experiment in Al-Salamieh 27

Figure 15: Homogenizing drum at work in Phitsanulok 28

Figure 16: Waste from Phitsanulok before and after homogenization 29

Figure 17: Piling the waste for biological treatment in Atlacomulco, Mexico 29

Figure 18: Training for technical personnel at the Phitsanulok landfill 32

Figure 19: Theoretically achievable and actual throughput at the MBWT

facility of the Phitsanulok pilot project 33

5

Sector Project MBWT - Final Report

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Figure 20: Time history of in-heap temperatures in the Al-Salamieh scale-model trial 35

Figure 21: Time history of in-heap temperatures in São Sebastião 35

Figure 22: Time history of temperatures in a FABER-AMBRA® heap

Exposed to heavy precipitation 36

Figure 23: Relationship between oxygen content and carbon dioxide concentration 37

Figure 24: Waterlogged base of a heap showing evidence of anaerobic decomposition 38

Figure 25: Results of gas monitoring at heaps C and D on

February 13, 2003, in Phitsanulok 39

Figure 26: Coconut-shell biofilter at the Phitsanulok MBWT facility 44

Figure 27: Test heap in São Sebastião 45

Figure 28: Cumulative curves showing the precipitation onto and the pro-

cess water volume emerging from the test heap in São Sebastião 46

Figure 29: Quality of process water from test heaps in Rio de Janeiro

and São Sebastião 47

Figure 30: Process water seeping out from the base of a heap in São Sebastião 47

Figure 31: Densities of compaction with and without pretreatment [6] 49

Figure 32: Emplacement of pretreated waste in São Sebastião 51

Figure 33: Mass reduction in the pilot phase of MBWT in Phitsanulok 51

Figure 34: Test-field dimensions for the commercial-scale compaction trial 52

Figure 35: Dry-season emplacement trial for pretreated waste at the

Phitsanulok landfill in Thailand 52

Figure 36: Comparison of in-heap densities and achieved landfill

compaction densities 53

Figure 37: Leachate burden at the MBWT landfill in São Sebastião 54

7

Figure 38: Comparison of pilot-project cost calculations (specific costs in EUR/Mg) 59

Figure 39: Comparison of specific landfilling costs in Phitsanulok with and

without MBWT (specific costs in EUR/Mg) 61

Figure 40: Informal-sector intervention in the flow of household waste 61

Figure 41: Members of the Ilhabela Cooperative at work sorting recyclables 62

Figure 42: Avenues of waste disposal in the member countries of the EU in 1999 [7] 66

Sector Project MBWT - Final Report

In many developing countries, shifting living

habits in conjunction with increasing urbaniza-

tion and industrialization are strongly influencing

the volumes and composition of waste inci-

dence. As waste volumes expand and contain

ever larger quantities of packaging material and

hazardous substances, traditional forms of

waste disposal reach their limits, and in many

places new waste-disposal strategies have to be

devised to protect human health and avert en-

vironmental pollution.

Recent years have seen much progress made in

the area of waste collection. In contrast, there

has been little good news about waste disposal

in developing and threshold countries. Most

waste is still being disposed of at uncontrolled

dumps (fly tips) where no special measures are

taken to prevent pollution. Emissions from such

dumps jeopardize the health of nearby resi-

dents, contaminate the surrounding soil, and

threaten groundwater resources.

Consequently, people have in recent years

begun to speak out against this kind of waste

disposal. Particularly in large cities, it is beco-

ming increasingly difficult to find and provide the

necessary deposition capacities. Even if more

waste can be avoided and recycled in the future,

landfills will still be needed in the years to come

to accommodate the remaining unrecyclable

waste.

The environmental burdens resulting from the

disposal of residual waste can be reduced most

effectively by intelligent selection of landfill loca-

tions, structural measures (e.g. liners) and opti-

mized modes of landfill operation. In addition,

waste can be pretreated to modify its properties

so that less pollution will result when it is dum-

ped. One means of pretreatment is to incinerate

the waste, although the resultant slag and the

residue from the off-gas scrubbing system still

have to be disposed of afterwards. In Europe,

recent years have seen the emergence of

mechanical-biological waste treatment (MBWT)

as an alternative, or complement, to waste inci-

neration. Germany is a global leader in the

design and use of MBWT technology.

Especially the organic fraction of municipal solid

waste (MSW) constitutes a serious environmen-

tal risk when dumped at landfills, because it will

subsequently undergo uncontrolled biological

decomposition. The basic idea of MBWT, there-

fore, is to pretreat such waste under controlled

conditions prior to its ultimate disposal in order

to optimize decomposition of the organic frac-

tion, hence reducing its pollution potential.

Mechanical-biological waste treatment can, sub-

ject to certain conditions, be significantly more

cost-effective than waste incineration and is

therefore viewed as an attractive alternative

technology. However, little experience has been

gained to date in the use of this technology in

developing and threshold countries.

1 Introduction and Rationale

8

Figure 1: The "Alvarenga" garbage dump in Sao Paulo, andthe "Billings" drinking water impounding reservoirSource: GTZ Photo Archive

9

Past attempts to transfer waste technologies

from industrialized countries of the West to

developing countries have led to numerous

disappointments. Hence it was not the sole

objective of the GTZ sector project "Promotion

of Mechanical-biological Waste Treatment" to

simply disseminate the technology, but also and

in particular to carry out a critical analysis of the

risks and potentials of MBWT. The pilot-scale

MBWT field tests conducted in various countries

provide the main basis for this analysis.

The sector project focused on both the technical

components and some key areas of develop-

ment policy, including in particular the living

conditions of waste pickers and how they would

be affected by the introduction of mechanical-

biological waste treatment.

The sector project "Promotion of Mechanical-

biological Waste Treatment" was designed for a

term of six years (1998 - 2003) and was finan-

ced by the Federal German Ministry for Econo-

mic Cooperation and Development (BMZ). Its

focal areas were:

generating and providing reference material

on MBWT,

conducting seminars and training events,

elaborating feasibility studies for MBWT

developing countries, including the explora-

tion of socioeconomic aspects,

planning and implementing exemplary pilot-

scale applications with scientific back-

stopping.

Numerous German and foreign partners were

attracted to the project to help implement its

activities:

Federal German Ministry of Education and

Research (BMBF)

Knoten Weimar

the Faber Group

the University of Kassel

Prefeitura São Sebastião

Prefeitura Municipal Ilhabela

Municipality of Phitsanulok

The individual project partners' names, addres-

ses and contact persons are listed in the

Appendix.

The primary goal of MBWT is to minimize

the environmental burdens of waste dis-

posal by way of extensive stabilization. MBWT

can also help to recover valuable materials (cf.

Chapter 2.3). The terms composting and MBWT

are often used together, because both approa-

ches rely on quite similar techniques. However,

the two processes do pursue different objectives

(cf. Table 1).

2.1 Characterization of MBWT

As shown in Figure 2, MBWT generally compri-

ses the following steps:

waste input and control,

mechanical conditioning,

biological treatment and

emplacement of treated waste at a landfill.

In the mechanical stage, the first step is to sort

out the disturbants (e.g. large pieces of metal),

unwanted materials and - optionally - recycla-

bles. Next, the residual waste is prepared for

biological treatment by comminution, mixing

and, if necessary, moistening. Then comes the

biological stage, the purpose of which is to

effect extensive biological stabilization of the

waste. There are two basic methods of biologi-

cal decomposition:

aerobic decomposition, i.e. decomposition

in the presence of atmospheric oxygen, and

anaerobic digestion, i.e. decomposition

the absence of atmospheric oxygen, also

referred to as fermenting.

The biological decomposition and conversion of

organic matter by microorganisms (bacterial,

protozoa, fungi) is a natural form of recycling

that takes place in landfilled waste. As biological

decomposition progresses in a landfill, anaer-

obic digestion generates a combustible, explosi-

ve gas referred to as sanitary landfill gas. This

gas escapes from the landfill and contributes to

global warming and hence to climate degra-

dation. Water seeping into the landfill, together

with water contained in the waste, becomes

contaminated by the products of decomposition

and by the leaching out of pollutants.

Sector Project MBWT - Final Report

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2 Introduction to MBWT

Process Main objective Input

Composting To obtain a high-quality,marketable soil conditio-ner (compost)

Defined inputs with decisiveinfluence on the quality ofthe product (e.g. separatelycollected biowaste)

MBWT To minimize, by means ofextensive stabilization, theenvironmental pollution re-sulting from waste dispo-sal

Mixed municipal solidwaste (MSW)

Tabelle 1: Differences between composting and MBWT

Iner

t fr

actio

ns

NonbiodegradablesRecyclablesHigh-Energy

Fraction

Waste input and control

Disposal to landfill

Mechanical conditioning

Coarse sorting ScreeningSorting CombinutionMagnetic Separation Homogenization

Biological treatment

Aerobic Anaerobic/AerobicDecomposition Ferm. + post-decomp.

Screening

Optional

Sew

age

slud

ge

Co

ver

Figure 2: The operational sequence of mechanical-biological waste treatment

To keep the leachate and the landfill gas from

escaping to the environment, the landfill needs

to be sealed so that they can be collected and

treated systematically.

Through the controlled decomposition of organic

substances, mechanical-biological waste treat-

ment substantially reduces both the gas and

water emissions which would otherwise be sub-

sequently generated at the landfill and the volu-

me of the residual waste requiring emplacement.

Waste containing a large share of biodegradable

organic material is most suitable for such treat-

ment. This is generally the case for household

and commercial waste. However, contaminated

waste, e.g. hazardous industrial waste; infec-

tious waste, e.g. waste from hospitals and

slaughterhouses; and constructionsite waste are

inherently unsuitable. The suitability of industrial

waste needs to be determined in advance, e.g.

by analyzing, on a case-by-case basis, its pollu-

tant concentrations and biomass fractions.

2.2 Waste Treatment Processes

There is a broad spectrum of equipment and

biological treatment methods that can be com-

bined for the purposes of mechanical-biological

waste treatment, depending on the local situa-

tion and the waste-management targets. For

example, some facilities are modestly equipped

and are operated using extensive-type proces-

ses, i.e. processes involving little automation

and low outlays for construction and process

control.

11

Ventilating pipes

Rows of pallets

~20 cm

~60 m

~2,5 m

Wind

Base ~25 m

BiofilterAtmospheric

pressure

Slope approx.ca. 3%

Fresh airExhaust air

Homogenized waste

Figure 3: A natural-draft (convecting) biotreatment windrow as an example of extensive aerobic decomposition

Conversely, depending on the set objectives of

treatment, the financial leeway, and various

other boundary conditions, biological treatment

can also be pursued using semiautomatic, tech-

nically optimized, indoor, emission-controlled

systems (intensive approach).

Intensive approaches help reduce the decompo-

sing time and the specific space requirements.

Closed systems (hall, container) allow emissions

(gas, odor, dust, ...) to be controlled. Also, the

decomposition process can be controlled and

optimized by way of active ventilation, moisturi-

zing and blending. This significantly accelerates

the main decomposition process and increases

the share of organic matter that actually decom-

poses. However, the structure and the requisite

equipment make this approach too expensive

for anything but large amounts of waste, and the

high degree of automation makes the system

more susceptible to disturbances and therefore

necessitates higher expenditures for maintenan-

ce and repair.

2.3 Integration of MBWT into Municipal

Waste Management Schemes

The first step toward determining the extent to

which MBWT may or may not constitute a good

approach to waste management for a given city

or region is to survey and analyze the existing

waste-management situation.

Prior to deciding in favor of mechanical-biologi-

cal waste treatment, other waste-treatment

alternatives should also be considered. In indu-

strialized countries, for example, waste incinera-

tion is a fairly popular form of residual-waste

treatment. The flue-gas emissions are of primary

interest when evaluating environmental pollution

from waste incineration plants (WIPs).

Sector Project MBWT - Final Report

12

Exhaust-air

scrubbing

Post-treatment,landfill

Automatic turning and moisturi-zing of decomposting material

Moisturization withprocess water

Mechanicalconditioned

waste

Exhaust-air

scrubbing

Closed Hall

Vacuum ventilation

Figure 4: Schematic rendition of an intensive aerobic decomposition process

In recent years many countries have adopted

emission standards for the control of flue-gas

emissions from waste incinerating plants. Com-

plying with such standards necessitates very

high process-technological and financial invest-

ments. Such plants are designed for high

throughputs with a view to minimizing the speci-

fic costs.

Mechanical-biological waste treatment facilities,

though, can operate economically for smaller

quantities, as well. MBWT facilities can be

expected to cost a fraction of the outlay for

waste incinerating plants. Moreover, the pro-

cess-technological requirements - in other

words the initial cost of the plant - can, within

certain limits, be defined by the owners / buil-

ders themselves without necessarily having to

fear that the quality of treatment will deteriorate

as a result.

In professional circles MBWT is therefore

discussed as a more economical and less com-

plicated alternative to waste incineration. On the

other hand, especially for large volumes of

waste material, MBWT and waste incineration

can make a good combination. In a basic model

of such an approach, high-energy waste materi-

als such as plastics and composites are separa-

ted from the biodegradable waste. While the

energy content of the former is exploited, the

organic fraction undergoes biological treatment

and subsequent disposal to a landfill.

In many different countries, recent years have

seen the installation of organic waste compo-

sting facilities (primarily for prunings and kitchen

slops). As a rule of thumb, the composting of

separately collected kitchen slops and garden

waste can always be regarded as useful, whet-

her or not mechanical-biological waste treat-

ment is introduced.

2.4 Climatic Factors

Human activities have caused a considerable

increase in the greenhouse-gas contents of the

earth's atmosphere. As a consequence, the

earth's surface is expected to become gradually

warmer over the coming decades (global wam-

ing), in turn giving rise to attendant climatic

changes. Knowing this, the industrialized coun-

tries have adopted the United Nations Frame-

work Convention on Climate Change (Kyoto

Protocol), in which they agree to reduce their

greenhouse gas emissions.

The greenhouse gases that are contributing

most to the greenhouse effect are carbon dioxi-

de (CO2), methane (CH4) and nitrous oxide or

laughing gas (N2O). All three of them occur inter

alia in connection with waste disposal. Table 2,

below, reflects the estimated total emissions of

these gases within the EU, including the respec-

tive fractions attributable to waste disposal.

13

Figure 5: Residual-waste treatment options

Mechanical-biological

treatment

Thermal treatment

Disposal to landfill

high - energy fraction

Untreated waste input

Conventionallandfill

WIP

Slag-dump

MBWT

WIP orenergy rec.

MBWT-landfill

MBWT

Most of the greenhouse effect attributable to

waste management can be ascribed to metha-

ne, which is produced by the anaerobic diges-

tion of biodegradable waste in landfills. Approxi-

mately one-third of all anthropogenic CH4 emis-

sions within the EU derive from that source. By

contrast, only 1 % of the N2O emissions and

less than 0.5 % of the CO2 emissions can be

traced to landfilled waste. Hence, reducing CH4emissions from landfills holds the greatest

potential for reducing greenhouse gas emissions

in the waste-management context.

MBWT allows methane generation to be greatly

reduced. Well-ventilated, long-term aerobic

decomposition emits only about 1 % of the

methane generated by a comparably sized land -

fill full of untreated waste. Anaerobic processes

offer certain advantages over aerobic processes

with regard to climatic effects because the bio-

gas they produce contains a large proportion of

methane and is therefore a useful energy vehi-

cle, and they produce only small amounts of

exhaust air, i.e. off-gas, that can scrubbed befo-

re it is released to the atmosphere.

Another way to reduce methane emissions from

landfills is to cover the older parts of the dump

with a biofilter cap consisting of pretreated,

screened waste. The filter layer helps diminish

the amount of methane that can escape from

the landfill.

Sector Project MBWT - Final Report

14

Greenhouse gas Emissions Greenhousepotential

Total greenhouse potentialof all emissions

Greenhouse potential ofemissions from waste

disposal

Units [Gg] (over 100 years) [Gg] in CO2- equiv. em.(with waste-disposal fraction, in

wt.%, parenthesized)

[Gg] in CO2- equiv. em. (with waste-disposal distribution

parenthesized))

CO2 fossil 3.215 1 3.215 (< 0,5%) 15 (9%)

CH4 22 21 460 (33%) 152 (89%)

N2O 1,05 310 325 (1%) 3 (2%)

Total 3.237 4.000 (4,25%) 170

Table 2: Anthropogenic emissions of CO2, CH4, and N2O within the EU in 1994 [1]

3.1 MBWT Decision-maker's Guide

Within the scope of the sector project, a

compact decision-maker's guide1 on

mechanical-biological waste treatment in deve-

loping countries offers a wealth of relevant infor-

mation. It contains concrete decision-making

aids to help decide whether or not this treatment

method would help improve the waste-disposal

situation under a given set of circumstances.

The main contents of the guide are:

a brief explanation and presentation of the

various stages and processes of MBWT and

of its impacts

a basic approach to the estimation of costs

an explanation of how mechanical-biological

waste treatment fits into municipal waste

management, including a survey of alternati-

ve methods of waste treatment

tools for arriving at an initial decision on

whether or not, and how, MBWT can be

sensibly employed under the prevailing set

of boundary conditions

helpful hints on further lines of action, and

information on pertinent and supplementary

sources of information.

The guide addresses all interested in waste

management in developing countries. This inclu-

des municipal decision-makers as well as diver-

se experts and consultants in the field of waste

management.

3.2 Videos

Serving as an initial introduction to the subject

of MBWT, a presentation in the form of a video

film entitled "Mechanical-biological Waste Treat-

ment in Germany" has been produced by the

sector project. Available in English, Spanish,

Portuguese and Thai, the film illustrates the

basic procedures and the span of MBWT's tech-

nical implementation at various sites in Germa-

ny.

Following an introductory awareness-raising

section on waste disposal in a general context,

MBWT is presented as a potential alternative

with the capacity to ameliorate the relevant envi-

ronmental impacts. The presentation has four

main sections, each dealing with a different sta-

ge of the process:

waste input and control

mechanical conditioning

biological treatment

disposal of residual waste to landfill

Various processes are dealt with, e.g. natural-

draft decomposition, the dome-aeration method,

and some technically more complicated, dyna-

mic, intensive-decomposition approaches.

Another film, produced by Faber, explains the

FABER-AMBRA® process as employed in Ger-

many and Brazil. This film is also included in the

sector project's documentation.

15

3 MBWT Reference Material and Events

1 A PDF version of the guide is available in German, English and Spanish at www.gtz.de/MBA.

3.3 Costing Model

To help estimate the initial investment costs and

the cost of operating an MBWT facility, a costing

module based on a question-and-answer appro-

ach has been developed. It allows the user to

arrive at a cost estimate by entering the relevant

data appropriate to the local situation. The user

should, of course, have some idea of how

MBWT works, because the program includes

multiple-choice questions about such matters as

procedural alternatives.2

The costs to be taken into account are based on

empirical data gleaned from the German / Euro-

pean market. To find out what those costs

would amount to in one's own country, the user

has to estimate and enter a correction factor to

account for, say, the cost of importing the requi-

site mechanical equipment (customs, cost of

transportation, ...). Naturally, the cost of con-

struction must be based on local wage levels.

The program was designed for application to

facilities with throughputs of 20,000 Mg/a and

higher. Sizing of the biological treatment stage

assumes as its treatment target that the biologi-

cal activity of the treated material will amount to

approximately one quarter of that of fresh mate-

rial. While this does not correspond to Ger-

many's stringent requirements for the disposal

of biologically pretreated waste, it does hold the

promise of substantial improvements with regard

to emissions and landfilling space require-

ments.

The program provides an initial overview of the

costs to be expected for various alternative vari-

ants. However, detailed planning with due allow-

ance for the local framework conditions is

necessary for reliable costing.

3.4 Conferences and Seminars

Numerous events dedicated to MBWT were held

in Germany and in the partner countries in the

course of the sector project. They included:

1. a workshop entitled Mechanisch-biologische

Abfallbehandlung in Entwicklungsländern

(mechanical-biological waste treatment in deve-

loping countries) serving to help establish co-

operative relationships with German facility ope-

rators, engineering companies, technology-

transfer organizations and academic institutions.

March 18, 1999, in Eschborn, Germany

2. a sectoral forum entitled Mechanisch-biologi-

sche Abfallbehandlung in Entwicklungsländern

(mechanical-biological waste treatment in deve-

loping countries) held in cooperation with Kno-

ten Weimar, dealing with methods of mechani-

cal-biological waste treatment, as employed

under circumstances specific to developing

countries. July 22/23, 1999, in Eschborn, Ger-

many

3. a training course in mechanical-biological

waste treatment for Thai specialists representing

municipal authorities, held in cooperation with

the Technical Cooperation Project "Solid Waste

Management Programme for Phitsanulok". Sep-

tember 1/8, 1999, in Germany

4. a workshop on mechanical-biological waste

treatment for Brazilian communities and univer-

sities, held in cooperation with "Wilhelm Faber

GmbH" and Prefeitura Municipal de São Se-

bastião. December 6/7, 1999, in São Sebastião,

Brazil

Sector Project MBWT - Final Report

16

2 This information can be found, inter alia, in the aforementioned decision-maker's guide.

5. a workshop for recycling and waste-sorting

cooperatives, held in cooperation with Prefeitura

Municipal de São Sebastião. September 23/26,

2000, in São Sebastião, Brazil.

6. a workshop and training event entitled "Pilot

Project on Waste Management in Atlacomulco",

sponsored by Wilhelm Faber GmbH for the City

of Atlacomulco and other Mexican communities.

September 2002, in Atlacomulco, Mexico.

7. an entrepreneurs' forum entitled "Public Pri-

vate Partnerships (PPP) in the International

Waste Sector", held in cooperation with Knoten

Weimar. The purpose of this forum was to join

with representatives of the industrial sector,

government ministries, promotion institutions,

consultants and experts in evaluating PPP as a

still-young instrument and developing future

strategies. Concrete steps toward improving

PPP as a tool were agreed and implemented.

August 2/3, 2001, in Eschborn, Germany, plus

two "follow-up meetings" by the members of the

initiative on December 6, 2001, in Braun-

schweig, Germany, and on May 15, 2002 at

IFAT.

The partners participating in the pilot projects

held additional training / information events and

seminars for their local specialists. Documenta-

tion of the aforementioned events is available via

the sector project's own documentation and the

website www.gtz.de/MBA.

17

Figure 6: At the entrepreneurs' forum on"Public Private Partnerships (PPP) in theInternational Waste Sector", in Eschborn,Germany

4.1 Short Descriptions of the Projects

Within the scope of the sector project,

various pilot projects were implemented

in cooperation between partners in the project

countries, German enterprises and GTZ. The

main objective of the projects was to appraise

the appropriateness of known German approa-

ches for application in the various countries and

to evaluate the prospects and risks of the tech-

nology in the relevant country. The projects

enjoyed scientific backstopping, and their

results were evaluated by independent experts.

The individual projects are outlined below, and

condensed descriptions of the projects are pro-

vided in the project characterizations attached

to this report.

4.1.1 Pilot project in São Sebastião, Brazil

In cooperation with Prefeitura Municipal de São

Sebastião, the project implemented a mechani-

cal-biological waste treatment (MBWT) plant in

São Sebastião, in the Brazilian State of São

Paulo. São Sebastião, a town of scarcely 50,000

inhabitants, is such a popular tourist destination

that its population swells to over 250,000 during

the main tourist season. With a view to impro-

ving the town's previously inadequate waste dis-

posal capabilities, the German company Wilhelm

Faber GmbH installed an MBWT facility that

works on the basis of the FABER-AMBRA® pro-

cess (cf. Chapter 4.2.3.3).

Firstly, a trial decomposing heap based on the

FABER-AMBRA® process was established and

studied in Rio de Janeiro. Then, in May 2000, a

six-month trial commenced in São Sebastião.

The trial was attended and evaluated both by

Wilhelm Faber GmbH and by independent

experts from GTZ. Some minor adjustments

were made in the process to accommodate

local factors, with a bearing on, for example,

homogenization and moisturizing of the waste

and disposal of the process water. Once the

process was seen to have demonstrated its fun-

damental suitability in the course of trial opera-

tion, MBWT was successively expanded and

integrated into São Sebastião's waste manage-

ment system.

Now, since April 2002, all domestic waste arri-

ving at the landfill undergoes mechanical-biolo-

gical pretreatment, and no more waste is depo-

sited at the old dump. The old dump has since

been profiled and covered with cohesive soil.

After that, additional biotreatment windrows

were established on the covered area, and all

pretreated waste is now being emplaced in

separate sections of the landfill. Operation of

both the landfill and the MBWT facility has been

privatized. The City of São Sebastião has char-

ged Faber with providing technical support for

the MBWT.

4 MBWT Pilot Projects

Sector Project MBWT - Final Report

18

Figure 7: Mechanical-biological waste treatment using theFABER-AMBRA® process in São Sebastião

4.1.2 Pilot project in Phitsanulok, Thailand

In November 2001 a pilot project at the Phit-

sanulok municipal landfill was commenced on

the basis of a GTZ-commissioned feasibility stu-

dy produced in 1999 on the suitability of mecha-

nical-biological waste treatment for the city. The

purpose of this experiment was to demonstrate

that the FABER-AMBRA® process can also be

successfully applied in cases involving very

moist, weakly structured waste materials contai-

ning large amounts of plastics. Another goal was

to clarify the extent to which high rates of preci-

pitation during the rainy season would cause

problems with the open-air decomposing heaps.

The project was conducted in cooperation with

the City of Phitsanulok and with the support of

the Technical Cooperation project "Thai-German

Solid Waste Management Programme for Phit-

sanulok."

The MBWT process employed is basically the

same as in São Sebastião. The waste is homo-

genized at a rate of 50 Mg/d in a mobile drum

provided by Faber. Since the project is still in its

pilot phase, no ultimate throughput targets are

being achieved yet. The pilot project is being

backstopped by Faber and independent experts

from GTZ. The first few windrows were found to

be suffering a lack of oxygen supply. This was

attributed to inadequate reinforcement and profi-

ling of the biotreatment areas, coupled with

insufficient load-carrying capacity of the base-

course pallets. This gave rise to numerous opti-

mizing measures designed to improve the sup-

ply of oxygen to the heaps. Now the results of

subsequent tests confirm that the decomposi-

tion process is proceeding satisfactorily. The

process adaptation is being monitored by way

of extensive temperature profiling and gas-com-

position measurements.

Initially, the pilot project was supposed to last

one year, but its duration has since been exten-

ded to mid-2003 to allow unequivocal demon-

stration of the effectiveness of the now comple-

ted optimizing measures during the rainy season

too. Completion of the trial-operation phase will

be followed by negotiations regarding continua-

tion of the process and its implementation into

the local waste management system.

4.1.3 Scale-model MBWT trial in

Al-Salamieh, Syria

The organic fraction of waste collected in Al-

Salamieh amounts to approximately 70 %. Al-

Salamieh has an urgent demand for soil amelio-

ration, so people there are very interested in

turning at least part of that fraction into com-

post. The Al-Salamieh model experiment there-

fore included an appraisal of various options for

generating useful compost fractions via mecha-

nical-biological treatment of household and

commercial waste inputs.

19

Figure 8: Mechanical-biological waste treatment usingthe FABER-AMBRA® process in Phitsanulok

Considering the composition of the waste, the

pedological situation and the economic context,

together with the country's dependence on

imported fertilizers, the generation of compost

from waste makes economic sense in Syria, and

is not unknown there. However, since the con-

ventional method of composting the aggregate

waste input had proved unable to yield compost

of the required quality and environmental safety,

a mechanical-biological waste treatment con-

cept was applied in an attempt to stabilize the

residual waste while obtaining a high-quality

compost fraction, and hence reducing the ulti-

mate amounts of waste destined for the landfill.

Unlike other pilot-scale field trials, in which pre -

treatment is intended to improve the disposal

situation, the Al-Salamieh experiment focused

on obtaining a good soil conditioner. The main

objectives of the experiment were:

1. to demonstrate and explain different process-

technological variants for MBWT and compost

production by comparison with currently

employed concepts,

2. to portray the general legal situation regarding

the operation of an MBWT facility and the use of

the subfractions obtained,

3. to analyze and characterize the obtainable

compost fraction,

4. to appraise the market for subfractions ob-

tained,

5. to estimate the anticipated costs of MBWT

enlisting local technologies,

6. to prepare an ecobalance of various disposal

options.

The properties of compost are heavily depen-

dent on both the nature of the inputs and the

composting process. Pretreatment (separate

collection and/or removal of disturbants, un-

wanted materials and - optionally - recyclables,

comminution, etc.) and the composting condi-

tions therefore had to be selected to produce

composts of defined quality for defined purpo-

ses, and to enable sustained achievement of the

requisite quality parameters. For example, diffe-

rent windrows were built up of summer waste

and winter waste, the compositions of which dif-

fer considerably. All in all, approximately 220 Mg

of waste from garbage collection in Al-Salamieh

was employed in the experiment. In addition to

the common-landfill variant as the reference

embodiment, three windrows composed of

mixed, coarsely presorted household waste and

separately collected biowaste were investigated.

The waste was piled up in pressure-ventilated

windrows of trapezoidal cross section. To keep

the windrows from drying out, and in order to

minimize the odor nuisance, the heaps were

covered with a semi-permeable tarpaulin.

Sector Project MBWT - Final Report

20

Figure 9: Composting windrow in Al-Salamieh,with cover and forced ventilation

The experiments demonstrated the suitability of

the procedural approach employed for MBWT

and hence for the production of high-quality

compost. With regard to the quality of the matu-

re compost, the study also illuminated the

importance of either collecting biowaste separa-

tely or subjecting it to a similarly oriented form

of pretreatment.

A large-scale pilot project based on the results

of this model experiment is presently in prepara-

tion for validating and adjusting the process.

The goal is to build and operate an MBWT facili-

ty in Al-Salamieh with a capacity of 15,000 -

20,000 Mg/a. Appropriate technical and politi-

cal-institutional embodiment measures are being

provided to ensure the long-term efficiency of

the MBWT facility. GTZ will help finance and

implement the training and upgrading measures

for the various target groups, the production of

training and reference materials, the promotion

of public awareness, and the provision of con-

tacts in Syria. The firm W. L. Gore will be

responsible for building and operating the waste

treatment plant, for coordinating the various

parts of the system, and for adapting them opti-

mally to the local situation. The entire measure

will enjoy the scientific backstopping of the Uni-

versity of Kassel, Waste Technology Faculty.

4.1.4 Other projects

In addition to the aforementioned projects,

which focus on the field-testing of MBWT, the

sector project also provided support to various

other projects of similar thrust.

Pilot project in Atlacomulco, Mexico

The purpose of this project is to introduce an

integrated, sustainably safe and reliable form of

waste management with integration of the infor-

mal sector. To this end a waste-sector training

and upgrading program is being implemented in

the City of Atlacomulco and its surrounding

communities. The training and upgrading pro-

gram consists of three components:

composting,

sorting of recyclables and management of a

microenterprise (Microempresa),

treatment of waste inputs according to the

MBWT process.

The overall concept envisages the coupling of

composting, recovery of recyclables, and MBWT

(using the FABER-AMBRA® process). The inten-

tion is to implement an ecologically optimized

scheme that will simultaneously make an impor-

tant contribution to poverty reduction. Until now,

most salvaging has been done by the informal

sector (waste pickers = Pepenadores). The com-

posting, recycling and sale of compost and

secondary raw materials will substantially impro-

ve the latter's income situation.

21

Promotion of ecologically sound waste manage-

ment in Colombia

The waste management engineering consultants

Ingenieurbüro für innovative Abfallwirtschaft (ia)

GmbH, in cooperation with B.A.U.M. TRACOM

Ltda, in Bogotá, and with GTZ, have implemen-

ted a pilot project in Armenia (capital of Quindío

Department, Colombia) for introducing an inte-

grated approach to sustainable development via

theory and practical training in the areas of

"integrated waste management" and "sustain-

able waste management". The project objectives

were to establish a technical college and to

plan, build and operate a model MBWT facility

with a practical training mandate.

After sorting and screening, the material is

homogenized in a mixing drum and then com -

posted in bamboo composting bins. The project

also qualified trainers for turning out future spe-

cialists. A further focal point of the project was

to compile the experience gained and make it

available to interested parties across South

America via the internet portal "Foro-Z", the

waste-management knowledge portal for Latin

America" (www.foro-z.com). The project has

been completed, and further cooperation and

the development of additional projects within the

region are planned.

4.2 Results and Experience Gathered

from Pilot Projects

The essential results of the pilot projects are

discussed below, with special attention given to

the projects in São Sebastião, Brazil; Al-Sala-

mieh, Syria; and Phitsanulok, Thailand. These

pilot projects have either already been comple-

ted, or soon will be, and they have yielded volu-

minous data. The pilot projects in Phitsanulok

and São Sebastião come close to normal opera-

tion in terms of their quantitative throughput3

and equipment endowment, so the results are

reliable with regard to costs and the use of

machinery. The model experiment in Al-Sala-

mieh involved relatively small amounts of waste,

so its results do not necessarily apply uncondi-

tionally to normal operation as far as costs and

the use of machinery are concerned. On the

other hand, the model project in Al-Salamieh

enjoyed very intensive scientific backstopping,

and the data yield is accordingly voluminous.

Sector Project MBWT - Final Report

22

Figure 10: Training for Recicladoresat the scale-model MBWT facility inArmenia, Colombia

3 In Sao Sebastiao, all waste arriving at the landfill is now pretreated. In Phitsanulok, approximately 30 % of the waste arriving at the landfill undergoespretreatment in connection with the pilot project.

4.2.1 Project preparation

The pilot projects were based on feasibility stu-

dies in which the local boundary conditions (e.g.

the fundamental waste-management and econo-

mic data) were collected and a project concept

developed. The main objectives of the pilot pro-

jects, which were implemented on the basis of

the aforementioned feasibility studies, were

to verify the assumptions of the feasibility

study and clarify open questions,

to test the process and adapt it to the local

situation as necessary,

to train local personnel and demonstrate the

process and its results in the partner coun-

try, and

to assess the chances and risks of the pro-

cess employed in the project area.

4.2.2 Monitoring programs

4.2.2.1 Basic principles

The time history of the biological process taking

place within the biotreatment heap can be des-

cribed by means of various parameters:

Temperature

The decomposition process liberates energy in

the form of heat, and the temperature increases

in tandem with the activity of the microorga-

nisms. This produces a typical time history of

temperature over the duration of the decompo-

sition process. At the same time, the biological

efficiency of the microorganisms is also a func-

tion of temperature, reaching its peak at appro-

ximately 70°C during the intensive-decomposi-

tion phase.

Continuous monitoring of the temperature

makes it possible to detect deviations from the

optimal decomposition process and to take

appropriate countermeasures to improve the

conditions of decomposition (e.g. ventilation,

moisturizing, turning). The temperatures were

monitored by means of probes (or sampling

gauges) penetrating some 1.5 m into the heap.

The temperatures were measured once a week.

23

Figure 11: A typical decompositiontemperature curve

The experience gained in the pilot projects

shows that it can take several years to progress

from the initial study to normal operation. In

addition to financing matters, there were nume-

rous other causes of delay, e.g. clarification of

customs issues for the importing of equipment,

adaptation of the process technology to local

conditions, clarification of site availability, and

lengthy licensing and decision-making proces-

ses.

70

60

50

40

30

20

10

0

Time history of decomposition temparature

Tem

per

atur

e (°

C)

Time

Inte

nsiv

e d

eco

mp

osi

tion

pha

se

Po

st-d

eco

mp

osi

tion

pha

se

Ter

min

al d

eco

mp

osi

tion

pha

se

Pre

-dec

om

po

sitio

n-p

hase

Gas evolution

Aerobic decomposition is a process in which

oxygen-dependent microorganisms break down

organic substance. The process liberates carbon

dioxide, water and heat, leaving behind a resi-

dual organic mass. If the supply of oxygen is

interrupted, the process turns anaerobic, and

the resultant fermentation becomes recognizable

by the generation of methane. Consequently, by

monitoring the oxygen, carbon dioxide and

methane levels in the heap, the operator can tell

whether or not it is getting enough oxygen, how

well the gases resulting from the biological pro-

cesses are escaping, and whether or not the

aerobic decomposition process is encountering

any problems.

Solids analysis

The processes of organic decomposition taking

place in the biotreatment heaps can be monito-

red by various analytical methods of determining

such factors as the total organic carbon content

of the waste (TOC) , its gas formation rate

(GB21) and its dynamic respiration activity level

(AT4).

4.2.2.2 Implementation via pilot projects

Prior to starting the pilot projects, a monitoring

program was elaborated in collaboration with

the various actors. In São Sebastião and Phits-

anulok, monitoring and evaluation were carried

out by both Faber and independent experts

acting on behalf of GTZ. In Syria, the University

of Kassel, Waste Technology Faculty, provided

scientific back-stopping for the project.

Sector Project MBWT - Final Report

24

Table 3: Proposed monitoring program for thepilot-scale field trial in Phitsanulok

Frequency Meas. point

Input

Visual inspection -

Temperature in the heap -

Moisture in the heap -

Height

-

Ambient temperature -

Precipitation -

-

Gaseous emissions -

Carbon dioxide -

Oxygen -

Nitrogen -

Methane -

-

Water content (solids)

Ignition loss (solids)

TOC (solids) ( )

TOC (eluate)

Respiration activity (AT 4)

Dayly Weekly Monthly Quar-terly

( )

Output On Site Lab

Gas format. rate (GB21)

pH

COD (eluate)

BOD5

AbfAblV criteria*

Density/water content

-

Process water -

Quantity

Conductivity -

pH -

NH4, NO3, TKN -

BOD5 -

COD -

* German directive governing the ecologically viable disposal of municipal solid waste

In addition, numerous other data of importance

for evaluating the process and for further plan-

ning purposes were collected, e.g.:

mass/bulk and volume analyses

process water quantification

equipment operation and downtime

personnel working hours

operational resource requirements

The results of the pilot projects show that the

locally available resources do not suffice for

conducting the tests that are necessary for

assessing the progress and results of the

decomposition process. The specific standards

and facilities required for the performance of

waste analyses are largely lacking in the coun-

tries in question. The analysis of solid waste, for

example, is very complicated and can only be

performed by specialized laboratories. Conse-

quently, most of the pretreated waste from the

pilot projects was analyzed in Germany.

4.2.3 MBWT processes employed in the

pilot projects

Many different MBWT processes have been

developed in Germany in recent years. However,

most of them are oriented to the requirements of

German and European markets and standards,

while some additional criteria have to be consi-

dered for applications in developing countries.

25

The most important data were published in the

experts' reports and can be accessed, inter

alia, via the GTZ MBWT website

www.gtz.de/MBA/English/index.html.

Figure 12: Temperature monitoringwith a sampling gauge in Phitsanulok

4 An overview of processes and providers can be found in [2] and [3].

4.2.3.1 Technology selection criteria

Experience shows that caution is of the essence

for transferring waste treatment technologies

from Germany to developing and threshold

countries. In the past, imported technologies

have often worked well only as long as they had

the benefit of external technical support. There

are various reasons for this, and they apply not

only to financial aspects, but to legal, organiza-

tional and cultural factors as well. First of all, the

basic tenets of development cooperation in the

area of waste management - such as those des-

cribed in the BMZ sector concept for waste

management [4] - must be adhered to. For

example, technologies must be selected in con-

sideration of the fact that, for many people in

many countries, waste-picking is the sole avai-

lable means of making a livelihood.

Hence as far as possible, MBWT projects should

be implemented in a manner to promote better

working conditions for these people, and not to

rob them of their basis of subsistence. Another

essential criterion is that the technology employ-

ed must be affordable. This requirement sub-

stantially diminishes the range of potential pro-

cesses. In Phitsanulok, for example, the charac-

teristics of the waste (high water content, little

structural material, large share of waste in pla-

stic bags) made it appear expedient to employ a

rather complex process technology (e.g. inclu-

ding fermentation of residual waste). On the

other hand, the boundary conditions still prevai-

ling in Phitsanulok made it unlikely that such a

costly approach would be successful with

regard to the financial and technological sustai-

nability of waste management. Consequently,

the only technologies with a potential for suc-

cess were those that would allow the targeted

waste treatment objectives to be achieved with

the lowest possible initial investment and

operating costs,

the lowest possible, locally feasible mainte-

nance and repair expenditures,

the most lenient possible operating require-

ments.

The processes employed in the pilot projects

largely satisfy the aforementioned criteria. It was

also possible to enlist the assistance of German

enterprises and institutions for implementing the

pilot projects. This is not to say, of course, that

none of the other MBWT technologies that were

not field-tested within the scope of the sector

project would be suitable for application in

developing countries.

Sector Project MBWT - Final Report

26

Figure 13: Waste pickers at the Phitsanulok landfill

4.2.3.2 The Al-Salamieh scale-model trial

The following approach to mechanical-biological

treatment and composting of inputs amounting

to 15,000 Mg/a was developed on the basis of

the scale-model trial:

Input

At first, the waste is collected in the normal

manner (mixed collection) and delivered to the

waste treatment site. Eventually the biowaste is

to be collected separately.

Waste comminution

For successful biological treatment, the collec-

ted waste first has to be removed from the pla-

stic bags. To this end a special comminutor

(homogenizing drum), which is to be built in

Syria, is needed to rip open the bags in such a

manner that the recyclables are not rendered

useless or irretrievable by excessively destructi-

ve handling.

Sorting

After the bags are ripped open, the recyclables

and the disruptive materials (disturbants and

unwanted materials) have to be sorted out by

hand. Judging by the waste composition already

ascertained, it should be possible to recover

approximately 150 Mg of scrap metal and 100

Mg of used glass per year as secondary raw

materials. That corresponds to roughly 1 % of

the total input. Theoretically, this would yield

revenues amounting to some PS 1 million

(approx. EUR 20,000) per annum.

Piling and operation of the compost heaps

Following mechanical conditioning, the material

to be composted is piled into heaps with the aid

of a wheel loader. Suitably reinforced (concreted)

composting areas with integrated ventilating

ducts (possibly in the form of channels in the

concrete to accommodate flexible vent pipes

and to drain off the resultant press water and

leachate) are needed to set up the heaps. The

finished heaps are then covered with a semi-

permeable tarpaulin and pressure-ventilated.

Compost recovery

At the end of a 14-week composting process

the material is comminuted once again and

screened to a size of 20 mm. Here, too, a wheel

loader (or a grab excavator) is needed for fee-

ding the compost into the appropriate comminu-

tors.

Landfilling

The oversized material is dumped at the landfill.

Removal of the recyclables, in combination with

the decomposition of organic substance, redu-

ces the volume and weight of the original waste.

This saves space at the landfill and is therefore

highly desirable.

27

Figure 14: Compost heaps during the model experiment in Al-Salamieh

4.2.3.3 The FABER-AMBRA® process in

São Sebastião and Phitsanulok

The individual steps of the patent-protected

FABER-AMBRA® process, which is essentially

based on the natural-draft, chimney-effect pro-

cess developed in Germany, are explained

below.

Coarse sorting

The first step is to remove from the incoming

waste any bulky objects that could cause dama-

ge to the homogenizing drum. Recyclables can

also be sorted out at the same time.

Homogenizing

Further mechanical conditioning of the waste

takes place in a mobile homogenizing drum that

Faber built especially for this purpose.

This step is a crucial element of the process, as

it fulfills the following functions:

Homogenization of the waste introduced

by the wheel loader:

The agitation caused by the turning of the

drum mixes, i.e. homogenizes, the waste.

Good mixing requires some 30 to 45 minu-

tes.

Tearing open of the garbage bags:

As the drum turns, teeth on the inside tear

open the bags of garbage, some of which is

wrapped in two or more bags. A comparison

of freshly arrived waste with the results of

homogenization shows that this approach

worked well in the pilot projects, with only a

small number of garbage bags either not

torn open or only insufficiently so.

Moisturizing the waste:

Water can be added to the waste during the

homogenization process to give it the right

moisture content for the biological proces-

ses. The required amount of water depends

on the nature of the waste inputs. In Phit-

sanulok, it was not necessary to add any

water at all.

Transfer of the waste to the composting

area: After homogenization, the waste is

transferred to the biotreatment area while

still in the drum.

Building the heaps

The truck carrying the homogenizing drum

dumps the homogenized and, as necessary,

moistened waste in front of the pallet-covered

heap-building area by turning the drum back-

wards. A backhoe-equipped hydraulic excavator

picks up the waste and forms it into biotreat-

ment heaps on top of the pallets.

Sector Project MBWT - Final Report

28

Figure 15: Homogenizing drum at work in Phitsanulok

The vent pipes are laid out approximately 4 m

apart. The heaps are piled between 1.80 and

2.50 m high5, depending on the nature and

structure of the waste. Regarding the space

requirement for the heaps, roughly 1 m² per ton

of waste input can be taken as a rule of thumb

for calculation purposes. If the heaps are torn

down before the scheduled end of biological tre-

atment, the organic fraction will not have time to

undergo full biological decomposition.

Covering the heaps

The completed heaps are covered with a layer

of biofiltering material. In Germany, the biofilter

is obtained by screening the pretreated waste.

That, however, necessitates the use of a corre-

spondingly powerful screening unit, but no such

unit was available for the pilot projects. Alterna-

tively, wood scraps (eucalyptus bark) are used

in São Sebastião and coconut shells in Phit-

sanulok. Covering the heaps serves the

following purposes:

uniform heat-soaking of the heaps thanks to

the insulating effect of the cover,

reduction of odors escaping from the heaps

with the vented air,

achievement of a more uniform distribution

of moisture,

partial decomposition of organic carbon

compounds in the biofilter,

better optical appearance of the compost

heaps,

provision of a vermin barrier.

The hydraulic excavator is used to cover the

heap with a 20 - 40 cm-thick layer of biofiltering

material.

29

Figure 16: Waste from Phitsanulokbefore and after homogenization

Figure 17: Piling the waste for biologi-cal treatment in Atlacomulco, Mexico

5 Both in Phitsanulok and in Sao Sebastiao, the heap heights were reduced to improve the supply of oxygen.

Tearing down the heaps

At the end of the biological treatment phase, a

mobile excavator is used to tear down, i.e. to

disassemble, the heaps. In removing the materi-

al, care is taken to preserve as many of the pal-

lets and vent pipes as possible for reuse.

Emplacement of pretreated waste

The residual waste is loaded onto a truck and

dumped at the landfill. If available, a compactor

is used to place the material. If not, a traxcava-

tor or bulldozer will do the job. Optimal landfil-

ling requires that the waste be placed in very

compact thin layers (= onion skin tipping).

4.2.3.4 Evaluation of the technologies

employed

FABER-AMBRA® process

Both in São Sebastião and in Phitsanulok, the

pilot projects confirmed that extensive stabiliza-

tion of pretreated waste can be achieved with

simple equipment and comparatively low initial

investment and operating costs by adopting the

FABER-AMBRA® process. Not only did the

FABER-AMBRA® process work well in the pilot

projects, it was also retained for normal opera-

tion in São Sebastião, where MBWT has since

radically improved the situation at the landfill.

Nevertheless, some aspects still require further

clarification and development:

Sensitivity to high rates of precipitation

The uncovered heaps were found to react

more or less sensitively to high rates of pre-

cipitation, depending on the nature of the

waste. This could even progress to the point

that anaerobic processes begin to take pla-

ce within the heaps (cf. Chapter 4.2.5.2).

Faber is presently investigating various ways

to minimize the effects of weather conditions

by way of reasonable technical and financial

inputs.

Pallets

In Phitsanulok, the quality and physical cha-

racteristics of the pallets proved to have a

decisive impact on the decomposition pro-

cess. In Thailand, suitable pallets are com-

paratively expensive and often serve as

secondary raw material for other purposes.

Consequently, various alternatives to the use

of such wooden pallets should be investiga-

ted.

Biofilter

Various materials were used for making bio-

filters in the pilot projects. The coconut

shells used in Phitsanulok are waste pro-

ducts and available free of cost. Conversely,

the eucalyptus bark used in São Sebastião

is comparatively expensive and could be put

to other uses. It would therefore be advisa-

ble to investigate some alternative biofilter

materials.

Homogenizing drum

The rotary drum vehicles used by Faber

were imported from Germany. The homoge-

nizing drum is the most technically elaborate

part of the FABER-AMBRA® process and

not yet available in the project countries.

However, the drum is needed to make the

input material suitable for biological treat-

ment. Its operation requires qualified per-

sonnel and regular maintenance, because

replacement vehicles are very expensive and

difficult to obtain. Hence efforts should be

made to develop locally available, more

inexpensive alternatives.

Gas monitoring

Monitoring the generation of gas with a

handheld measuring instrument has proved

rather unreliable. Some simple but reliable,

locally appropriate method of gas measure-

ment needs to be developed.

Sector Project MBWT - Final Report

30

Al-Salamieh

The process concept also worked well in Al-

Salamieh. The decomposition process and its

results are in line with expectations. Covering

the heaps with an air-permeable membrane

made it possible to dispense with supplemen-

tary moisturizing of the heaps. While this does

make the process somewhat more complex

than the FABER-AMBRA® process, it also offers

advantages for applications in arid climates as

well as in areas with abundant precipitation. In

Al-Salamieh it is planned to integrate the field-

tested process into normal operation. However,

the requisite equipment will have to be locally

redesigned.

Provision of special-purpose equipment for

waste treatment

No special waste-treatment equipment - waste

comminutors, homogenizing drums, screeners,

etc. - is to be found in any of the project coun-

tries. That, of course, means that such equip-

ment either has to be imported or fabricated

locally as one-off items. For imported equip-

ment, proper maintenance and spare-parts pro-

curement must be assured for the long term,

and any locally fabricated equipment has to

meet certain quality standards with regard to

corrosion resistance, mechanical strength, etc.

Within the scope of the pilot projects it was not

possible to determine the extent to which local

fabrication of low-cost equipment meeting these

quality standards could actually be realized.

In Syria, the comminutors and screeners have

also been earmarked for local fabrication and

integration into normal operations. Inquiries

among local contractors indicate that fabrication

of the equipment in Syria would cost some

90 % less than it would to import the items from

Germany. Whether or not these price estimates

would hold true in actual practice, and the

extent to which the finished items of equipment

actually meet the set requirements, remains to

be seen. In Brazil, options for local manufacture

of a homogenizing drum are being explored.

4.2.4 Operation of an MBWT facility

Extensive MBWT processes are characterized

by the use of "simple" technology. However, that

does not mean that such processes are "simple"

to control. On the contrary. It is probably more

difficult to create optimal conditions for the bio-

logical degradation of organic material in an

uncomplicated, extensive process than it would

be in a more intricate, intensive one. For exam-

ple, in any country where composting and other

comparable techniques are not widely dissemi-

nated, it takes time to build up the requisite

know-how. Hence one major constituent of all

pilot projects was to provide training for the

local personnel.

31

4.2.4.1 MBWT personnel requirements

For an MBWT process to achieve good results,

it must be managed with due competence and

commitment. In addition to normal managerial

and leadership skills, the operator must also

have the experience needed to optimally control

a biological decomposition process. The per-

sonnel needed for the other work must have

qualifications comparable to those of civil-

engineering workers (e.g. shovel men, truck dri-

vers, mechanics).

4.2.4.2 Training

Both in São Sebastião and in Phitsanulok, Faber

not only provided technical support for the

MBWT facility, but also trained the local workfor-

ce. During the first months of the project, Faber

personnel were in constant attendance. That

was also the time frame of the intensive training

phase for the workers. In both pilot projects, the

per-sonnel were hired by the municipal authori-

ties. Their theory-based training encompassed

explanations of the mechanical and biological

steps of the process and of the various machi-

nes, but their actual practical training took place

directly at the landfill with the MBWT in opera-

tion. The engineers and political decisionmakers

involved were invited to attend information

workshops and seminars covering both the

theoretical and practical fundamentals and

objectives of the MBWT process.

Thereafter, Faber's backstopping inputs were

gradually reduced from month to month, while

the local employees just as gradually assumed

responsibility for operating the MBWT facility. All

the while, Faber operatives remained on call to

help the local personnel and ensure that opera-

tional safety and reliability was maintained.

Sector Project MBWT - Final Report

32

Personnel requirementJob scope

Main season (4 months)

Off season (8 months)

Technical management 2 1

Machine operators (excavator,wheel loader, drum, truck)

10 5

Laborers 6 4

Total 18 10

Project phase Duration Work inputs by Faber Recycling

Introduction and training 1 month uninterruptedly from May 8 - June 2, 2000

1st backstopping phase 2 months twice weekly, June 5 - Aug. 4

2nd backstopping phase 3 months once weekly, Aug. 7 - Nov. 3

3rd backstopping phase 6 months twice monthly, Nov. 6 - Apr. 30, 2001

Table 4: Personnel requirements for MBWT opera-tions in São Sebastião (throughput: 30,000 Mg/a)

Table 5: Backstopping work scope for Faberduring the one-year implementation phase in

São Sebastião

Figure 18: Training fortechnical personnel at the

Phitsanulok landfill

4.2.4.3 Integration into the organizational

structures

In developing and threshold countries, it is rat-

her an exception to the rule to encounter well-

qualified, well-motivated personnel working at

landfills. Consequently, it is not only necessary

to teach the local staff how to operate the

MBWT facility, it is also necessary to establish

better-paying job slots for better-qualified per-

sonnel.

On the administrative side, the prerequisites for

effective, controlled operation of the landfills and

MBWT facilities must be established. This inclu-

des on the one hand proper organization of the

operation (responsibilities, assignments, material

procurement, budgeting), and on the other hand

performance control.

The findings show that the existing structures

and the available personnel suffice only for low-

quality operation of MBWT facilities. Numerous

problems were encountered, including frequent

cases of people not showing up for work, orga-

nizational deficits (lack of pallets or other resour-

ces), defective vehicles, and the pulling of per-

sonnel for other assignments. Both in São Seba-

stião and in Phitsanulok, the early phase of ope-

ration therefore achieved only 30 - 40 % of the

theoretically possible throughput.

33

September October

Date 25 26 27 28 29 30 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Day of week W T F S S M T W T F S S M T W T F S S M T W T F

Wheel loader*

Excavator*

Rotary drum*

Veh. operator**

Laborer**

*defective Machine ** absent personnel half day full day

60

50

40

30

20

10

0

MBWT capacity utilization rates and causes of outage in Phitsanulok, Thailand

Tre

ated

was

te [M

g/d

]

Figure 19: Theoretically achievable and actu-al throughput at the MBWT facility of the

Phitsanulok pilot project

planned target throughput

Considering the given structures and the organi-

zational problems encountered in São Sebastião

and Phitsanulok, further operation of the MBWT

facility by the local staff with no outside help fol-

lowing completion of the pilot phase would have

been inconceivable.

In the meantime, operation of the MBWT facility

and landfill in São Sebastião has been priva-

tized. Faber has contracted to provide all the

requisite special-purpose operating equipment

and to remain available for providing follow-up

assistance and controlling functions. Privatiza-

tion has had positive effects on the MBWT facili-

ty's operation, because the economic incentive

gives the operator more reason to be interested

in efficiency than the previous municipal

employees were. The workers are at home in

their jobs now and appear to be very well moti-

vated. Indeed, the clear-cut allocation of respon-

sibilities and the designation of supervisory per-

sonnel have significantly improved the operatio-

nal organization. Impediments such as a lack of

operational resources or having the city's landfill

personnel fail to show up for work due to orga-

nizational or motivational problems no longer

occur. Moreover, the manager of the operating

company has professed an interest in introdu-

cing MBWT for other waste projects as well.

This concept appears to be ensuring the suc-

cess of MBWT's sustainable implementation in

São Sebastião.

4.2.5 Chronology and results of aerobic

decomposition

Biological decomposition of the organic con-

tents of the waste input is the central step of the

MBWT process. Since there is no way to control

the processes of decomposition directly in the

course of aerobic waste treatment, various para-

meters are used to describe its progress (cf.

Chapter 4.2.2). The results of aerobic decompo-

sition in the pilot projects are discussed below

on the basis of these parameters.

4.2.5.1 Time history of in-heap

temperatures

In all pilot projects, the temperature inside the

heap was continuously monitored at various

points. During the most intensive phase of orga-

nic decomposition, the in-heap temperature

should be situated between 55°C and 70°C. If

the temperature drops below 50°C for any con-

siderable length of time during the first phase of

decomposition, something is probably slowing

down or disrupting the processes of decay. Low

temperatures during the initial phase may also

indicate excessive moisture (and the possible

resultant occurrence of anaerobic processes).

As time passes, the in-heap temperature gradu-

ally declines, as shown in the following diagram,

which exemplifies the time history of temperatu-

re in all decomposing heaps of the Al-Salamieh

field test in Syria.

Sector Project MBWT - Final Report

34

Most of the temperatures measured are situated

within the indicated spectra, which neatly match

the ideal temperature curve shown in Chapter

4.2.2.1 for the biological decomposition proces-

ses. The rapid increase in temperature during

the first two weeks is quite conspicuous. This

most intensive phase of the process lasts as

long as approx. 40 days, while the subsequent

post-decomposition phase lasts considerably

longer. Remarkably, the first and second turn-

ings of the heaps produce no distinct rise in

temperature.

The temperature curves obtained for FABER-

AMBRA® heaps differ from those tested in Syria

by reason of their longer decomposing times

and passive aeration. In a FABER-AMBRA®

heap the temperature rises quickly at the begin-

ning of the process and then remains between

55°C and 70°C for approximately five months,

after which it slowly declines.

35

Time history of temperatures in all heaps as a function of decomposing time, in Al-Salamieh, Syria

Tem

per

atur

e (°

C)

0 10 20 30 40 50 60 70 80 90 100

Time (days)

80

70

60

50

40

30

20

10

0

1st turning 2nd turning 3rd turning

90

80

70

60

50

40

30

20

10

0

Time history of in-heap temperaturesin Sao Sebastiao, Brazil

Tem

per

atur

e (°

C)

Jan Feb Mar April May Juni Juli Aug Sep Oct Nov

2001

T1 T2 T3 Umgebung

Figure 20: Time history of in-heap temperatures in the Al-Salamieh scale-model trial

Figure 21: Time history of in-heap temperatures in São Sebastião

4.2.5.2 Effects of rainy season on

the temperature curve

The temperature readings taken in Phitsanulok

show that heavy precipitation of the kind that

often occurs during the rainy season there has

definite impacts on the heat balance of the

heaps.

The in-heap temperature is seen to drop precipi-

tously with the onset of heavy rains in early Sep-

tember, while the light rains before that time had

no detectable effect on the temperature. Begin-

ning around mid-September, the temperature

rises slowly but surely until more heavy rains in

late October again quench the heap. After that,

the temperature recovers again, rising to bet-

ween 55°C and 60°C, which corresponds well to

the age of the heap. During the month of Oct-

ober, samples were taken from the heaps for

use as specimens in determining the heaps' bio-

logical efficiency. The samples display high moi-

sture contents ranging between 55 % by weight

and 62 % by weight. Various ways and means

of keeping the heaps from becoming waterlog-

ged were considered and developed:

put less water in the homogenizing drum

ensure good off-flow of process water from

the heaps by paving the biotreatment area

and providing adequate slope (at least 3 %)

choose the pallets for the ventilating course

with care as regards quality and durability

reduce the height of the heaps

apply a thicker layer of biofilter material

The use of different geotextiles for covering the

heaps during the rainy season is presently being

investigated.

Sector Project MBWT - Final Report

36

80

70

60

50

40

30

20

JUNI JULI AUG OCT NOV DEC JAN

300

250

200

150

100

50

0

Time history of temperatures in heap C, measuring point 2 Beginning of decomposition process: May 17, 2002

incl. weekly precipitation yields and ambient temperature

Tem

per

atur

e (°

C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Process duration [weeks]

Precipitation Temp. 2s, 0,8m

Temp. 2l, 1,2m Temp. Air

Pre

cip

itatio

n (m

m/w

eek)

Figure 22: Time history of temperatures in a FABER-AMBRA® heap exposed to heavy precipitation

4.2.5.3 Gas composition

The composition of the biogas that is being

generated within the heap can provide informa-

tion on the quality of the composting process

and on any disturbances which may be affecting

it. First of all, aerobic decomposition is highly

dependent on an adequate supply of atmos-

pheric oxygen. In an ideal case, the oxygen con-

centration within the heap should amount to at

least 10 % by volume. As the microorganisms

digest the organic matter, they respire oxygen

into carbon dioxide. Accordingly, the CO2 con-

centration within the heap increases markedly

and may even reach levels of the order of 10 %

by volume. Methane is an indicator of anaerobic

decomposition processes and has been identi-

fied as a climaterelevant gas. In a well-functio-

ning windrow, the methane concentration should

remain at roughly 1 % by volume most of the

time, though short-lived higher concentrations

may occasionally occur.

If the oxygen concentration drops below the

aforementioned 10 % by volume, and if the CO2concentration rises significantly above 10 % by

volume at the same time, either the heap is not

getting enough fresh air, or the off-gas is not

escaping as well as it should. If the methane

concentration is also higher than normal for any

considerable length of time, the aerobic decom-

position processes are apparently disturbed.

The following illustration visualizes the relation-

ship between oxygen content and CO 2 concen-

tration in the light of selected readings from

Phitsanulok.

37

25

20

15

10

5

0

Relationship between oxygen content and carbon dioxide concentration Case in point: Phitsanulok, Thailand

Gas

co

ncen

trat

ion

[vo

l.%]

O2, MP 1 CO2, MP 1

O2, MP 2 CO2, MP 2

0 5 10 15 20 25

Biological treatment time [weeks]

Figure 23: Relationship between oxygen content and carbon dioxide concentration

The diagram clearly shows how any increase in

the CO2 concentration is accompanied by a

corresponding decrease in the oxygen concen-

tration. Whenever the O2 concentration drops

below 5 % by volume, the CO2 level increases

markedly. Conversely, the CO2 level drops

below 5 % by volume as soon as the oxygen

content rises above 15 % by volume.

In the Phitsanulok pilot project, the gas compo-

sition within the heaps was monitored via an

extensive series of measurements. The parame-

ters of interest were oxygen, carbon dioxide and

methane. The readings were obtained via sam-

pling gauges installed at various points in the

heaps. The samples were drawn with the aid of

a vacuum tube and analyzed at the Asian Insti-

tute of Technology (AIT) in Bangkok. The fin-

dings were disparate. The first heaps showed

high methane concentrations (> 20 % by volu-

me) in combination with low oxygen levels

(< 5 % by volume) and relatively high carbon

dioxide levels. This was taken as an indication

of an-aerobic activity within the heap promoted

by a lack of oxygen. Most of the methane con-

centration readings correlated well with high

CO2 levels. The methane concentration hardly

ever rose above 10 % by volume if the oxygen

concentration was 10 % by volume or higher.

The third heap (heap C), which was situated on

an adequately sloped part of the old landfill,

displayed fewer high methane concentrations,

al-though some of the individual readings were

higher than 25 % by volume. There was a

remarkable, continuous increase in methane

concentration over time, and this was under-

stood as an indication of insufficient oxygen.

While the methane concentration never ex-

ceeded 10 % by volume during the first three

months, some monitoring points documented a

distinct rise in methane levels after about the

16th week of the composting process.

Visual inspection of the heaps revealed that the

points in question were very wet and fairly

blackened. These were points at which the pal-

lets had broken, and the bottoms of the heaps

were standing in water.

Data for the first five months of biological treat-

ment are available for the first of the heaps to be

set up in the designated waste treatment area

(heap D). Since less data were collected from

heap D than from heap C, no definite conclu-

sions can be drawn. However, it was noted that

the methane concentration increased during the

12th through 14th weeks of treatment and then

returned to levels below 10 % by volume by the

time of the last reading. An inspection of those

points once again disclosed that the pallets for-

ming the ventilating course had broken. Conse-

quently, pallets of higher quality are now being

used, and the new heaps are producing much

less methane. The lesson to be learned here is

that a well-prepared biotreatment area and care -

fully placed ventilating courses are two crucial

factors for the stability of the decomposition

process, and the results of their optimization will

be the subject of continued monitoring to valida-

te the observed developments.

Sector Project MBWT - Final Report

38

Figure 24: Waterlogged base of a heap showingevidence of anaerobic decomposition

The relevant evolution of methane may be attri-

butable to any of the following factors:

During the rainy season, the high initial

moisture level coupled with heavy precipi-

tation causes partial waterlogging of the

heap and, hence, formation of anaerobic

zones.

Sloppily installed, perhaps already broken,

pallets of poor quality allow waste to block

off the ventilating course and interrupt the

supply of air.

If the ground is not adequately reinforced

and becomes muddied by process water

and rainwater, the pallets will sink in and cut

off the supply of air.

If the waste contains a large share of plastic

bags and not much structural material, both

the air supply and the drainage of water can

be impeded at various points.

In Brazil, too, elevated methane concentrations

were noted at the beginning of the decomposi-

tion process. However, this was attributed to

methane emissions from the old landfill, on top

of which the heaps were standing. In the further

course of process implementation, there were

no more indications of elevated methane con-

centrations (odor, visual inspection, ...).

In Syria, oxygen concentration readings indica-

ted that the inferior structural properties of the

waste might cause a shortage of oxygen. To

verify this, the plastic bags were removed from

some of the waste, and the heaps' oxygen-sup-

ply situation was seen to improve substantially.

It was also recommended that extra structural

material be mixed into the waste in order to

promote better aeration.

39

20

18

16

14

12

10

8

6

4

2

0

Composition of gas in heaps C and D in Phitsanulok, ThailandSamples drawn Feb. 13, 2003

Gas

co

ncen

trat

ion

[vo

l.%]

O2 CO2 CH4

C2 C3 C4 C5 D1 D2 D3 D4 D5

Heap on old landfill Reinforced composting area with adequate

slope and pallet checks

Figure 25: Results of gas monitoring at heaps C and Don February 13, 2003, in Phitsanulok

4.2.5.4 Water content

The water balance of the heaps is also an

important criterion for optimal decomposition.

On the one hand, the microorganisms need

water for their metabolic processes, but on the

other hand high water contents promote the for-

mation of anaerobic cells as soon as the excess

water cannot be drained out of the heap. Hence

for the duration of the decomposition process,

the water content must be maintained within a

range that is amenable to aerobic decomposi-

tion. Consequently outdoor heaps have to be

watered during dry periods, but process water

can dribble out of the heaps during periods of

heavy rainfall. (The reader is referred to Chapter

4.2.6.4 with regard to the incidence and compo-

sition of process water.)

In Germany, initial water contents of 40 - 55

wt.% are regarded as favorable for extensive

decomposition processes. The water-retaining

capacity of the waste material is a relevant para-

meter. Since the starting material normally con-

tains relatively little water, an appropriate

amount is added at the beginning of biological

treatment. In the pilot project, however, the star-

ting material contained more water, because it

consisted largely of organic substances.

In Al-Salamieh, some 70 % to 80 % of the water

content of the input material is eventually lost to

evaporation and other factors. The Phitsanulok

trial showed water losses totaling approximately

50 %. (The reader is referred to Chapter 4.2.7.2

with regard to the mass balance.)

4.2.5.5 Solids and eluate analyses

Evaluating the biological efficiency of the

decomposition process necessitates an analysis

of the residual solids and eluate in the digested

material. This includes determining its total orga-

nic content (TOC) and its biological activity

(dynamic respiration activity level, AT 4, and gas

formation rate, GB21) in order to characterize

the remaining active organic substance. Analysis

of the pollutants, e.g. of heavy metals and or-

ganochlorine compounds in the eluate from the

solids, can provide information on the remaining

pollutant inventory, and hence on how much

pollution could result from emplacement of the

decomposed material.

The pilot project included various analyses of

solids and eluates. The following table compares

the results of the FABER-AMBRA® process in

Brazil after six months and after nine months of

biotreatment with the correlative values stated in

Germany's waste disposal directive on mechani-

cal-biological waste treatment facilities (AbfAblV,

App. 2), which must be adhered to in Germany

for proper landfilling of such material.

Sector Project MBWT - Final Report

40

Pilot project Water content [wt.%]

São Sebastião, Brazil > 60%

Phitsanulok, Thailand approx. 65%

Al-Salamieh, Syria 54% - 59%Table 6: Water content of waste inputs in the pilot projects

The results show that six months suffice for

most of the organic substance to decompose,

and that after nine months, the requirements of

Germany's waste disposal directive are reliably

satisfied. While some initial data on the results

of decomposition have been gathered in Phit-

sanulok, the findings indicate that the biological

activity can be expected to decline significantly

in the course of the process. Biotreatment-out-

put analyses are under way.

4.2.5.6 Results of composting trials in

Al-Salamieh, Syria

The Al-Salamieh field trials included broad-scale

tests and investigations on the treatment of

various input materials. In addition to the

mechanical-biological treatment of waste inputs,

the trials were also intended to investigate the

suitability of the process for producing market-

able compost. Both pure household waste and

separately collected and sorted biowaste were

test-composted.

The course of the various composting trials and

the quality of their outputs were characterized

on the basis of numerous tests and analyses,

the results of which show that a composting

time of 14 weeks is sufficient to obtain adequa-

tely mature finished compost. Even after a mere

6 to 8 weeks, the process reaches the maturity

of fresh compost.

41

Solids analysis Sample of 6-month-old comp.

Ignition loss [wt. % TS] 23,8

TOC [wt. % TS] 9,6

Respiration activity (AT4) [mg/kg TS] 5,4

Gas formation potential (GB21) [Nl/kgTS]

Eluate analysis

pH [-]

Electr. conductivity [µS/cm]

TOC [mg/l]

Ammonium-N [mg/l]

732

158

< 1,0

28,5

7,3

Sample of 9-month-old comp.

27,7

12,2

2,6

785

92

< 1,0

12

7,1

Correlation value(AbfAblV*, App. 2)

-

< 18

< 5

< 50.000

<250

< 200

< 20

5,5 - 13

COD [mg/l] 270

BOD5 [mg/l] 5

300

6

-

-

Table 7: Results of treated-waste analysis in São Sebastião 6

6 The laboratory analyses were conducted by the Leichtweiss Institute for Hydraulic Engineering at the Technical University of Braunschweig.

The findings in São Sebastião lead to the con-

clusion that a nine-month period of biological

treatment stabilizes the input material to such

an extent, that subsequent landfilling of the

residual waste would produce low emissions.

The compost substrates obtained via the

various forms of treatment all display good qua-

lity in terms of such value-defining physical and

chemical parameters as their nutrient contents,

salinity, pH and total organic content. However,

the benefits of collecting biowaste separately

are reflected by the significantly lower heavy

metal contents of the output.

In addition to documenting the suitability of the

process approach applied for mechanical-biolo-

gical waste treatment and obtaining high-quality

compost, the results also illuminate the benefits,

with respect to the quality of the finished com -

post, of either collecting biowaste separately or

pretreating the waste in a manner to achieve

similar results. Accordingly, the separate collec-

tion of biowaste would provide much-improved

conditions for an effective, more inexpensive

form of waste aftercare. However, the separate

collection of good-quality biowaste would most

likely have to be implemented on a step-by-step

basis and be correspondingly expensive.

Sector Project MBWT - Final Report

42

Table 8: Heavy-metal contents as a function of input material

mg/kgLead 117 105 114 122 118 117 150 120 150

mg/kgCadmium 0,1 0,1 0,1 0,2 0,1 0,1 1,5 3 5

mg/kgChromium - - - - - - 100 100 150

mg/kgCopper 96 82 90 87 72 65 100 150 250

mg/kgNickel 56 53 32 34 49 26 50 50 70

mg/kgMercury 2,3 2,1 1,90 1,90 2,10 0,89 1,00 1,50 3,00

mg/kgZinc 456 446 201 214 324 159 400 350

Compost samples

Separatebiowastecollection

Bundesgü-tegemein-

schaft*

Syrian

Uncomminuted hou-sehold waste

Sorted-out biowaste Comminu-ted house-hold waste Q. cat. 1 Q. cat. 2

500

in transgression of German targets* Targets of the German quality-compost association Bundesgütegemeinschaft Kompost e.V.

4.2.6 Emissions from MBWT

In Germany, very ambitious emission standards

have already been established for MBWT. In

most developing countries, though, it would not

be possible to meet similar targets quickly. The

waste disposal situation there can only be

improved gradually and in due time. Thus the

benchmark criterion for evaluating the emission

situation in the pilot projects is how much

improvement can be or has been achieved by

comparison with the initial waste-disposal situa-

tion.

4.2.6.1 Basic principles

The very nature and composition of waste per

se means that all forms of waste treatment will

inherently involve some sort of emissions, the

nature and extent of which will depend very

strongly on the chosen approach and the local

boundary conditions. The most important

MBWT emissions are listed below together with

various means of controlling them:

Leachate

Waste treatment produces process water, so

the biotreatment areas should be reinforced,

and the process water from biological treat-

ment needs to be collected and used for

watering the heaps, appropriately treated, or

disposed of. To the extent that an existing

landfill is equipped for leachate collection, it

may be expedient to put up the heaps for

simple biological treatment directly on top of

the landfill.

Odors, germs

The odor and gas emissions from simple

biotreatment heaps can be controlled by

covering the heaps with a course of screen-

ed, treated waste. Handling of the waste

releases germs into the environment, and

this can pose a health risk for the people

working at the landfill, though it has no

effect on areas situated further away.

Vermin

Table scraps and the like contained in hou-

sehold waste attract many different kinds of

animals that can contribute to the spread of

diseases and constitute a nuisance to local

residents. For simple processes, covering

the heaps is an effective means of keeping

animals away.

Noise

Comminutors, screeners, conveying and

ventilating equipment, etc. can be very noi-

sy, and both the operating personnel and

nearby residents are most strongly affected.

At a distance of 500 m or more, the noise

generated by MBWT equipment is not loud

enough to cause annoyance.

Another way to limit emissions is to take the

waste treatment operations indoors, where the

leachate and waste inputs can be collected and

treated in a manner to preclude most emissions.

However, this makes the facility correspondingly

more complicated and expensive in terms of

structures and machinery.

43

4.2.6.2 Odors

None of the pilot projects included any olfacto-

metric investigations as a basis for assessing

the odor situation. Nevertheless, both for the

waste treatment process itself and for subse-

quent landfilling of the residual waste, there can

be no doubt that the odor emissions are much

lower than if the untreated waste had simply

been dumped.

Most emissions in connection with MBWT occur

when the waste arrives, during its pretreatment,

and while the composting heaps are being put

up. In all pilot projects, the decomposition pro-

cess was seen to cause no odor-related pro-

blems. The coconut shells used as biofiltering

material in Phitsanulok served their purpose very

well. Such material itself occurs as a waste pro-

duct and is in abundant supply, free of charge.

Of course, to the extent that other kinds of

material are available (e.g. chopped garden trim-

mings), they can also be used.

Assuming that the decomposition process is

functioning properly, no annoying odor emis-

sions need be feared in connection with turning

or tearing down the heaps, or from emplacing

the pretreated waste at the landfill. The hoped-

for improvement in the odor situation at the

landfill thanks to waste pretreatment can gene-

rally be considered to have been fully achieved.

4.2.6.3 Hygiene

MBWT has the effect of extensively inactivating

or killing pathogenic microorganisms. Since it

was not possible to conduct any special hygiene

studies in connection with the pilot projects, the

hygienizing of the decomposing materials was

evaluated on the basis of the registered tempe-

rature profiles. In all field trials, the in-heap tem-

peratures remained above 55°C for several

weeks running (cf. Chapter 4.2.5.1). Accordingly,

an analysis of the time-history-of-temperature-

curves obtained in all pilot projects leads to the

conclusion that the waste material was hygieni-

zed by the decomposition process.

4.2.6.4 Process water

The quality and quantity of the emerging pro-

cess water depend on numerous different para-

meters, e.g. the composition and structure of

the waste, the height of the heaps, the tempera-

ture, the rates of evaporation and precipitation,

and the form of treatment employed. All three

pilot projects included examination of the pro-

cess water. Hence the results shown below can-

not be generalized, but apply only under the

given set of pilot-project boundary conditions.

Sector Project MBWT - Final Report

44

Figure 26: Coconut-shell biofilter at the Phitsanulok MBWT facility

For the first few days after the heaps are put up,

they may release what is referred to as water of

consolidation. In Al-Salamieh, the water regi-

mens of the various heaps were monitored and

analyzed in the course of the composting pro-

cess. Thanks to the cover, the only process

water to appear was this water of consolidation,

i.e. some 4 - 6 l of process water per Mg waste

emerged from the covered heaps during the first

few days of the process. Table 9, below, shows

the composition of the process water.

This process water is so polluted, that the base

of the biotreatment area will need a liner. Co-

vered and indoor heaps produce so little pro-

cess water during the decomposition process

that there is no problem in collecting and retur-

ning.

For uncovered, outdoor heaps, however, the

amount of process water produced during the

first few days of decomposition depends on the

duration and intensity of precipitation. Biotreat-

ment heaps can absorb small amounts of rain,

but the more rain falls, the less the heap can

store.

In São Sebastião, the process water emerging

from a commercial-scale test heap (230 m²) was

monitored with regard to quality and quantity.

The heap was put up on a specially sealed field.

45

Unit

Water content of input %

Process water fraction l/Mg Solids

pH -

COD

BOD5

Conductivity

Ammonium

mg/l

mS/cm

mg/l

mg/l

Heap of manuallysorted biowaste

58,5

4,2

7,4

12.230

15,2

145,0

36.780

Heap of mixed and commi-nuted household waste

57,1

3,8

6,8

6.580

14,9

144,0

24.750

Nitrate mg/l 0,7 0,8

Table 9: Quantity and quality of process water from biotreatment windrows in the Al-Salamieh scale-model trial

Sediment washout had very detrimental effects

on the operability of the analytical setup, so the

results of quantitative monitoring are only relia-

ble for the very brief period between May 15

and June 3, 2001. Some 98 l/m² of rain fell

during that period. Projected over the full area,

that results in 22,540 l of rainfall, while 7,245 l of

process water emerged from the test heap.

Figure 28 illustrates the course of the cumulative

curves over the period in question.

Process water began to emerge from the heap

about 2 days after the first rain. In the case

under review, some 30 % of the overall precipi-

tation eventually reappeared in the form of pro-

cess water.

The quality of the process water from the test

heaps in Rio de Janeiro and São Sebastião was

monitored over a prolonged period of time. Figu-

re 29 reflects the results of analysis.

Sector Project MBWT - Final Report

46

25.000

20.000

15.000

10.000

5.000

0

Sao Sebastiao projectTest heap

Vol

ume

(l)

Precipitation Process water

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Time (d)

Figure 28: Cumulative curves showing the precipitation onto and the processwater volume emerging from the test heap in São Sebastião

Figure 27: Test heap in São Sebastião

These results show that, during the first four

months of biological treatment, the process

water burden remains at levels that do not per-

mit its infiltration into the ground or its discharge

into an effluent stream. After that, the process

water burden gradually decreases, but never to

the point of negligibility any time before the end

of biological treatment. Consequently, the

decomposition process should always take pla-

ce on sealed surfaces.

Both in São Sebastião and in Phitsanulok, the

accumulated process water is used for watering

the heaps during dry spells. It is assumed in São

Sebastião that approximately one-half of the

incidental process water can be reused. The

remainder requires wastewater treatment.

47

65.000

60.000

55.000

50.000

45.000

40.000

35.000

30.000

25.000

20.000

15.000

10.000

5.000

0

Rio de Janeiro and Sao Sebastiao pilot projectsProcess water burden

mg/

l

0 50 100 150 200 250 300 350 400 450

Treatment time (d)

COD Rio

BOD5 Rio

COD Sao Sebastiao

BOD5 Sao Sebastiao

Figure 29: Quality of process water from test heaps in Rio de Janeiro and São Sebastião

Figure 30: Process water seeping out from the base of a heap in São Sebastião

4.2.6.5 Methane emissions

When untreated waste is landfilled, it generates

landfill gas. In its stable methane phase, landfill

gas consists of approximately 60 % methane

and 40 % carbon dioxide. The decomposition

processes employed in the pilot projects are

aerobic processes that release only minimal

amounts of methane, as long as the process

proceeds in its proper fashion. However, aerobic

decomposition can only be assured if the heap

receives a constant and adequate supply of

oxygen. In cases of insufficient aeration/ventila-

tion, anaerobic conditions will arise at various

points within the heap. This is evidenced by the

appearance of methane in the specimens when

the gas is analyzed. If the aerating effect is ade-

quate, the methane content of the analyzed spe-

cimens must consistently remain below 1 % by

volume. Methane contents between 1 % and

5 % indicate minor, insignificant disturbances

affecting the decomposition process. Methane

contents in excess of 5 % by volume, however,

indicate a seriously defective process, if they

last for any substantial length of time.

Thus with regard to the emission of climate-rele-

vant off-gases, MBWT represents a considerable

improvement over conventional landfilling practi-

ces. Overall, mechanical-biological waste treat-

ment reduces the amount of gas that would be

produced under normal-landfill conditions by

more than 90 % [5].

The methane emission levels measured during

the pilot projects were discussed in Chapter

4.2.5.3. Aerobic decomposition can only be

expected to make a positive contribution toward

climate protection if the heaps are always ade-

quately aerated, and regular gas monitoring is

necessary in order to detect anaerobic activity at

an early stage. Olfactory sampling and visual

inspections can only reveal deficits if the metha-

ne concentration is already quite high.

4.2.7 Disposal of pretreated waste

to the landfill

The subject waste-treatment concept does not

inertize the material to the point of making it

absolutely unalterable in the biological, chemical

and physical sense. Instead, the process only

stabilizes the waste input, and there will always

be some amount of residual waste that has to

be dumped. On the other hand, a landfill full of

MBWT-output material has little similarity with a

conventional landfill for untreated waste. Both

the technology involved and the environmental

impacts differ widely.

4.2.7.1 Fundamental considerations

When evaluating the performance of a mechani-

cal-biological waste treatment facility, one must

bear in mind that the properties of the treated

waste will depend on the process employed, the

length of treatment, the varieties of material

extracted, and the local boundary conditions. In

any case, the amount of biodegradable substan-

ce remaining behind in the residual waste will

have been substantially reduced. That, in turn,

means a decisive decrease in biological decom-

position processes within the landfill. The water

content will be lower, the mean particle size

smaller, and the pretreated material significantly

more homogeneous.

Sector Project MBWT - Final Report

48

For the evaluation of an MBWT facility, the way

it affects the present and future landfill situation

is of major importance. Within the scope of the

pilot projects it was not possible to evaluate

any longterm changes, because many such

effects take a number of years to become

apparent. However, some initial findings regar-

ding the ultimate disposal of pretreated waste

were secured both in São Sebastião and in

Phitsanulok.

Consequently, the situation in and around the

landfill can be expected to improve in the follo-

wing ways:

Less waste for ultimate disposal

The combination of biological degradation of

organic substance and possible extraction of

certain material varieties at the mechanical

conditioning stage markedly reduces the

residual quantity of waste to be disposed of.

The extent of the mass (or bulk) reduction

taking place in the course of biological treat-

ment results from the decrease in water con-

tent and total solids. The weight reduction

resulting from the loss of water is the diffe-

rence between the water content of the

input material and that of the end product.

The decrease in total solids, in turn,

depends on how much organic substance

(total organic solids) is degraded, and on its

percentage share in the total solids content.

Biodegradation proceeds at different intensi-

ty levels, depending on which natural sub-

stances predominate.

Firstly, the readily degradable components

decompose within a relatively short time,

while the substances that are more difficult

to break down become more concentrated

as the process progresses and the degrada-

tion rate slows down. Once biodegradation

of the easily degradable substances is com -

plete, the total organic content will remain

essentially unchanged up to the end of the

process. Within certain limits, the loss of

mass can be manipulated by the process

engineering invested. The extent of mass

reduction is, as a rule, largely dependent on

the length of the decomposition process and

on the amount of work and material that was

invested in the waste treatment.

Compaction

Thanks to pretreatment, residual waste

emplaced in thin layers can be compacted

to a much higher in situ density than can

waste in conventional landfills, and the land-

fill body sustaining much less settling after-

ward. Figure 31 compares various densities

of compaction, as ascertained for different

forms of waste pretreatment in Germany.

49

1,8

1,6

1,4

1,2

1,0

0,8

0,6

0,4

0,2

0

0,56 0,560,68 0,67 0,67

0,820,76 0,76

1,11

0,87

1,02

1,25

0,97

1,14

1,56

Co

mp

act.

den

sity

ρ dry

[t M

S/m

3] ρ

dry

ρ dry

*[t

TS

/m3]

Absolute density of compaction (dry)

Relative density of compaction (dry) based on

waste bulk prior to treatment

Density of compaction (moist)

BS I BS II BS III BS IV WH V*(Standard landfill) (Comminuted + (Comminuted, (Comminuted, (Comminuted,

thin layer) homogenized homogenized, homogenized, + thin layer) decomposed decomposed

+ thin layer) + thin layer)

Figure 31: Densities of compaction with and without pretreatment [6]

* other landfill siteMS = moist substanceTS = total solids

Less use of topsoil as daily cover

Many landfill areas are covered with topsoil

at the end of each day as a means of avoi-

ding waste exposure and in order to make

the surface traversable. However, the topsoil

ends up occupying a substantial share of

the landfill volume. Landfills reserved for

waste that has undergone mechanical-biolo-

gical pretreatment require no daily covers of

topsoil.

Longer useful life of landfill

The aforementioned factors help prolong a

landfill's useful life by a large measure.

Depending on the initial situation and the

MBWT process employed, the landfill's

useful life can be at least doubled.

Landfill leachate

In the medium term, the quality of leachate

can be expected to improve markedly, one

reason being that the phases of biological

degradation causing the most relevant orga-

nic pollution of the leachate take place prior

to deposition of the residual waste. Hence

the leachate burden, in terms of TOC and

COD, gradually decreases by as much as

90 %. On the other hand, the leachate also

picks up pollutants via extraction processes.

In the course of time, though, the compac-

ted waste becomes gradually less perme-

able, so less and less water can penetrate

into the landfill body, and accordingly less

leachate is produced.

Gas

MBWT reduces landfill gas production very

considerably. The actual extent of this

reduction depends on how much time the

material had to decompose. Decomposing

times of 20 weeks and longer can cut as

much as 95 % off of the residual gas

potential.

Landfill fires

Mechanical-biological waste treatment mar-

kedly reduces the danger of landfill fires.

Indeed, if the high-energy fraction is separa-

ted out, there will be no danger at all of

landfill fires.

MBWT improves the waste's placement and in-

dump behavior, while reducing its ultimate-

disposal volume. Nevertheless, no amount of

pretreatment can suffice to rule out the possibili-

ty of the landfill causing some environmental

pollution. For example, MBWT can do little to

break down any inorganic pollutants which may

be contained in the waste inputs, so such sub-

stances can continue to pollute the groundwater

after emplacement. Hence in professional cir-

cles, pretreatment is regarded as a supplemen-

tary measure, by means of which the environ-

mental health hazards emanating from landfills

can be mitigated. It has no effect on the stan-

dards to be met by landfills in any given country,

i.e. no such standards can be relaxed in advan-

ce because of MBWT.

On a case-by-case basis, though, the achieva-

ble results of waste treatment may be examined

with regard to the possibility or necessity of

gas collection or passive venting through a

surface filter,

dispensing with a surface cap for high den-

sities of compaction and low permeability,

and adapting the treatment of leachate to

allow for lower pollution levels and smaller

quantities.

Sector Project MBWT - Final Report

50

4.2.7.2 Mass reduction determined in

the pilot projects

The loss of mass (or bulk) due to

aerobic decomposition and the

remaining mass of organic material

in the product of biotreatment were

investigated as part of the Al-Sala-

mieh field trials. The moist mass

was weighed at the beginning and

end of the composting process,

and the water content of lots weig-

hing roughly 20 kg each was deter-

mined. The total organic content

was ascertained via the ignition loss.

In Phitsanulok, the loss of mass was determined

by weighing the waste input prior to mechanical

conditioning and after biological treatment. The

findings show that mechanical-biological waste

treatment reduced the moist mass by 53 %,

mainly in the form of lost water. At 19.2 %, the

organic decomposition rate is comparable to

data found in pertinent literature. The results

could probably be improved somewhat by opti-

mizing the MBWT processes beyond what was

achievable during the early phase of the Phit-

sanulok project. Figure 33 summarizes the

results.

51

1.600

1.400

1.200

1.000

800

600

400

200

0

577 465

211

938

Mas

s (M

g)

Phitsanulok project Mass reduction

Input to heaps A + B Output to heaps A + B

H2O TS

53 % reduction MS

19 % reduction TS

Duration of biotreatm. d

Input treatmentwater content of input

TOC of input

%%%

Output treatmentwater content of output

TOC of output

%%%

Loss of mass %

Hand-sorted bio-waste

100

10058,541,5

38,910,528,4

61,1

Mixed, commin-uted waste

110

10057,142,9

34,510,024,5

65,5

Figure 32: Emplacement of pretreated waste in São Sebastião

Table 10: Mass reduction through biotreatment in the Al-Salamieh, Syria, scale-model trials

Figure 33: Mass reduction in the pilot phase of MBWT in PhitsanulokMS = moist substanceTS = total solids

4.2.7.3 Emplacement trials in

the pilot projects

The main objective of landfilling is to make opti-

mal use of the - expensive - available emplace-

ment volume. Consequently, commercial-scale

compaction tests designed to ascertain the

maximum achievable density of compaction for

residual waste from a mechanical-biological

waste treatment facility by means of the pre-exi-

sting landfill compactor were run at the Phit-

sanulok landfill. The compactor in question

weighs 20 tons and is 3 m wide. A test field

measuring 15 x 15 m was staked out on undis-

turbed soil at the Phitsanulok landfill site.

Sector Project MBWT - Final Report

52

Turning area

15 m

15 m

Top of emplaced waste

Formation levelWaste

3,0 m > 7,95 m 3,0 m

Test-field Formation

Figure 34: Test-field dimensions for the commercial-scale compaction trial (Deutsche Gesell -schaft für Geotechnik e.V., Recommendation E 24, as modified)

Figure 35: Dry-season emplacement trial for pretreatedwaste at the Phitsanulok landfill in Thailand

The waste to be emplaced was weighed, spread

out across the test field by an excavator in lay-

ers approximately 30 cm thick, with each layer

being compacted in five passes. A tachymeter

was used to determine the volume of the empla-

ced waste.

The Phitsanulok landfill's 20-ton compactor

compressed the unscreened waste to an abso-

lute density of 1.10 Mg MS/m³ or 0.76 Mg

TS/m³. In Brazil, where a 30-ton compactor was

used, compaction densities of 1.1 - 1.4 Mg/m³

were measured in application of the volume-

replacement method.

The densities determined during the emplace-

ment trials were arrived at under dry weather

conditions. The emplacement of pretreated

waste is also unproblematic with regard to the

ground's load-carrying capacity and traver-

sability, as long as the weather stays dry.

However, past experience in Germany and São

Sebastião shows that the incorporation of pre-

treated waste becomes increasingly difficult with

increasing precipitation. As it absorbs water, the

waste becomes pasty and eventually impossible

to drive over or compact. If possible, then, no

waste should be emplaced during rainy periods.

Of course, that would be very difficult to put into

practice in regions with high precipitation rates.

There are various technical options for improving

the emplacement situation during rainy seasons,

but the scope of the pilot project did not allow

their testing.

53

1,2

1,0

0,8

0,6

0,4

0,2

00,17

0,760,53

1,1

(Mg

/m3 )

Phitsanulok project

Heaps A + B Density of compaction

Dry density

Moist density

Figure 36: Comparison of in-heap densities and achieved landfill compaction densities

4.2.7.4 Landfill leachate in São Sebastião

A landfill reserved for pretreated waste has been

in operation in São Sebastião since the fall of

2002. The leachate is collected and routinely

sampled to keep tabs on the typical parameters

shown in Figure 37.

These investigations confirm expectations to the

effect that pretreatment definitely improves the

quality of landfill leachate. However, long-term

studies would be necessary to arrive at any reli-

able information on leachate incidence and

emburdenment.

4.2.8 Costs

4.2.8.1 Costing principles

To assess the cost of waste treatment, one must

customarily weigh out the capital investment,

the cost of operation, and the revenues. Having

obtained that information, one can calculate the

annual costs and the specific cost per ton of

handled waste. The annual costs, i.e. those that

recur each year, comprise the following items:

annual capital (servicing) costs (e.g. initial

cost of equipment and construction, real

estate, etc.)

throughput, independent (nonvariable) ope-

rating costs (e.g. insurance premiums, lease

payments, etc.)

Sector Project MBWT - Final Report

54

2.200

2.000

1.800

1.600

1.400

1.200

1.000

800

600

400

200

0

MBWT landfill in Sao SebastiaoLeachate burden

mg/

l

07/23/02 08/22/02 09/21/02 10/21/02 11/20/02 12/20/02 01/19/03 02/18/03

Time

1st emplacement in July 2002

COD BOD5 NH4-N

2nd emplacement in December 2002

Figure 37: Leachate burden at the MBWT landfill inSão Sebastião

throughput-dependent operating costs

(e.g. electricity, fuel, residual-waste dis-

posal, etc.)

returns (e.g. proceeds from the sale of

recyclables)

Since there are so many variants to choose

from, the cost of mechanical-biological waste

treatment can vary widely. Other specific-cost

factors include the plant throughput rate (mean-

ing that the specific costs decline with increa-

sing throughput rate) and the capacity utilization

rate (meaning that the specific costs rise with

decreasing capacity utilization rate). However,

these costs do not transfer readily from one

country to the next, because:

the expenditures for personnel, construction

and energy, in addition to the customs and

tax laws, vary widely from country to country

and from region to region,

country-specific standards for emission con-

trol, wastewater purification, monitoring,

etc., exert a major influence on costs,

fluctuating exchange rates can alter the cost

of capital goods and operating supplies.

Hence the cost of personnel accounts for a lar-

ge percentage of the overall cost at extensive

facilities in countries with high wages. Conver-

sely, in countries with low labor costs, the per-

sonnel costs account for a much lower percen-

tage of the overall cost. At intensive facilities,

the cost of labor accounts for a lower percenta-

ge of the overall cost, while customs regulations

and conditions of supply and warranty are much

more important.

If the results of cost determination are to be reli-

able, the boundary conditions of each concrete

case must also be taken into consideration. One

should also keep in mind that considering the

cost of waste treatment only could lead to erro-

neous conclusions. After all, mechanical-biologi-

cal waste treatment influences all the other

aspects of waste management, too, so the enti-

re disposal system must be accounted for in any

proper cost assessment. Only then can the

additional costs of mechanical-biological waste

treatment be properly compared with and

weighed against corresponding cost reductions,

particularly with regard to final disposal

(cf. Chapter 4.2.8.3).

4.2.8.2 Examples of costs incurred in

the pilot projects

The cost calculations for the pilot projects in

Brazil and Thailand, as well as for the scale-

model trial in Syria, are presented and discussed

below. The cost of waste treatment in Brazil can

be determined fairly accurately, because the

project was of long duration, and normal opera-

tion has already commenced. The project in

Thailand is still in its pilot phase, so no complete

sets of data are available, especially not for the

variable costs of operation. However, the same

process with the same procedures and the

same equipment can be employed for normal

operations here, too. Moreover, the availability of

extensive pertinent analyses and calculating

models makes it possible to at least determine

the general orientation.

By reason of the differences in process techno-

logy, the project in Syria is interesting for com-

parison purposes. However, the cost estimates

for Syria are not unconditionally comparable

with those of the other two projects because

they are based on the experience drawn from

and the assumptions made in the (220-ton) field

trial. These same assumptions have not yet

been verified in any large-scale field trial.

The basic prerequisites for calculating project

costs differ from case to case, sometimes sub-

stantially. For example, no interest rates were

included in the calculations for Phitsanulok,

because that would have run counter to the nor-

mal investment financing practices of Thai com -

munities.

55

With a view to rendering the cost calculations

mutually comparable as regards process-speci-

fic and conceptual differences, the pure cost of

treatment (MBWT) was figured on the basis of

available data, while the cost of waste collec-

tion, delivery and subsequent disposal were left

out of the sample calculations, even though they

would have been applicable. Hence the costs

considered covered the preparation of MBWT

areas, the technical equipment, maintenance

and repair costs, and the collection and treat-

ment of any incidental leachate.

The computations are also based on numerous

assumptions designed to allow the estimation of

unknown costs and to make project-specific

calculatory approaches mutually comparable.

Hence the stated figures are suitable for use in

documenting the various (project- and country-

specific) factors of influence and for illuminating

the scale of the anticipated costs.

Costs resulting from the company's cooperative

efforts in the respective countries (e.g. license

fees, training, etc.) have been omitted, as have

the outlays for land acquisition and planning.

The specifics of the individual projects with

regard to cost determination are listed below:

Brazil

Ample spare waste-treatment capacity is

needed here, because the area hosts nume-

rous tourists during the main traveling sea-

son. For four months each year nearly twice

as much landfill labor and operating supplies

are needed as during the rest of the year.

The landfill serves a very large area, and

some of the waste has to be hauled in from

as far away as 100 km. Consequently, the

cost of waste transport is accordingly high

and must be allowed for in the waste

management concept.

Decomposing heaps that cannot be put up

on the old landfill require some form of rein-

forced profiling. These areas are presently

being prepared by means of a bulldozer /

grader and an HDPE tarpaulin (geomembra-

ne lining). A lump sum per square meter was

taken into consideration as the cost of treat-

ment-area preparation.

Due to the large distance between the land

fill and the wastewater treatment plant, the

cost of leachate disposal is relatively high.

On the other hand, no other special equip-

ment is needed directly at the landfill.

The planned use of green waste and pru-

nings as structural material or as a biofilter

was not allowed for in the calculations.

The heaps are watered by means of gasoli-

ne-engine-driven pumps feeding into a sim-

ple system of hoses and sprinklers. These

costs are also figured into the variable ope-

rating costs as a lump-sum item.

Sector Project MBWT - Final Report

56

Thailand

By reason of Thailand's public-sector invest-

ment policy, no interest rates have to be

accounted for, because all investments are

directly financed. However, in the interest of

comparability, a 6 % capital interest rate

was figured into the calculations.

The biotreatment area was prepared accor-

ding to a relatively elaborate technique cor-

responding to the base of the landfill body.

The cost of consumables, maintenance and

repairs can only be estimated, because the

plant has not yet entered its regular opera-

tion phase at nominal throughput. The esti-

mates were made on the basis of facts alre -

ady established.

The treatment of process water has been

integrated into the treatment of leachate, so

the cost of leachate treatment is accounted

for here as a proportion of the overall invest-

ment costs. No operating cost data are avai-

lable.

Watering is effected via a pump and sprink-

ler system. Again, no operating cost data are

available.

Under the present circumstances, the mate-

rial used for the biofilter is obtained free of

cost, i.e. producers deliver it to the landfill

free of charge.

Syria

The postulated costs are in line with the

data gathered in the course of the field trial.

They are not based on empirical data or on

figures deriving from actual operation of a

plant. Consequently, these costs must be

regarded as the minimal process costs wit-

hin the local context. Hence this project

does not lend itself well to comparison with

others. Especially with regard to operating

costs, no reliable information is available.

Since the design of the plant is not yet com-

plete, the technical equipment has not yet

been outlined or sized. For purposes of

comparison, an equipment fleet consisting

of a homogenizing drum, a screener, a wheel

loader and a truck was postulated.

Prices cited by local manufacturers were

assumed here as the cost of procurement

for a homogenizing drum and screener nee-

ded for conditioning the waste input. Consi-

dering the empirical data collected in other

projects, the suitability of the equipment,

and hence of its durability and depreciation

expenses, are somewhat questionable.

Thanks to the fact that the composting time

is shorter than for passively aerated heaps,

the treatment area is correspondingly smal-

ler.

The heaps require no watering.

The postulated investment costs plus main-

tenance and repair expenditures also cover

the cost of the biofilter / seal / cover.

All costs are stated as specific costs in relation

to the plant's projected annual throughput.

57

Sector Project MBWT - Final Report

58

Table 11: Comparison of specific costs in the pilot projects

Pos. Project Sao Sebastiao, Brazil

Data basis Normal operation

CharacterizationFaber-Ambra, normal ope-ration for all waste inputs, 9 months of decomposition

Phitsanulok, Thailand Al- Salamieh, Syria

Pilot-scale field trial Scale-model trial

Faber-Ambra, postulatedfor target throughput,9 months of decomposi-tion

Gore laminate process, sta-tic, actively aerated heaps,3 to 4 months of decompo-sition

Notes No plans for screeningdrum or comminution ofgreen waste; no landfilling

Operating costs indetermi-nate for watering and lea-chate disposal

Costs roughly calculatedand only conditionally com-parable; suitability of localequipment requires furtherstudy

Annual throughput 30.000 Mg 32.850* Mg 20.000* Mg

Specific costs Specific costs Specific costs

Designation [€/Mg Input] [€/Mg Input] [€/Mg Input]

1. Investment costs 3,8 € 5,0 € 6,8 €

1.1 Buildings + infrastructure 0,4 € 2,4 € 0,1 €

1.2. Technical equipment 3,4 € 2,6 € 6,7 €

1.2.1. Comminution homogenization 1,9 € 1,4 € 0,2 €

1.2.2. Excav., wheel loader transport 1,5 € 0,9 € 2,1 €

1.2.3. Ventilation / cover / watering -- € 0,3 € 4,2 €

1.2.4. Leachate collection and treatment -- € 0,1 € 0,2 €

2. Wages and salaries 1,7 € 0,8 € 1,1 €

3. Maintenance and repair 2,2 € 1,6 € 2,8 €

4. Var. operating costs 7,1 € 3,3 € 1,1 €

4.1 Fuel/lubricants 2,4 € 0,7 € 1,0 €

4.2 Ventilation 1,0 € 2,6 € < 0,1 €

4.3 Watering 0,3 € -- € -- €

4.4 Biofilter/cover/seal 2,5 € -- € -- €

4.5 Leachate disposal 0,9 € -- € < 0,1 €

Total 15 € 11 € 12 €

Allowance for cost risks -- € + 2,1 € + 3,5 €

* Planned/projected plant throughput** The costs of leachate collection and of the leachate pond are included in the construction costs (Item 1.1)

**

The following assumptions were made in esti-

mating the existing uncertainties (margin of safe-

ty):

Phitsanulok

Since the MBWT facility is still in its pilot-scale

field trial phase (30 Mg/d), and since some of

the costs can only be estimated, a 20 % safety

allowance was added to the overall costs to

account for unforeseen items.

Al-Salamieh

Cost basis: comminution / homogenization

at German rates (EUR 175,000 instead of

EUR 25,000 for the homogenizing drum and

rotary screener)

Additional personnel required (+25%)

Higher fuel / energy consumption (+25%)

The following diagram illustrates the cost com -

position.

59

18

16

14

12

10

8

6

4

2

0

3€

7€

2€

2€

4€

2€

2€

1€

5€

4€

1€

3€

1€

7€

Sp

ecifi

c co

st o

f M

BW

T [

EU

R/M

g]

Pilot-project cost calculations vs. cost estimate for Al-Salamieh, Syria

São Sebastião , Brazil Phitsanulok, Thailand Al-Salamieh, Syria

Investment costs Maintenance & repair Wages & salaries

Variable operation costs Safety allowance for cost estimate

Figure 38: Comparison of pilot-project cost calculations (specific costs in EUR/Mg)

When interpreting the above figures it is impor-

tant to keep in mind that the Al-Salamieh project

is not directly comparable with the other pro-

jects, because the plant is still at the planning

phase and no practical experience has been

gained to date.

The various calculations yield overall costs of

mutually similar proportions. The specific invest-

ment costs of the process employed in Syria are

approximately 30 % higher than those of the

FABER-AMBRA® process, because the techni-

cal equipment fleet is more expensive. Conspi-

cuously, the operating costs are roughly twice

as high in Brazil as they are in Thailand and

Syria. This is partially attributable to differences

in the local situation (e.g. higher waste incidence

during the tourist season, high personnel costs

and expensive biofilter material), but probably

also to the greater reliability of the Brazilian

data.

The variable operating costs of the FABER-

AMBRA® process were essentially defined by

the cost of the aerating course and the biofilter.

The costs of fuel and lubricants for the projects

in Thailand and Syria were extrapolated from the

current consumption rates and, respectively,

estimated on the basis of the mechanical equip -

ment used. Likewise, presently available infor-

mation does not allow quantification of the

watering and leachate-treatment costs in Thai-

land. The energy consumption rates assumed

for ventilation in the Syrian project are very low.

4.2.8.3 Effects of MBWT on the cost of

waste disposal

The MBWT costs described above in Chapter

4.2.8.2 at least partially offset the net cost of

waste disposal. The cost-related effects of

MBWT were explained in Chapter 4.2.7. The

costs of the various residual-waste treatment

alternatives were estimated within the scope of

a comprehensive cost investigation for the pro-

ject in Phitsanulok, Thailand. The effects of

MBWT on the cost of waste disposal were des-

cribed for the following set of boundary condi-

tions:

Pure landfilling: continuation of landfill ope-

rations (approx. 90 Mg/d) in the present

form; optimization of placement practice.

MBWT / landfill: combination of MBWT (with

all incoming waste, i.e. approx. 90 Mg/d,

being given the full treatment) and subse-

quent landfilling (thin-layer emplacement),

which prolongs the useful life of the landfill,

causes less leachate to be produced, and

means that the landfill requires less

aftercare.

Sector Project MBWT - Final Report

60

As the two columns in Figure 39 plainly show,

pretreatment reduces the specific landfilling

costs by some 50 %. This extensively offsets

the cost of MBWT. Most of the gain is attributa-

ble to prolongation of the landfill's useful life.

4.2.9 Informal sector

In many countries, all or most waste is proces-

sed by the informal sector. The levels of inter-

vention of the informal sector are illustrated in

Figure 40.

61

16

14

12

10

8

6

4

2

0

Sp

ezifi

c c

ost

s [€

/Mg

]

Comparison of specific landfilling costs with and without MBWT

Landfill MBWT/landfill

Approx. 50% lower

landfilling costs

Cost of landfill aftercare

Cost of landfill operation

landfill investment costs

Recycling material

Organic materialResid wasteTotal waste

Intervention by informal sector

Wasteincidence

Putting outfor collection

collection(mixed)

Reloading Hauling Industry

Separationby producer

collection(seperate)

Sorting

Composting

Incineration

MBWT

Agriculture

Disposal

Figure 39: Comparison of specific landfilling costs in Phitsanulok with and without MBWT (specific costs in EUR/Mg)

Figure 40: Informal-sector intervention in the flow of household waste

(c) Wehenpohl / A.L.F. dos Santos; 01/2000

The informal sector in waste management does

not consist solely of people with low incomes,

but also includes, in various numbers, all clas-

ses: for instance intermediate dealers (brokers),

owners / proprietors of (further-processing) recy-

cling businesses, etc. The introduction of MBWT

in combination with controlled landfilling

amounts to a partial reorganization of the waste-

management sector, and any changes effected

can alter the boundary conditions for the infor-

mal sector.

With a view to preventing negative impacts, and

perhaps even to offering the sector some work-

able alternatives, submeasures designed to pro-

mote integration of the informal sector were built

into the sector project. In Brazil, for example,

where the informal sector is traditionally very

prominent, the sector project provided support

to another project being implemented in parallel

with the MBWT pilot project. This project was

called "Formalization of the Informal Waste-

management Sector in São Sebastião and Ilha-

bela". The project, termed Cooperativa de Tria-

dores (cooperative for the recovery of recycla-

bles), sponsored by the São Sebastião munici-

pal administration, is geared to reducing the

inflow of waste to the local landfill and to the

pursuit of additional objectives in the areas of

social and environmental policy. For example, a

program of separate collection and subsequent

sorting of waste and recyclables is intended to

create income opportunities for the poor and

needy. The program, it is hoped, will offer that

group some future-oriented, economically feasi-

ble perspectives. Simultaneously, by esta-

blishing the cooperative for the utilization and

sale of recyclables, the authorities hoped to

involve people more in waste management. The

relevant skills of the individuals concerned were

systematically improved via training and motiva-

tion measures. One of the criteria for participa-

ting in the program was that adults take part in

the training.

Results:

The group was officially registered as a co-

operative (in North-Center and Ilhabela).

The monthly income of the members increa-

sed more than twofold.

The amount of recycled waste was increa-

sed substantially as the members became

familiar with methods that increased the effi-

ciency of their work and improved the

results of dedicated sorting.

Some of the recyclables were sold directly

to the processing industry without the need

for brokers, so the revenues were much hig-

her.

Sector Project MBWT - Final Report

62

Figure 41: Members of the Ilhabela Cooperativeat work sorting recyclables

The success of these measures greatly increa-

sed the members' motivation and improved their

standing with the municipal authorities.

The following recommendations and conclu-

sions can be drawn from the results of support

given in São Sebastião and Ilhabela:

Some of the people populating the various

parts of the informal waste-management sec-

tor cannot be successfully integrated into more

formal structures, because, among other fac-

tors, some are alcoholics and/or drug addicts,

and some are unable to subordinate themsel-

ves to regular work regimens.

In São Sebastião, some people who had

never before worked in the waste-management

sector were successfully integrated into waste-

sorting processes, despite the fact that this is

generally viewed as a repulsive field of work.

Experience shows that the chance to earn

one to three times the minimum wage working

in this sector can attract people from low-inco-

me brackets who have not previously worked

in the sector.

Municipal waste management is a communi-

ty task. As such, the community's consent is

required for integrating these people without

adopting a paternalistic stance.

The development of formal structures requi-

res the support and backstopping of external

specialists (social workers, accountants,

lawyers, waste-management technicians, etc.).

Two to three years of support will probably

be necessary.

Granting small-scale loans to such groups

can have a supportive effect but needs to be

considered on a case-by-case basis and

should not be allowed to become too much

of a burden on the group. Experience in

other areas shows that small, short-term

loans are often more appropriate than large,

long-term loans, because it is easier to learn

how to deal with them. Credit organizations

should be advised of this.

63

5.1 Conclusions Drawn from the Pilot

Projects

As the pilot-project examples show, mecha-

nical-biological waste treatment can be

successfully implemented in developing and

threshold countries. In the pilot projects featured

here, the biological decomposition processes

employed yielded good results and hence achie-

ved the primary goal of improving the in-dump

behavior of the residual waste. In São Se-

bastião, MBWT has already radically improved

the landfill situation and become a fixed compo-

nent of the city's waste-disposal concept.

The MBWT version tested in Syria, i.e. with

cover and forced ventilation, is a more elaborate

technology, but it amounts to a very promising

approach for areas with little water as well as for

areas with high rates of precipitation. The next

step will be to engage in commercial-scale

application of the results of the field trial. If the

production of high-quality, marketable compost

in Al-Salamieh is to be assured in the long term,

the separate collection of organic waste will

have to be expanded step by step.

The specific costs of pretreatment determined in

the pilot projects range between 11 and 15

EUR/Mg input. However, if the economizing

effect that MBWT has on landfilling operations is

subtracted from the costs of MBWT, the remai-

ning specific costs drop to just a few Euros by

comparison with those of landfilling waste

without pretreatment. Indeed, in Phitsanulok, the

cost of waste disposal with and without MBWT

is practically identical. Moreover, the combina-

tion of mass reduction and improved compressi-

bility achieved via MBWT can lengthen a landfil-

l's useful life several times over. On the other

hand, even Germany's time-tested "simple pro-

cesses" have to be accommodated to the local

boundary conditions prevailing in other countries

in order to achieve the desired results. In that

sense, the "simple processes" used in the pilot

projects make it possible to introduce MBWT on

an initially small scale, and then to gradually

expand the throughput if the results are suc-

cessful.

One of the main criteria for the successful intro-

duction of MBWT is that the future operator

must be willing and able to indefinitely ensure

adherence to the operational requirements. Both

the operation of the MBWT facility and the

emplacement of residual, pretreated waste at

the landfill call for a large measure of expertise.

Despite the long duration of the pilot projects

and the training given to municipal workers,

sustainable operation of the MBWT facilities by

the communities themselves with no external

assistance could not have been assumed reali-

stically for either São Sebastião or Phitsanulok.

Communities that have nothing other than nor-

mal garbage dumps could not be expected to

meet the prerequisites for competent operation

of MBWT facilities without first having radically

altered their boundary conditions. In addition to

having qualified staff, successful implementation

of this new technology often requires internal

structural and organizational reform measures.

For any existing municipal administration, insti-

tuting such reforms must amount to a weariso-

me, time-consuming process. With a view to

accelerating the process, much can be said in

favor of establishing private-sector structures for

operation of an MBWT facility. However, even if

the facility is privatized, integration of the requi-

site expertise must be assured. As a rule, local

contractors lack such expertise, so partnerships

with competent external enterprises are recom -

mended. Such an approach has already been

implemented in São Sebastião, and similar

arrangements appear to be emerging in the

other pilot projects as well.

Sector Project MBWT - Final Report

64

5 Future Prospects of MBWT in Developing and

Threshold Countries

The close cooperation between GTZ, the partner

communities and private enterprises practiced in

the sector project has proved fruitful and contri-

buted decisively to the success of the pilot pro-

jects. Hence cooperation between communities

and private enterprises - public-private partners-

hips (PPP) - would appear to be sensible and

advisable for future implementation of MBWT in

developing and threshold countries. German

companies can assume an important role here.

Any disposal tasks to be contracted out to pri-

vate enterprises must be unequivocally descri-

bed in terms of the services to be rendered, and

all such services must be readily and unequivo-

cally verifiable for the communities. The results

of the sector project show that the attendant

quality control programs are not yet amenable to

local implementation. Consequently, programs

and methods of performance monitoring that are

commensurate with the communities' own

capabilities have to be developed.

All in all, the pilot projects generated lots of

public attention. Numerous native and foreign

visitors have toured the pilot projects in São

Sebastião and Phitsanulok, and the first pilot

projects dealt with in this report have since

given rise to numerous MBWT projects. In Bra-

zil, for example, other communities are also gea-

ring up to use MBWT as a component of their

municipal waste disposal systems. Hence the

São Sebastião pilot project has fully fulfilled its

function as a model project.

65

5.2 Comparison of Alternative Waste

Disposal Concepts

The pilot projects proved that MBWT can, under

certain sets of boundary conditions, serve as an

effective component of municipal solid waste

disposal in developing and threshold countries.

However, that does not answer the question as

to whether MBWT also constitutes the most

cost-effective solution. An objectively sound

decision can only be arrived at on a case-by-

case basis and in due consideration of all rele-

vant aspects. The various member countries of

the European Union give preference to different

avenues of disposal. According to the results of

the survey illustrated in Figure 42 below, some

70 % of all waste produced in the EU is dispo-

sed of in landfills, and approximately 20 % is

incinerated.

Sector Project MBWT - Final Report

66

100

90

80

70

60

50

40

30

20

10

0

Ave

nues

of

dis

po

ral [

wt.

%]

Avenues of waste disposal in the EU member countries

AU BE DK FI FR GE GR IR IT LU NL PO SP SW UK EU

Landfilling Incineration with energy recovery Incineration without energy recovery

Composting MBWT / landfill Fermentation

Figure 42: Avenues of waste disposal in EU member countries in 1999 [7]

Except in a few urban agglomerations, the inci-

neration of municipal solid waste in developing

and threshold countries is not a viable avenue of

disposal, if only for economic reasons. However,

the objective of reducing the emission potentials

of MSW could also be achieved by means of

separate collection and recycling of the organic

components. Another conceivable solution is to

combine composting with MBWT.

In any case, the benefits of the various alternati-

ves can only be secured if certain assumptions

are fulfilled. For example, the anticipated results

of MBWT decomposition processes can only be

achieved if the facility is actually being operated

with due competence. Likewise, the hoped-for

income from composting can only be realized if

the compost is of good quality and can be suc-

cessfully marketed.

The comparison of alternatives as a basis for

deciding on a waste disposal concept will

always include some unavoidable uncertainties.

The degree of uncertainty will depend on how

much experience has been gained through

application of the various alternatives. In order

to minimize the risks resulting from uncertain

assumptions, new processes should always first

be field-tested and then implemented in stages.

Extensive MBWT processes, for example, can

be tested by way of scale-model trials followed

by large-scale pilot schemes to establish the

process suitability while adapting it to fit the

local boundary conditions. The treatment pro-

cesses dealt with in this report allow such a

step-by-step form of introductory implementa-

tion.

Also, MBWT enables the separation of high-

energy fractions at the mechanical conditioning

stage. That, in turn, makes it possible to integra-

te additional paths of recovery and disposal into

the waste management system, extending

beyond mere improvements in the waste dispo-

sal situation.

5.3 Need for Further Study

This sector project provided a crucial point of

departure for assessing the perspectives of

MBWT in developing and threshold countries,

but the duration of the project did not suffice to

find conclusive answers to all questions, and

there was little empirical background to draw on

regarding the construction and operation of

lined and sealed landfills in tropical and subtro-

pical areas. Indeed, the since acquired know-

how shows that waste-disposal standards deve-

loped in Central Europe cannot be applied to

such areas without further ado. Hence there is a

continuing need for further investigation into

various aspects of MBWT, including and in parti-

cular the following:

Landfilling concept as a function of climate and

waste composition

Observations made at landfills in tropical and

subtropical areas show that organic decomposi-

tion proceeds much more rapidly there than it

does in more temperate climates. A systematic

analysis of relevant empirical data could have a

fundamental impact on the operation of such

landfills. For example, the prevailing routine

practice of immediately compacting the empla-

ced waste and covering it with a layer of topsoil

at the end of each day requires systematic

management of the incidental leachate and

landfill gas. That, however, is still unrealizable in

many countries. Consequently, different ways of

modifying landfill concepts to achieve extensive

aerobic decomposition of the organic fraction

directly at the landfill need to be investigated

(including "shredded refuse landfills" as the

most elementary form of MBWT).

67

Development of appropriate leachate-treatment

strategies

It makes no sense to line a landfill unless the

leachate can be reliably disposed of. However,

German leachate-treatment standards cannot be

realized in most developing and threshold coun-

tries. What are therefore needed are leachate-

treatment concepts that are feasible in both the

technical and the financial sense. On the other

hand, the importance of MBWT increases in tan-

dem with the risks and costs of leachate treat-

ment.

Climate relevance of waste pretreatment

The anaerobic decomposition of organic waste

in landfills generates large amounts of climate-

destabilizing methane. Even quite elaborate gas-

management systems are only able to trap part

of the generated methane, and in many coun-

tries any efficient form of gas collection and

recycling would simply be too expensive. Thus

waste pretreatment constitutes a comparatively

simple and efficient way of reducing methane

emissions. The effects of various waste disposal

concepts that could be implemented in develo-

ping countries need to be investigated in terms

of their climatic impacts. Then the findings

should be used to develop standards for ensu-

ring that decisions on waste-disposal concepts

are made in due consideration of climatic fac-

tors.

Material-flow steering and waste recycling

The mechanical conditioning stage of MBWT

allows the separation of waste fractions for pur-

poses of recycling and energy recovery. In many

developing and threshold countries the informal

sector has traditionally been largely responsible

for the recovery of resources. Consequently,

concepts geared to increasing the recycling

quotas should allow for the needs and capabili-

ties of the informal sector. Projects in Ilhabela,

Brazil, and in Atlacomulco, Mexico, have yielded

experience in informal-sector involvement, and

the lessons learned there need to be broadened

and disseminated.

Landfilling of pretreated waste

With regard to in-dump behavior, MBWT waste

differs greatly from untreated waste. Its main

advantages include better compressibility and

less emission potential. However, the studies

conducted within the scope of the pilot projects

have shown that the disposal of pretreated

waste in landfills in areas with high rates of pre-

cipitation is inherently problematic. Ways and

means of optimizing the emplacement of pretre-

ated waste in areas with high rates of precipita-

tion need to be developed.

Long-term in-dump behavior

One of the main advantages of MBWT is that it

promises to radically improve the landfill situa-

tion. Precisely for that reason, however, there is

need for further investigation of the long-term

behavior and leachate emissions of pretreated

waste.

Monitoring

Germany has extensive codes and standards

and the appropriate technical equipment for

securing and monitoring waste treatment and

disposal targets. Many developing and threshold

countries, however, still lack all or some of the

corresponding codes, standards and equipment.

It is therefore necessary to develop and imple-

ment appropriate standards and monitoring

methods.

Sector Project MBWT - Final Report

68

This report presents the main activities and

results of the sector project "Promotion of

Mechanical-biological Waste Treatment", which

was carried out by Deutsche Gesellschaft für

Technische Zusammenarbeit (GTZ) GmbH from

1998 to 2003 on behalf of the Federal German

Ministry for Economic Cooperation and Deve-

lopment (BMZ). The purpose of the project was

to investigate potential applications for mechani-

cal-biological waste treatment in developing

countries by way of know-how interchange, pilot

projects, etc. and to describe the prospects and

risks of application.

In addition to drawing up reference material and

decision-making aids for MBWT applications,

the sector project also focused on practical field

testing of mechanical-biological waste treatment

in various countries under various sets of boun-

dary conditions (e.g. climate and waste compo-

sition). Several specialized German enterprises

served as partners in cooperation for preparing

and implementing the "pilot projects". This co-

operation with the private sector made it possi-

ble for the pilot projects to employ processing

techniques and throughput rates that closely

resembled those encountered in normal opera-

tion, hence yielding reliable results. The pilot

projects also included as important components

training programs designed to gradually put the

partners from developing and threshold coun-

tries in a position to handle the field-tested tech-

nologies on their own.

The results are essentially outlined in this report

on the basis of the commercial-scale pilot pro-

jects in São Sebastião, Brazil, and Phitsanulok,

Thailand, and the scale-model trial in Al-Sala-

mieh, Syria. Both in São Sebastião and in Phit-

sanulok, a non-mobile biotreatment-windrow

approach (FABER-AMBRA® process) was adop-

ted, while force-ventilated heaps with an inert,

semi-permeable laminated-tarpaulin cover (W.L.

Gore) were used in Al-Salamieh.

The experience gained in the pilot projects

shows that mechanical-biological waste treat-

ment can be successfully implemented in deve-

loping and threshold countries. The biological

decomposition processes employed in the sub-

ject pilot projects achieved satisfactory results.

The São Sebastião MBWT facility has since

commenced normal operation and yielded a

radically improved landfill situation.

The specific pretreatment costs determined in

the course of the pilot projects range between

11 and 15 Euro/Mg, but MBWT does not only

generate costs, it also generates savings in

waste disposal. The economizing effect at the

landfill end stems mainly from a reduction in

mass and the enhanced compressibility of the

pretreated waste. MBWT also reduces leachate

incidence and pollution, as well as the formation

of landfill gas. MBWT can reduce the cost of

landfill aftercare and increase several times over

the useful life of landfills.

69

6 Summary

On the other hand, the project also revealed that

in order to achieve the targeted results, even

"simple techniques" that have already been

well-proven in Germany require appropriate

adjustment to the respective local situation in

other countries (especially with regard to climate

and waste composition). One of the main criteria

for the successful introduction of MBWT is that

the future operator be willing and able to inde-

finitely ensure adherence to the operational

requirements. Both the operation of the MBWT

facility and the employment of residual, pretrea-

ted waste at the landfill call for a large measure

of expertise. Despite the long duration of the

pilot projects and the training given to municipal

workers, sustainable operation of the MBWT

facility by the communities themselves, i.e. with

no external assistance, could not have been as-

sumed realistically. In São Sebastião, the crea-

tion of private-sector structures, including the

participation of a German enterprise, made it

possible to ensure the long-term operation of

the MBWT facility.

Sector Project MBWT - Final Report

70

The results of this sector project provide a good

basis for evaluating the perspectives of MBWT

in developing and threshold countries. Under

favorable boundary conditions MBWT can also

constitute an effective element for the disposal

of municipal solid waste. Whether or not MBWT

would actually be the most favorable solution in

any given case can only be decided in due con-

sideration of all relevant aspects. Since the

duration of the project did not suffice to find

conclusive answers to all questions, this report

calls attention to some remaining uncertainties

and to the need for further studies and

investigations.

71

APPENDICES

Sector Project MBWT - Final Report

72

Appendix 1 Characterization of the Pilot Projects

Project characterization - São Sebastião, BrazilProject designationPilot Project, São Sebastião, Brazil

Country, communityBrazil, São Sebastião

Beginning, endMay 2000 - end of 2002

CharacterPublic-private partnership

MiscellaneousThe local government has adopted the process on the basis of alicense model. MBWT and landfill privatized in March 2002

Partners in cooperationGTZ sector project "Promotion of Mechanical-biological Waste Treatment" Official contact Elke Hüttner, Division OE44; Phone: ++49 6196 79 0e-mail: elke.huettner@gtz.de;Internet: www.gtz.de/mba/

Wilhelm Faber GmbH Wolfgang Tönges; Phone: ++49 6731 492 - 117e-mail: w.toenges@faber-gruppe.com; Internet: www.faber-ambra.de

Prefeitura Municipal de São SebastiãoSecretaria de Meio Ambiente e Urbanismo; Secretário Sr. José Teixeira FilhoRua Amazonas 13Centro - São Sebastião - SP - 11600/000Tel. +55-12-38926000; Fax. +55-12-38922819 Internet: www.saosebastiao.sp.gov.br

DescriptionShort description of the project Pilot project for appraising the suitability of, and appropriately adapting, the FABER-AMBRA® process of Wilhelm Faber GmbH(non-mobile, passive ventilation, with mechanical pretreatment) for application in Brazil; transfer of process know-how via trainingand local backstoppingLocal integrationIntegration into the landfill environment, treatment of all waste inputs since March 2002, disposal to mono-landfill since June 2002

Technical descriptionBasic waste-management dataPopulation served: approx. 65,000 year round, and up to300,000 during the summer tourist seasonRainy season: Nov.-Mar., approx. 2,400 mm annual precipitation Annual waste input: 30,000 Mg (in 2001)Waste composition: 50 - 60 wt.% organicsWater content: > 60 wt.%Plant capacity: up to 250 Mg/d, 30,000 Mg/a

Employed technologyDelivery by collecting vehicle or container truckRegistration of weight and origin via truck weigherConditioning/preparation Manual presorting by employeesHomogenizing drum, i.e. modified rotary drum vehicle from Ger-many, capacity: 7 MgTotal of 3 vehiclesHomogenization and comminution of waste inputEach batch takes 70 minutes, incl. 45 min for homogenizationDecompositionPreparation of heap base with pallets and drain pipesBuilding of heaps with excavator (30-39 m wide, 2.5 m high)Covering with biofilter, installation of watering system and sam-pling gaugesDecomposing time: 9 months; temperature-controlled processTeardown of heaps with excavatorDisposal of outputMechanical conditioning (e.g. screening) planned, but no experi-ence gathered, emplacement in sealed-base landfill via compac-tor

Photos

Local peculiaritiesPopular tourist area with pronounced differences in waste inci-dence between tourist season and off-season; community stret-ched out over more than 100 km; high transportation costs

Present state and activities to dateWaste treatment commenced in 05/00;All waste input treated since 03/02; privately operated, leachatequality and heap-teardown techniques tested on trial heap

Planned activitiesCompletion of leachate pond; investigation of leachate disposalat nearby sewage treatment plant

Project status

Technoscientific investigations and findingsExtensive test program to determine in-heap gas composition, temperature profiles, sampling of inputs and other material, analysisof leachate from treated, landfilled waste and from heaps

Particularities, remarks

The completed test heap

Landfill following conversion to MBWT (Bird's eye view)

Basic waste-management dataPopulation served: approx. 130,000Rainy season: May - Oct., annual precipitation approx. 1,350 mmAnnual waste input: 33,500 Mg (in 2001)Waste composition: 50- 60 wt.% organics

25 wt. % plasticsWater content: > 60 wt.%Plant capacity (of pilot project): 40 Mg/d, 14,600 Mg/a

73

Project characterization - Phitsanulok, ThailandProject designationPilot project Phitsanulok Thailand

Country, communityThailand, Phitsanulok

Beginning, endNovember 2001 - middle to end of 2003

CharacterPublic-private partnership

MiscellaneousLocal government intends to adopt the process on the basis ofprivatized waste treatment in the future

Partners in cooperationGTZ sector project "Promotion of Mechanical-biological Waste Treatment" Official contact Elke Hüttner; Division OE44; Phone: ++49 6196 79 0e-mail: elke.huettner@gtz.de; Internet: www.gtz.de/mba/

Wilhelm Faber GmbH Wolfgang Tönges, Phone: ++49 6731 492 - 117e-mail: w.toenges@faber-gruppe.com; Internet: www.faber-ambra.de

Municipality of Phitsanulok, Thailand in cooperation with:Thai-German Solid Waste Management Programme for PhitsanulokPhitsanulok Municipal OfficeBaromtrilokanat Road, Muang District,Phitsanulok 65000, ThailandPhone ++66-55-232300, 232301 Fax ++66-55-232300e-mail: swmphit@psnulok.loxinfo.co.th; Internet: www.gtzth.org

DescriptionShort description of the project Pilot project for appraising the suitability of, and appropriately adapting, the FABER-AMBRA® process of Wilhelm Faber GmbH(non-mobile, passive ventilation, with mechanical pretreatment) for application in Thailand; transfer of process know-how via trai-ning and local backstopping

Employed technologyDelivery by collecting vehicle or container truckRegistration of weight and origin via truck weigher Conditioning/preparationManual presorting by waste pickers and possibly employeesHomogenizing drum, i.e. modified rotary drum vehicle from Ger -many, capacity: 7 MgHomogenization and comminution of waste inputEach batch takes 70 minutes, incl. 45 min for homogenizationDecompositionPreparation of heap base with pallets and drain pipesBuilding of heaps with excavatorCovering with biofilter, installation of watering system and sam-pling gaugesDecomposing time: 9 months; temperature-controlled processTeardown of heaps with excavatorDisposal of outputThin-layer emplacement by compactor (initial trials)

Local peculiaritiesWell-developed private recycling sector, large water and plasticsfractions, little structural material in residual waste

Present state and activities to dateWaste pretreatment commenced in 01/02 Three trial heaps on the old landfill, paved/reinforced waste-treatment area since 08/02; two test heaps

Planned activitiesDetermination of packed density, mass and volume analyses (inprocess) with decomposition lossesHydrological balance

Technoscientific investigations and findingsExtensive test program to determine in-heap gas composition, temperature profiles, sampling of inputs and other material, analysisof leachate from treated, landfilled waste and from heaps; analysis of decomposed material

Particularities, remarksSometime in 2003 the local government is expected to reach a decision on adoption of the process and to privatize operation ofthe landfill or pretreatment of the waste (MBWT) by way of competitive tendering.

Landfill entry point

Decomposing heap with coconut-shell biofilterProject status

Local integrationIntegration into the landfill environment Cooperation with the local GTZ project: "Solid Waste Management Programme for Phitsanulok"

Technical description Photos

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Project characterization - Al-Salamieh, SyrienProject designationAppropriate waste disposal for threshold and developing coun-tries

Country, communitySyria. Al-Salamieh

Beginning, endJan. 99 - end of 2002, early 2003

CharacterResearch project

MiscellaneousEstablishment of the process in Al-Salamieh within the scope ofthe PPP measure to follow this research project.

Partners in cooperationGTZ sector project "Promotion of Mechanical-biological Waste Treatment" Official contact Elke Hüttner; Division OE44; Phone: +49 6196 79 0e-mail: elke.huettner@gtz.de; Internet: www.gtz.de/mba/

University of Kassel, Civil Engineering Department, Waste TechnologyFaculty / Dr.-Ing. Aber MohamadPhone: +49 561 804 3954, e-mail: aber.mohamad@uni-kassel.de

Solid Waste Treatment W.L. Gore & Associates GmbHLothar Deyerling Phone: +49 89 12 27 26e-mail: ldeyerling@wlgore.com

The Syrian Arab RepublicMinistry of Local AdministrationGovernorate of Hama, Salamieh Municipal Council

Description

Short description of the project Research project for investigating the suitability of, and for appropriately adapting, the Gore laminate process (force-ventilated,controlled-heap decomposition with inert semi-permeable laminate cover) as a technically uncomplicated, relatively inexpensive,easy to operate, quickly implementable waste treatment facility for the production and quality control of soil conditioners (com-post).

Local integrationIntegration into the waste sector and landfill environment, composting of biowaste, cooperation with local specialists and training of sector employees

Technical descriptionBasic waste-management dataPopulation served: approx. 125,000Rainy season: Oct. - April, precipitation approx. 300 mmAnnual waste input: 20,000 Mg (in 2001)Waste composition: 70 wt.% organics

10 wt.% plasticsWater content: > 60 wt.%Planned plant capacity: 40-50 Mg/d, 15,000 Mg/a (treatment of approx. 220 Mg in scale-model trial)

Employed technology Delivery: by collecting vehicleRegistration of weight and origin via truck weigher Conditioning/preparation: Manual presorting by waste pickersand possibly employeesHomogenization and comminution of the waste in a mobile com-minutor; planned: 10 Mg/h homogenizing drum made in SyriaDecomposition: Construction of channels for ventilation anddrainage / collection of leachate; manual setting up and tearingdown of heaps; inert, semi-permeable laminate cover; three-month composting process, controlled via temperature and oxy-gen level; use of excavator and wheel loader plannedDisposal of output: Mechanical conditioning (screening) andseparation of fine material as compost in the handling of bio-waste; otherwise disposal to landfill.

Local peculiaritiesWell-developed private recycling sector (waste pickers), largewater and plastics fractions; plastic bags, little structural materi-al in household waste; dryness; high organic fraction

Photos

Present state and activities to dateThe research project "Appropriate waste disposal for TC andDC" has been completed. Preparations for a PPP program forimplementation of residual-waste treatment incl. separation ofuseful compost fraction, is under way. Plant scheduled for com-missioning May 2003.

Planned activitiesConstruction and commissioning of waste-treatment facility, trai-ning program, public awareness-raising, use of compost outputin agriculture, scientific backstopping program

Technoscientific investigations and findingsExtensive test program to determine waste composition, temperature profiles, water content, ignition loss, nutrients and heavymetals, sampling of inputs and other material

Particularities, remarksThanks to forced ventilation and covering of the heaps, no watering was necessary for the duration of mechanical-biological treat-ment, because the evaporated water condensed on the inside of the laminate cover and dripped back onto the decaying material.

Cover and forced ventilation of heaps

Heap with ventilating elements (aerators)Project status

75

Project characterization - Atlacomulco, MexicoProject designationPilot project, Atlacomulco Mexico

Country, communityMexico, Atlacomulco

Beginning, endSeptember 2002 - August 2003

CharacterPublic-private Partnership

MiscellaneousAdoption of the process for the landfill by the local administra-tion envisaged within the framework of a commercial contract

Partners in cooperationGTZ sector project "Promotion of Mechanical-biological Waste Treatment" Official contact Elke Hüttner; Division OE44; Phone: ++49 6196 79 0e-mail: elke.huettner@gtz.de; Internet: www.gtz.de/mba/

Faber Recycling GmbH Wolfgang Tönges Tel.: +49 6731 492 - 117e-mail: w.toenges@faber-gruppe.com; Internet: www.faber-ambra.de

Honorable Ayuntamiento de AtlacomulcoState of Mexico, Mexico

Secretaría de Ecología del Estado de México(State Ministry of the Environment) State of Mexico, Mexico

DescriptionShort description of the project Pilot project for introducing integrated waste management (recycling, composting, residual-waste treatment, landfill-ing) in applica-tion of the FABER-AMBRA® process of Wilhelm Faber GmbH (non-mobile, passively ventilated heaps, with mechanical conditio -ning) for waste treatment and compost production, transfer of know-how by training and local project backstopping, integration ofthe informal sector ("Pepenadores")

Local integrationIntegration of "Pepenadores" upon introduction of integrated waste managementCooperation with the local GTZ project "Decentralization of Waste Management in the State of Mexico"

Technical descriptionBasic waste-management dataPopulation served: approx. 50,000Rainy season: May - Oct., precipitation approx. 1,000 mmAnnual waste input: 20,000 Mg (estimated)Waste composition: 50- 60 wt.% organicsWater content: > 60 wt.%Planned plant capacity: 40 Mg/d, 12,000 Mg/a

Photos

Employed technologyDelivery by collecting vehicle and container truck;No registration of weight or origin of wasteConditioning/preparation Manual sorting by "Pepenadores" and possibly employeesHomogenizing drum as an individually modified rotary drummachine from Germany; capacity: 7 MgHomogenization and comminution of waste materialEach batch takes 70 minutes, incl. 45 min for homogenization DecompositionPreparation of biological treatment with pallets and drain pipesBuilding of heaps with excavatorCover with geofilter, manual irrigation, monitoring of gas, tem-perature and process waterPlanned decomposing time: 9 months, process control via tem-perature measurementsTeardown of heaps with excavatorDisposal of outputFirst, mechanical conditioning (e.g. screening): planned, but noexperience gained to date

Local peculiaritiesNo organic biofilter material available; use of slightly geogenousmaterial as cover for the heaps

Present state and activities to dateWaste treatment commenced in 11/ 02, three test heaps on an old leachate pond; new heaps put up innew grounds since 01/03.

Planned activitiesIntroduction of separate waste collection in certain parts of townto obtain mono-batches of biowaste for compost production

Technoscientific investigations and findingsExtensive test program to determine in-heap gas composition, temperature profiles, sampling of inputs and other material as of03/03 by CENICA (Mexico)

Particularities, remarks

First group of trainees

Building of the first heapProject status

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76

Project characterization - ColombiaProject designationPromotion of ecologically sound waste management in Colombia

Country, communityColombia, Greater Armenia Area, Quindío

Beginning, end1 Aug. 2001 - 31 Dec. 2002

CharacterPublic-private partnership, technical school, social project, Recicladores, Internet portal

Partners in cooperation

GTZ Centre for Cooperation with the Private SectorOfficial contact: Helma Zeh-Gasser; Phone ++49 6196 79 0e-mail: ppp-buero@gtz.de

Ingenieurbüro für innovative Abfallwirtschaft (ia) GmbH, Werner Bauer ++49 89 18935-0e-mail: info@ia-gmbh.de

B.A.U.M. TRACOM Ltda, BogotáArmenia, Quindío, ColombiaURL: www.baumgroup.com; E-Mail: l.navas@baumgroup.com

DescriptionShort description of the project Pilot project for implementing an integrated approach to sustainable development via theoretical and practical training in "integra-ted waste management" and "sustainable waste management". Establishment of a technical school. Planning/construction/opera-tion of a model MBWT facility, incl. practical training. Training of specialists to serve as trainers. Integration of the Recicladorescooperatives. Summarization and publication of experience gained via the Internet portal "ForumZ for Latin America" (www.foro-z.com).

Local integrationElaboration and provision of training; planning and implementation of a social project; goals include strengthening and stabilizationof democratic structures and of municipal self-administration.Permanent local project partners: Cámara de Comercio de Armenia, Servicio Nacional de Aprendizaje SENA Quindío, UniversidadEmpresarial Armenia

Technical descriptionTMB demonstration facility

Employed technologyDelivery by container truck, with registration of waste origin (hauling andcollecting routes) and weight (truck weigher)Receiving point Waste receiving, input check, registrationMechanical conditioning Coarse and fine sorting, screening(manual)Separation of interfering objects,pollutants and recyclables (manual)Comminution, homogenization (mixing drum)Weighing of all material fractionsBiological (aerobic) treatmentIndoor composting in bamboo composting bins;No active ventilationCollection of leachate and process waterMechanical post-treatmentScreening and, as necessary, post-composting

Basic waste-management dataNo separate collection of wasteNo waste treatment and landfilling to technical standardsHigh organic fraction ( ~ 70 wt.%)Temporary TMB demonstration facility with separation and com-post-ing of a) household waste, b) central market waste, and c)waste from gardens and parks

Photos

Local peculiaritiesDisposal of residual waste: ~15-20 % of material inputIntegration of Recicladores cooperatives, incl. trainingLack of overall waste-management strategyMunicipal dump (Armenia) soon to close (Dec. 2002), but noconcrete alternative plans to date.

Project statusPresent state and activities to dateThe project is completed.Design/implementation of Internet portals complete: www.foro-z.com (knowledge portal) and www.coltec.info (training portal) Planning/construction/commissioning of MBWT facility

Planned activitiesPlanned continuation of operation of the MBWT facility up toearly 2003 by students from SENA Armenia; attendant scientificinvestigations and training; planned continuation of coop. anddevelopment of new projects upon completion of GTZ project.

Technoscientific investigations and findingsEcological evaluation of the process (stocktaking); comprehensive analysis of temperature, leachate and compost;material-flow documentation for the generation of mass balances

Particularities, remarksDue to acute political tensions in Colombia the project has suffered substantial delays since the beginning of the year. Knowledgenetworking interconnection with the GTZ project REPAMAR (Latin American Network for Waste Management, based in Lima). Asthe project progressed, cooperation with Servicio Nacional de Aprendizaje SENA in Quindío, and with its professors and students,has deepened.

Indoor part of model facility

Bamboo composting bins

77

1. Gernod Dilewski

Infrastruktur & Umwelt, Professor Böhm und Partner

Julius-Reiber-Straße 17

D- 64293 Darmstadt

Phone: +49 (0)6151 / 81 30 0

Fax: +49 (0)6151 / 81 30 20

URL: www.iu-info.de

E-Mail: gernod.dilewski@iu-info.de

2. Abir Ismail

P.O. Box 34 880

Damascus

Syria

E-Mail: abirgh@scs-net.org

3. Gabriele Janikowski

IKW Beratungsinstitut für Kommunalwirtschaft GmbH

Bayenthalgürtel 4

D- 50968 Cologne

Phone: +49 (0)221 / 93 70 91 0

Fax: +49 (0)221 / 93 70 91 11

URL: www.ikw.de; E-Mail: g.janikowski@gmx.de

4. Dr. Dirk Maak

Wilhelm Faber GmbH

Galgenwiesenweg 23-29

D - 55 232 Alzey

Phone: +49 (0)6731 / 492 114

Fax: +49 (0)6731 / 492 115

URL: www.faber-ambra.de

E-Mail: maak@faber-gruppe.com

5. Dr. Aber Mohamad

University of Kassel - Waste Technology Faculty

Mönchebergstraße 7

D- 34125 Kassel

Phone: +49 (0)561 / 95 29 095

Fax: +49 (0) 561 / 95 29 098

URL: www.uni-kassel.de/fb14/abfalltechnik/

E- Mail: aber.mohamad@uni-kassel.de

Postfach 34 880

Damascus Syria

E-Mail: abirgh@scs-net.org

6. Dr. Dieter Mutz

Basel University of Applied Sciences (FHBB)

Institute for Environmental Technology (IfU)

Fichtenhagstr. 4

CH- 4132 Muttenz

Switzerland

Phone: +41 (0)61 / 4674 568

Email: d.mutz@fhbb.ch

7. Dr. Anna Lúcia Florisbela dos Santos

Segunda Privada de Támesis 36

Condado de Sayavedra

52938 Atizapan de Z.

Edomex / México

E-Mail: alflorisbela@aol.com

8. Bernhard Schenk

Independent Engineer & Consultant

Planckstrasse 20 a

D-10117 Berlin

Phone: +49 (0)177 / 36 00 299

Fax +49 (0)30 / 208 16 37

bernhard_schenk@yahoo.de

9. Gregório Alziro da Silva

Rua Noronha Torrezão, n.742, ap. .602

Cubango, Niterói - RJ.

Brazil

Phone: +55 (0)21 / 710 2362

10. Joachim Stretz

Technischer Umweltschutz - Environmental Engineering

Graefestr. 4

D- 10967 Berlin

Phone +49 (0)30 / 814 923 95

Fax. +49 (0)30 / 814 923 96

URL: www.j-stretz.de; E-Mail: mailto@j-stretz.de

Appendix 2 List of Important Contacts

Team of experts

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78

List of Important Contacts

1. Federal German Ministry for Economic

Cooperation and Development - BMZ

Dr. Annette van Edig

Friedrich-Ebert-Allee 40

D- 53113 Bonn

Phone: +49 (0)228 / 535 3761

Fax.: +49(0)1888 / 535 3500

URL: www.BMZ.de

E-Mail: vanedig@bmz.bund.de

2. Federal German Ministry for Education and

Research - BMBF

Dr. Jürgen Heidborn

Bonn Office

Heinemannstr. 2

53175 Bonn - Bad Godesberg

Berlin Office

Hannoversche Straße 30

D- 10115 Berlin

Phone: +49 (0)1888 / 57- 3541

Fax: +49 (0)1888 / 57- 83601

URL: www.BMBF.de

E-Mail: heidborn@bmbf.bund400.de

3. Projeto Gestao Ambiental Urbana - GAU

Dr. Detlev Ullrich

Largo IBAM n° 1, Humaita

22271-070 Rio de Janeiro

Brazil

Phone: +55 (0)21 2535 3434

Fax: +55 (0)21 2526 2464

URL: www.gau.org.br

E-Mail: detlev.ullrich@gau.org.br

4. Prefeitura Municipal de São Sebastião

Secretaria de Meio Ambiente e Urbanismo

Secretário Sr. José Teixeira Filho

Rua Amazonas 13

Centro - São Sebastião - SP - 11600/000

Phone +55 (0)12/ 38926000

Fax. +55 (0)12 / 38922819

URL: www.saosebastiao.sp.gov.br

5.Prefeitura Municipal de Ilhabela

Secretaria Municipal de Meio Ambiente

Rua Pref. Mariano Procopio de

Araujo Carvalho no. 86

Barrio Pereque-Ilhabela

SP-Brasil-CEP 11630-000

Brazil

Phone: +55 (0)12 / 472 2200

ramal 147

URL: www.ilhabela.sp.gov.br

E-Mail: ilhabela.ambiente@iconet.com.br

6. Municipality of Phitsanulok

Solid Waste Management Programme

for Phitsanulok

Dr. Walter Schöll

Phitsanulok Municipal Office, Muang District

Phitsanulok 65000

Thailand

Phone: +66 (0)55 / 23 23 00

Fax: +66 (0)55 / 23 23 00

E-Mail: swmphit@psnulok.loxinfo.co.th

7. Apoyo a la Gestión de Residuos Sólidos

Municipales en el Estado de México

Dr. Günther Wehenpohl

Parque de Orizaba No. 7; 7. Piso

Col. Del Parque

53390 Naucalpan

Estado de México

Phone / Fax: ++52 (0)55 / 5576-4417

E-Mail: GTZ-SEGEM@gtz.org.mx

8. B.A.U.M. TRACOM Ltda

Ignacio Navas

Carr 13 No. 96 - 82 of. 103

Bogotá D.C.

Colombia

Phone: +57 (0)315 / 301 92 94

Fax: +57 (0)1 / 636 30 87

URL: www.baumgroup.com

E-Mail: l.navas@baumgroup.com

79

9. Knoten Weimar - International Transfer Center

for Environmental Biotechnology

Braunschweig Technical University

Leichtweiss Institute, Waste-management

Department

Prof. Dr.- Ing. Klaus Fricke

Dipl.-Ing. Heike Santen

Beethovenstraße 51 a

D- 38106 Braunschweig

Phone: +49 (0)531 / 391 3969

Fax.: +49 (0)531 / 391 4584

URL: www.bionet.net

E-Mail: klaus.fricke@tu-bs.de

10. Wilhelm Faber GmbH

Wolfgang Tönges

Dr. Dirk Maak

Galgenwiesenweg 23-29

D- 55 232 Alzey

Phone: +49 (0)6731 / 492 232

Fax: +49 (0)6731 / 492 283

URL: www.faber-ambra.de

E-Mail: w.toenges@faber-gruppe.com

11. University of Kassel

Waste Technology Faculty

Prof. Dr.-Ing. Arnd Urban

Dr.-Ing. Aber Mohamad

Mönchebergstraße 7

D- 34125 Kassel

Phone: +49 (0)561 / 95 29 095

Fax: +49 (0) 561 / 95 29 098

URL: www.uni-kassel.de/fb14/abfalltechnik/

E- Mail: urban@uni-kassel.de

12. Solid Waste Treatment W.L.

Gore & Associates GmbH

Lothar Deyerling

Hermann-Oberth-Str. 24

D-85640 Putzbrunn

Phone: +49 (0)89 / 4612 2726

Fax: +49 (0)89 / 4612 4 2726

E-Mail: ideyerling@wlgore.com

13. Ingenieurbüro für innovative Abfallwirtschaft

GmbH; iA GmbH

Werner P. Bauer

Gotzinger Str. 48/50

D- 81371 Munich

Phone: +49 (0)89 / 189 35 0

Fax: +49 (0)89 / 189 35 199

URL: www.ia-gmbh.de

E-Mail: info@ia-gmbh.de

14. Sustainable Technologies, Building-Business

Consultants (TBW) GmbH

Hr. Hartlieb Euler

Baumweg 10

D- 60316 Frankfurt am Main

Phone: +49 (0)69 / 9435 070

Fax: +49 (0)69 / 9435 0711

URL: www.tbw-frankfurt.com

E-Mail: info@tbw-frankfurt.com

15. Ingenieurgemeinschaft Witzenhausen

IGW Fricke & Turk GmbH

Bischhäuser Aue 12

D- 37 213 Witzenhausen

Phone: +49 (0)5542 / 93 080

Fax: +49 (0)5542 / 93 08 20

E-Mail: c.werner@igw-witzenhausen.de

16. INTECUS Dresden GmbH

Pohlandstraße 17

D- 01309 Dresden

Phone: +49 (0)351 / 318 23 14

Fax: +49 (0)351 / 318 23 33

URL: www.intecus.de

E-Mail: intecus.dresden@t-online.de

17. Faber Serviço Ltda.

Christiane Dias Pereira

Rua Duque de Caxias, 188

2° Piso - SALA 13

Centro - São Sebastião

São Paulo, 11600-000

BRASIL

Phone/Fax: +55 (0)12 38 93 10 12

E-Mail: faberbrasil@uol.com.br

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18. Wilhelm Faber GmbH

Maria Elena Mendoza

Galgenwiesenweg 23 - 29

D- 55232 Alzey

Phone/Fax: +52 (0)712 1228 127

E-Mail: faber-me@gmx.net

19. Wilhelm Faber GmbH

Chaiwat Teankum Schlicht

Galgenwiesenweg 23 - 29

D- 55232 Alzey

Phone: +66 (0)1 820 52 76

Fax: +66 (0)55 21 79 35

E-Mail: faber-thailand@gmx.net

20. Dr. Kornelia-Theodora Drees

Viktoriaallee 46

D- 52066 Aachen

Phone: +49 (0)241 / 997 997 87

21. Dagmar Diebels

Filmteam

Goffartstraße 44

D- 52066 Aachen

Phone: +49 (0)241 / 51 51 064

22. Technical University Hamburg

-Harburg - TUHH

Waste Management Section

Prof. Dr. Rainer Stegmann

Fr. Ina Körner

Harburger Schlossstrasse 36

D- 21079 Hamburg

Phone: +49 (0)40 / 42878 3154

23. IKW Beratungsinstitut für Kommunalwirt-

schaft GmbH

Gabriele Janikowski

Bayenthalgürtel 4

D- 50968 Cologne

Phone: +49 (0)221 / 93 70 91 0

Fax: +49 (0)221 / 93 70 91 11

URL: www.ikw.de

E-Mail: g.janikowski@gmx.de

24. Infrastruktur & Umwelt, Professor Böhm und

Partner

Gernod Dilewski

Julius-Reiber-Straße 17

D- 64293 Darmstadt

Phone: +49 (0)6151 / 81 30 0

Fax: +49 (0)6151 / 81 30 20

URL: www.iu-info.de

E-Mail: gernod.dilewski@iu-info.de

25. Dr. Uwe Cusnick

Organization Consultant

Wehrhofstraße 1

D- 60489 Frankfurt

Phone: +49 (0)69 / 789 39 15

Mobil: +49 (0)179 / 699 29 15

E-Mail: uwecusnick@aol.com

81

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83

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Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH- German Technical Cooperation -Dag-Hammarskjöld-Weg 1-5Postfach 518065726 Eschborn, GermanyTelephone: +49 (6196) 79-0Fax: +49 (6196) 79-1115Internet: http://www.gtz.de

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