Solid wastes

Issues and Approach

Presented by

Santhosh kumar

GARBAGE CRISIS

REASONS

The rapid urbanization.

Neglect from authorities.

Public apathy towards solid waste

sector.

WHY ACTION IS REQUIRED ON WAR FOOTING ?

Municipal Solid Waste (Management and Handling) Rules 2000.

Municipal authorities in the country to implement proper Solid Waste Management System by December 2003

Spread of epidemics in various parts of the Country.

Opposition from the communities encircle the existing dump sites.

Litigations against various ULB s. Public awareness

OBJECTIVE OF THE REPORT

To discuss,

Present situation

Various methods available for treatment of solid wastes

Operational aspects of solid waste treatment systems

Requirements for an effective solid waste management (SWM) system.

Importance of Awareness and community level initiatives.

SOLID WASTE GENERATION IN

KERALA

Kerala generates approximately 3,000

tones of solid waste daily.

Only less than a half of this is removed

from the streets

Only a tiny portion is processed or

recycled.

Rest is simply dumped in water bodies or

at land-filling sites.

EFFECTS OF INDISCRIMINATE

DUMPING OF WASTE

Blockage of drainage channels contributing to flooding.

Spreading of diseases by different vectors like insects, rodents and birds.

Emissions of green house gas that contributes global warming effect. (Methane is 20 times more harmful than CO2 in this regard)

Contamination of surface and ground water through leachate.

Soil contamination through direct waste contact or leachate.

Air pollution by burning of wastes

EFFECTED PARTIES

All people in general

Urban poor and slum dwellers are the

most effected.

Wealthy residents avoid direct exposure of

garbage piles close to home and the

problems are shifted away from their

neighborhood to elsewhere.

The Ministry of Environment and Forest -Municipal Solid

Waste (Management and Handling) Rules 2000

Directives:

Prohibit littering on the streets

Ensuring storage of waste at source in two bins; one for biodegradable waste and another for recyclable material.

Primary collection of biodegradable and non-biodegradable waste from the door step on a day- to-day.

Street sweeping.

Abolition of open waste storage bins.

Transportation of waste in covered vehicles

Treatment of biodegradable waste using composting or waste to energy technologies.

Minimize the waste going to the land fill.

Immediate steps to be taken

Stop unscientific dumping of waste at landfill sites. For this; Construct treatment facilities with capacities to

handle the present quantity collected.

Segregate waste into biodegradable, recyclable and inert fractions and only inert (non biodegradable) shall be land filled

Public awareness campaign to reduce waste quantity.

Promote recycling culture.

LONG TERM GOALS

Meet the guidelines of Municipal Solid Waste

(Management and Handling) Rules 2000

Improve the collection system to achieve 100 %

collection and add treatment capacity to handle

the entire waste quantity

Encourage community participation is essential

for smooth and efficient operation of SWM

system

Requirements of an effective Solid waste

Management program

Knowledge on Quantity and Characteristics of Waste

Efficient Collection network with complete coverage

Proper transportation of Waste

Fully equipped and well maintained Treatment/Recycling

facilities

Proper Disposal of Waste at land fill sites

Effective network for recycling and marketing of products

from solid waste treatment

Public awareness and Community Participation

Financial sustainability

Solid waste treatment – Available

technologies in use now

Composting

Vermicomposting

Anaerobic digestion / Biomethanation

Incineration

Gasification and pyrolysis

Plasma pyrolysis

Production of Refuse Derived Fuel (RDF) also known as pelletization and

Sanitary land filling/landfill gas recovery.

Conversion to bio-diesel

TREATMENT PROCESSES AN OVERVIEW

Biological Processes

Composting

Vermicomposting

Anaerobic digestion

Engineered Natural Process

Simple process and less capital

intensive

Minimum fuel (energy)

requirement

Complex process with high level

mechanization

High initial investment and

operation cost.

High energy input required

Physical Processes

Incineration

Chemical Processes

Gasification and pyrolysis

Plasma pyrolysis

Pelletization

BIOLOGICAL PROCESSES

Decomposition of Organic material by Microorganisms.

Two Types of process

1.Aerobic Process - By organism which requires oxygen

for respiration

Example - Composting

Organic Matter + O2 CO2 + H20 + New Cells (growth)

Complete Oxidation of Organic matters takes place

2.Anaerobic process – By organism which does not require

oxygen for respiration

Example – Anaerobic Digestion (Biogas plant)

Organic Matter CO2 + CH4 + H2S+ NH3 New Cells (growth)

Incomplete Oxidation of Organic matters resulting in formation of methane which on further oxidation acts as a fuel.

Composting

Composting is the most simple and a cost effective technology for treating the organic fraction of MSW

It is a well known process used by farmers since times immemorial.

Compost made out of urban heterogeneous waste is of higher nutrient value compared to the compost made out of cow dung and agro-waste.

It is a process in which organic material undergo biological degradation to a stable end product.

Microorganisms such as bacteria and fungi account for most of the decomposition.

Composting Process

Two Types of Composting Process

Windrow Composting

Box Composting

Allow passage of air and action of microorganisms for 6-7 weeks.

Garbage decomposes into stable end products

Heap the garbage in the form of windrows

Fill garbage in the boxes with holes for air entry

Comparison of Windrow & Box

composting

Particulars Windrow Composting Box Composting

Space

requirement

More space required Less space

requirement

Capital cost Less initial cost due to

lower infrastructural

requirements

Initial capital cost is

high

Operational

Manpower

requirement

Manpower required for

turning of Windrows

Requires less

manpower than

windrow composting

Operation of Composting Facility

Sorting

Mixing

Piling as windrows or filling in the box

Turning of Windrows (Not applicable for box composting)

Temperature Control

Moisture control

Maturing/ Curing

Screening

Storage and bagging

Vermicomposting

Worm composting is the process of culturing

worms to decompose organic waste.

This can be done indoors and outdoors, thus

allowing year round composting

Suitable for apartment dwellers also

Compost is made in a container filled with

moistened bedding and redworms.

vermi-composting is the preferred method at

house hold level and for small communities

Anaerobic Digestion or

Biomethanation

Biomethnation or Anaerobic Digestion (AD) is a the most commonly

used method of ‘Waste to Energy’ conversion

Solid waste with large proportion of organic matter is subjected to

decomposition in anaerobic condition, it produces a gaseous

mixture of CH4 (50- 60 %) and CO2.

This gas, known as bio-gas can be used for burning or for

generation of electricity.

The industrialization of AD began in 1859 with the first plant in

Bombay.

China and India are the front runner in popularizing this technology

for agro base small scale biogas plants

Now US & European Nations have acknowledged the importance of

Biogas as a source of Renewable energy.

Anaerobic Digestion Process

Steps of Digestion process • Hydrolysis • Acidogenesis • Acetogenesis • Methenogenesis

C6H12O6 → 3CO2 + 3CH4

General Process Description

Generally the overall AD process can be divided into four stages

Pretreatment

Sorting of waste and breaking into small pieces and adding required water

Waste digestion

Four step Process as explained in previous slide by Micro organisms.

Gas recovery

Gas generated collected and used as fuel

Residue treatment

The residue of Digestion (Digestate ) after dewatering can be used as Soil Conditioner like Compost

Process Diagram

Biogas

Anaerobic Digestion Process produce a much

valuable end product biogas compared to

composting process.

Initial investment and operating cost required for

anaerobic digestion plant for MSW is much higher

than that of Composting Plant.

Hence effective utilization of Biogas is very

important to make AD process financially atractive.

Biogas yield is up to 350 m3/ Ton of waste with a

calorific value of about 4000 kcal/m3

Electricity Generation from Biogas

About 100-150 kWh of Electricity can be generated per tone of waste input.

IC engines designed to burn propane or natural gas are easily converted to burn biogas by adjusting carburation and ignition systems

Two types of generators are used

Induction generators

Synchronous generators

Induction generators derive their phase, frequency and voltage from the utility

Synchronous generators operate as an isolated system or in parallel to the utility

Comparison of of Anaerobic Digestion

vs Composting

Particulars Anaerobic Digestion Composting

Space requirement

(footprint)

50% 100%

Emissions & Odours Low High (odours, Ammonia,

methane, nitrous oxide,

Hydrogen sulfide)

Energy balance Energy surplus Energy demand

Biogas production 100 – 150 m3/Mg Nil

Process time required

to produce mature

compost

3 weeks digestion, plus

5 weeks composting

12 weeks

Skilled Manpower Skilled manpower

required

Not required

Process upsets and

failure

Very strict monitoring

required operation.

Very rugged process

Hierarchy to be followed in Solid

Waste Management Program

Conclusions and Recommended

Options

Vermicomposting is preferred at individual house and small community level.

Composting is the simplest and cheapest method for medium level capacities.

It is the preferred process for panchayaths as it is less capital intensive and has less O&M requirements

Anaerobic digestion plants are suitable for large plants (Municipalities) as it requires less space.

A hybrid System comprising of Anaerobic Digestion Plant with Composting facility (for organic waste not easily digestible) will be a complete plant.

A effective network for marketing of Compost and recyclable items is very important.

In case of Power generation from biogas, the possibility of grid connection need to be studied.

THANK YOU