predicting odour

8/9/2019 Predicting Odour

1/9

Predicting odour emissions from wastewater treatment

plants by means of odour emission factors

Laura Capelli*, Selena Sironi, Renato Del Rosso, Paolo Cé ntola

Politecnico di Milano, Department of Chemistry, Materials and Chemical Engineering ‘‘Giulio Natta’’, Olfactometric Laboratory,

P.za Leonardo Da Vinci, 32 -20133 Milano, Italy

a r t i c l e i n f o

Article history:

Received 18 August 2008

Received in revised form

21 January 2009

Accepted 26 January 2009

Published online 4 February 2009

Keywords:

Wastewater treatment

Specific odour emission rate

Odour emission factors

Odour prediction

a b s t r a c t

In this study, the results of odour concentration measurements on different wastewater

treatment plants are presented and used in order to estimate the odour emission factors

relevant to single odour sources. An odour emission factor is a representative value that

relates the quantity of odour released to the atmosphere to a specific activity index, which

in this case was the plant treatment capacity, resulting in an odour emission factor

expressed in odour units per cubic metre of treated sewage. The results show that the

major odour source of a wastewater treatment plant is represented by the primary sedi-

mentation (with an OEF equal to 1.9 105 ouE m3). In general, the highest OEFs areobserved in correspondence of the first steps of the wastewater depuration cycle (OEF

between 1.1 104 ouE m3 and 1.9 105 ouE m3) and tend to decrease along the depu-ration process (OEF between 7.4 103 ouE m3 and 4.3 104 ouE m3). In general, the OEFscalculated according to this approach represent a model for a rough prediction of odour

emissions independently from the specific characteristics of the different plants.ª 2009 Elsevier Ltd. All rights reserved.

1. Introduction

Wastewater treatment plants (WWTPs) represent a common

source of odour emissions that can be the cause of odour

nuisance to the population living near, and problems con-

nected to odour emissions often represent the limiting factor

to the activity or construction of these kind of plants (Frechen,

1988; Gostelow et al., 2001).

Odours are emitted from waste water collection, treat-ment, and storage systems through volatilization of organic

compounds at the liquid surface. Odours in wastewater

treatment arise mainly from the biodegradation of sewage,

especially anaerobic degradation (Burgess et al., 2001), and

they are generated by a number of different wastewater

components (Vincent and Hobson, 1998), the most significant

being the sulphur compounds, hydrogen sulphide (H2S) and

mercaptan. Domestic sewage contains 3–6 mg l1 organic

sulphur, mainly arising from proteinaceous materials, plus

z4 mg l1 from sulphonates contained in household deter-

gents (Boon, 1995) and 30–60 mg l1 inorganic sulphur (as

sulphates) (Gostelow and Parsons, 2000).

Emissions can occur by diffusive or convective mecha-

nisms, or both. Diffusion occurs when organic concentrations

at the water surface are much higher than ambient concen-

trations. The organics volatilize (Bianchi and Varney, 1997), or

diffuse into the air, in an attempt to reach equilibriumbetween aqueous and vapour phases. Convection occurs

when air flows over the water surface, sweeping organic

vapours from the water surface into the air. The rate of vola-

tilization relates directly to the speed of the air flow over the

water surface (US EPA, 1995).

A useful tool for odour impact assessment and prediction

are odour emission factors (OEFs) (Sironi et al., 2005). OEFs are

developed in analogy with the emission factors defined by the

* Corresponding author. Tel.: þ39 02 23993206; fax: þ39 02 23993291.E-mail address: [email protected] (L. Capelli).

A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m

j o u r n a l h o m e p a g e : w w w . e l s e v i er . c o m / l o c a t e / w a tr e s

0043-1354/$ – see front matter ª 2009 Elsevier Ltd. All rights reserved.

doi:10.1016/j.watres.2009.01.022

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 5

mailto:[email protected]://www.elsevier.com/locate/watreshttp://www.elsevier.com/locate/watresmailto:[email protected]


2/9

United States Environmental Protection Agency (1995) for

other pollutants/chemical compounds, which relate the

quantity of a pollutant released to the atmosphere to a given

associated activity. In the estimation of OEFs for industrial

plants, these values can be calculated as the product of the

emitted odour concentration (ouE m3) by the emitted air flow

(m3 s1), divided by a specific index, which may be for example

the gross weight production, the site surface or a time unit.In general, OEFs can be used for odour impact assessment

as input data for the application of specific odour dispersion

models. OEFs also can have a predictive value: they allow to

estimate the odour emission rate (OER) associated with an

industrial plant even before its construction. Moreover, OEFs

may be applied in order to predict how the odour impact of an

industrial plant will be influenced by plant modifications, e.g.

for the case of WWTPs, the change of the conferred waste-

water quality or quantity, or the variation of the duration of

any treatment phase. In this case, OEFs can be useful in order

to evaluate the feasibility of the planned technological or

functional modifications (Sironi et al., 2006).

Data regarding the chemical concentration of pollutants,resulting from measurement campaigns on representative

sources, are generally available as a function of the processing

type and/or the fume depuration technology. On the other

hand, data found in literature concerning odour concentra-

tions and odour flow rates are few and with poor reliability.

This fact represents a serious limit for the availability of

‘‘bibliographical’’ OEFs and require that OEFs are created by

from experimental laboratory data.

This work describes the methods used for the calcula-

tion of OEFs based on the results of olfactometric

measurements that were carried out on a significant

number of WWTPs, which differ in constructional features,

in type of treated wastewater and in geographical locationsin Italy.

2. Materials and methods

2.1. Sampling

The major odour sources of a typical WWTP are represented

by the open-air wastewater treatment tanks, which can be

classified as area sources without outward flow (or passive

area sources) (Bockreis and Steinberg, 2005).

The sampling on area sources without outward flow

requires the use of specific hoods that have to be appropriatelydesigned in order to simulate the environmental conditions to

which the emitting surface is usually subject. The design and

the realization of a sampling system with such properties is

not banal and it is still under study (Frechen et al., 2004;

Hudson and Ayoko, 2008).

The data presented in this paper were obtained by using

a wind tunnel (WT) system, which enables the simulation of

wind action on the sampled surface ( Jiang et al., 1995; Jiang

and Kaye, 1996). The WT consists of a polyethylenete-

rephthalate (PET) hood that is positioned over the emitting

surface. A neutral air stream, either filtered through activated

carbon or coming directly from a synthetic air bottle, is

introduced at a known velocity inside the hood, simulating

the wind action on the liquid surface to be monitored. Air

samples are then collected in the outlet duct by means of

a vacuum pump.

Mass transfer from the monitored surface to the gaseous

phase is guaranteed by the air stream velocity (convective

mass transfer) (Bliss et al., 1995). This phenomenon can be

described according to the Prandtl boundary layer theory, and

the mass transfer coefficient calculated using the following expression:

Kc ¼0:664D

l Re1=2Sc1=3

where Kc is the mass transfer coefficient (m s1); D is the

molecular diffusivity of the odorous compounds in the liquid

phase; l is the length of the contact area between gaseous

phase and liquid phase in the air flow direction, i.e. the length

of the wind tunnel base; Re is the Reynolds number and Sc the

Schmidt number.

The wind tunnel (Fig. 1) used during the experimentation

has a circular section inlet and outlet duct, of 0.08 m diameter.

The central body of the hood used was a 0.25 m wide, 0.08 mhigh and 0.50 m long rectangular section chamber. Inside the

inlet duct there is a perforated stainless steel grid and inside

the divergentthat connects this duct to the central body of the

hood there are three flow deflection vanes. Both these devices

have the function of making the air velocity profiles as

homogeneous as possible.

In total, 211 samples were collected in 17 different plants

located all over Italy, treating mostly municipal wastewaters

and an amount of industrial wastewaters comprised between

10% and 25%, with a treatment capacity ranging from

a minimum of 1000 m3 day1 and a maximum of 80,0000 m3

day1.

2.2. Analysis

The olfactometric analyses were conducted in conformity

with the European norm EN 13725 (2003) in the Olfactometric

Laboratory of the Politecnico di Milano.

Dynamic olfactometry is a sensorial technique that allows

the determination of the odour concentration of an odorous

air sample relating to the sensation caused by the sample

directly on a panel of opportunely selected people. The odour

concentration is expressed in European odour units per cubic

metre (ouE m3), and it represents the number of dilutions

with neutral air that are necessary to bring the concentration

of the sample to its odour perception threshold concentration.The analysis is carried out by presenting the sample to the

panel at increasing concentrations by means of a particular

dilution device called olfactometer, until the panel members

start perceiving an odour that is different from the reference

neutral air. The odour concentration is then calculated as the

geometric mean of the odour threshold values of each pan-

ellist, multiplied by a factor that depends on the olfactometer

dilution step factor.

An olfactometer ECOMA model TO7, based on the ‘‘yes/

no’’ method, was used as a dilution device. This instrument

with aluminium casing has 4 panellist places in separate

open boxes. Each box is equipped with a stainless steel

sniffing port and a push-button for ‘‘yes’’ (odour threshold).

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 51978


3/9

The measuring range of the TO7 olfactometer starts from

a maximum dilution factor of 1:64,000, with a dilution step

factor 2. All the measurements were conducted within 30 h

after sampling, relying on a panel composed of 4 panellists.

The odour concentration was calculated as the geometric

mean of the odour threshold values of each panellist,

multiplied by ffiffiffi

2p

.

2.3. Calculation of OEFs

The OEF are developed with the aim of disposing of a simple

method forestimating the overall odour emission rate (OER) of

an industrial site (Sironi et al., 2005).

In WWTPs, odour emissions can be influenced by different

factors, such as wastewater composition, treatment methods

and treatment conditions (e.g. temperature, pH, retention

time, etc.). Since emission factors in general should have

a predictive and non-descriptive character (description of

plant emissions should be based on more specific data

regarding the above mentioned aspects), enabling a quick and

easyestimate of the overall emissions of a WWTP, theyshould

be expressed as a function of one possible ‘‘rough’’ aspect of

the considered plant. It was decided, in analogy with the

emission factors defined by the United States Environmental

Protection Agency (1995) for other pollutants/chemical

compounds, to refer the OEFs to a specific activity index,

which should be representative of the examined plant and

associated with the emitted odour quantity. In this study, the

average yearly treatment capacity was assumed as activity

index for WWTPs (Sironi et al., 2007). The appropriateness of

this choice is based on experimental evidence, which shows

the existence of a correlation between conferred wastewater

quantity and emitted odour quantity, and it is discussed in

Section 3.4.

The expression for the OEF calculation is therefore:

OEF ¼ OERC

where OEF is the odour emission factor in ouE m3, OER is the

odour emission rate in ouE year1 and C is the yearly treat-

ment capacity in m3 year1. The OEF therefore represents the

quantity of emitted odour related to the wastewater volume

unit, i.e. it is expressed in odour units per cubic metre of

treated sewage.

The OEF must be evaluated separately for each plant, and

for each odour source, considering that each odour source is

represented by the single treatment phases of the depuration

cycle. The odour sources that were considered for this study

are:

Wastewater arrival (WW-arr); Pre-treatments (pre-tr); Primary sedimentation (I-sed); De-nitrification (denitr);

Nitrification (nitr); Oxidation (oxi); Secondary sedimentation (II-sed); Chemical-physical treatments (ch-ph); Sludge thickening (sl-thi); Sludge storage (sl-st).

Some considerations have to be made as far as the above

mentioned odour sources are concerned. These sources are

area sources without outward flow (passive area sources),

whereliquid(orsolid)surfaceisexposedtoatmosphericagents

and perturbations, and emissions occur directly to the atmo-

sphere without any containment possibility. For these kind of

sources the evaluation of the OER requires the calculation of a parameter called specific odour emission rate (SOER), which

is expressed in ouE s1 m2 and can be obtained by multiplying

the odour concentration measured at the outlet of the wind

tunnel (ouE m3) with the flow rate of the inlet air (m3 s1) and

dividing it bythe baseareaof the centralbodyof thehood (m2).

The OER is then calculated as the product of the SOER and the

emitting surface (m2) of the considered area source.

Based on itsdefinition, the SOER is a function of theneutral

air stream velocity that is introduced into the wind tunnel. As

during field measurements samplings are not always con-

ducted at the same conditions, the SOER values are evaluated

for each sampling separately, considering the sampling

conditions, e.g. neutral air stream velocity, that were adoptedcase by case. The SOER values are then normalized to a refer-

ence velocity of 0.3 m s1 (Bliss et al., 1995) using the following

equation, which is derived directly from the Prandtl boundary

layer theory (Sohn et al., 2005):

SOERv2 ¼ SOERv1

v2v1

1=2

The emitting surface (e.g. dimensional characteristics of the

wastewater treatment tanks) relevant to some of the consid-

ered odour sources were not available. In these cases, the

emitting surfaces had to be estimated according to the criteria

forthe design of wastewater treatment plants (Tchobanoglous

and Burton, 1991).

Fig. 1 – Design of the wind tunnel.

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 5 1979


4/9


5/9

of the OEFs relevant to each of the odour sources that are

present at the considered plant. As an example, if a WWTP

is constituted by all the treatment phases that were

considered as odour sources in this study, its overall

OER could be determined according to the following

equation:

OERTOT ¼ C

OEFWW-arr þOEFpre-tr þOEFI-sed þOEFdenitrþOEFnitr þOEFoxi þOEFII-sed þOEFch-ph þOEFsl-thiþOEFsl-st

where C is the plant treatment capacity (e.g. in m3 day1) and

the OEF are expressed in ouE m3

. The index indicates theodour source which the OEFs refer to.

The equation that allows the determination the overall

OER, once the plant capacity is given, was obtained by

substituting the OEFs values that were calculated in this

study:

OERTOT ¼C

1:1 104 þ 1:0 105 þ 1:9 105 þ 9:2 103

þ 7:4 103 þ 1:2 104 þ 1:3 104 þ 8:2 103

þ 4:2 104 þ 8:3 103

OERTOT ¼ C 4:07 105

As an example, the overall OER relevant to a plant with an

average treatment capacity of 50,000 m3 day1 may be calcu-

lated according to the proposed model.

In this specific case, the overall OER would be:

OERTOT ¼50; 000

1:1 104 þ 1:0 105 þ 1:9 105 þ 9:2 103þ 7:4 103 þ 1:2 104 þ 1:3 104 þ 8:2 103

þ 4:2 104 þ 8:3 103

OERTOT ¼ 50; 000 m3 day1 4:07 105 ouE m3

¼ 2:04 1010 ouE d1 ¼ 2:36 105 ouE s1

10

100

1000

10000

100000

100 1000 10000 100000 1000000

Treatment capacity C (m3 d-1)

O d o u r c o n c e n t r a t i o n c o d ( o u E m - 3 )

Geometric mean = 845 ouE m

-3

Fig. 2 – Odour concentration values relevant to the sludge storage.

Table 3 – Arithmetic mean, median and standarddeviation of the logarithms of the OEFs

Arithmetic

meanof log(OEF)

Median of

log(OEF)

Standard

deviationof log(OEF)

Wastewater arrival 4.036 3.488 1.405

Pre-treatments 5.021 5.534 1.429

Primary

sedimentation

5.280 5.072 0.854

De-nitrification 3.962 3.797 0.631

Nitrification 3.866 3.840 0.848

Oxidation 4.082 4.236 0.790

Secondary

sedimentation

4.118 4.120 0.524

Chemical–physical

treatments

3.916 4.035 0.587

Sludge thickening 4.629 4.698 0.894

Sludge storage 3.917 4.009 0.701

Table 4 – Average OEFs, median and percent deviation

Geometricmeanof OEF

Median of OEF %Deviation

Wastew ater arrival 1.09Eþ04 3.09Eþ03 40Pre-treatments 1.05Eþ05 3.42Eþ05 26Primary sedimentation 1.90Eþ05 1.18Eþ05 17De-nitrification 9.15Eþ03 6.27Eþ03 17Nitrification 7.35Eþ03 6.91Eþ03 22Oxidation 1.21Eþ04 1.72Eþ04 19Secondary

sedimentation

1.31Eþ04 1.34Eþ04 13

Chemical–physical

treatments

8.25Eþ03 1.09Eþ04 15

Sludge thickening 4.25Eþ04 4.99Eþ04 19Sludge storage 8.26E

þ03 1.02E

þ04 17

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 5 1981


6/9

If any of the steps are carried out in closed sheds with an aircollection system that conveys the waste gases to an abate-

mentsystem, the effective OER of the plant mustbe calculated

taking account of the odour abatement efficiency of the

adopted abatement system (Sironi et al., 2006).

3.4. Influence of plant size on odour emissions

In order to evaluate the influence of the size of a WWTP on its

dour emissions, the data used for the OEF calculation were re-

processed by dividing thembased on the plant size. The plants

considered as ‘‘small’’ are the ones with a treatment capacity

within 103 and 104 m3 day1, ‘‘medium’’ within 104 and 105 m3

day1 and ‘‘large’’ within 105 and 106 m3 day1.Fig. 4 shows the average odour concentration values

(geometric mean) for each examined odour source relevant to

the three plant sizes. It can be observed that, if considering the

same treatment phase, there are no significant differencesbetweenthe average odour concentration values measured on

small, medium, or large size plants.

This fact entails some interesting consequences for the

correlation between the odour emission rates from the

different treatment phases and the plant size.

First, the SOER values relevant to each odour source, being

derived directly from the measured odour concentrations, are

similar independently from the considered plant capacity.

This means that SOER values could be used in order to

calculate odour emissions from a proposed WWTP. None-

theless, the direct use of SOER values for overall OER estima-

tion entails the necessity to consider each treatment phase

separately and to have precise information about each odoursource. Such information may not be available, especially in

the case of a plant that does not already exist, moreover,

calculations would be more difficult with respect to the

1.09E+04

1.05E+05

1.90E+05

9.15E+037.35E+03

1.21E+04 1.31E+048.25E+03

4.25E+04

8.26E+03

1.00E+03

1.00E+04

1.00E+05

1.00E+06

W a s

t e w a t e

r a r r i v

a l

P r e - t

r e a t m

e n t s

P r i m

a r y s

e d i m

e n t a t

i o n

D e - n i t r i f

i c a t i o

n

N i t r i f

i c a t i o

n

O x i d a

t i o n

S e c o

n d a r

y s e d

i m e n

t a t i o n

C h e m

i c a l - p

h y s i c

a l t r e

a t m e n

t s

S l u d

g e t h i c k

e n i n g

S l u d g

e s t o r

a g e

O E F ( o u E m - 3 )

Fig. 3 – Average OEFs for each considered odour source.

1.00E+01

1.00E+02

1.00E+03

1.00E+04

W a s

t e w a t e

r a r r i

v a l

P r e - t

r e a t m

e n t s

P r i m

a r y s e

d i m e n

t a t i o n

D e - n i

t r i f i c a

t i o n

N i t r i f

i c a t i o

n

O x i d a

t i o n

S e c o

n d a r y

s e d i m

e n t a t

i o n

C h e m

i c a l - p

h y s i c

a l t r e

a t m e n

t s

S l u d g

e t h i c

k e n i n

g

S l u d

g e s t o r a

g e

c o d ( o

u E m - 3 )

Small

Medium

Large

Fig. 4 – Average odour concentration relevant to each treatment phase for small, medium and large plants.

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 51982


7/9

possibility of using of OEFs, which are useful in order to give

a quick estimationin function of a single parameter (i.e. in this

case the plant capacity).

Finally, looking at Figs. 5 and 6, which illustrate the OER

values and the OEFs in function of the plant size, respectively,

the following considerations can be made.

Some treatment phases, such as the primary sedimenta-

tion, the oxidation and the secondary sedimentation, require

an optimal residence time and tank deepness. These phases

are therefore characterized by an emitting surface (i.e. the

tank surface) that is proportional to the plant capacity andconsequently by odour emissions that increase proportionally

to the plant size. On the other hand, for those treatment

phases for which no direct relationship between the emitting

surface and the plant treatment capacity exists (such as the

wastewater arrival, pre-treatments, de-nitrification, nitrifica-

tion, sludge thickening and sludge storage), the odour emis-

sion rates will be similar independently from the plant size

(Fig. 5).

The opposite consideration is valid if considering the OEFs.

Given that the OEFs for WWTPs have been defined as the ratio

between the OER values and the plant capacity, the OEFs

related to the treatment phases whose emitting surface is

proportional to the plant capacity will be similar indepen-

dently from the plant size, whereas the OEFs relevant to odoursources whose emitting surface is independent from the plant

capacity will decrease passing from small to larger plants

(Fig. 6).

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

W a s

t e w a t e

r a r r i v

a l

P r e - t

r e a t m

e n t s

P r i m

a r y s e

d i m e n

t a t i o n

D e - n i

t r i f i c a

t i o n

N i t r i f

i c a t i o

n

O x i d a

t i o n

S e c o

n d a r y

s e d i m

e n t a t

i o n

C h e m

i c a l - p

h y s i c

a l t r e

a t m e n

t s

S l u d g

e t h i c

k e n i n

g

S l u d g

e s t o r

a g e

O E R

( o u E s - 1 )

Small

Medium

Large

Fig. 5 – Average odour emission rates relevant to each treatment phase for small, medium and large plants.

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

W a s

t e w a t e

r a r r i v

a l

P r e -

t r e a t m

e n t s

P r i m

a r y s

e d i m

e n t a t

i o n

D e - n i t r i

f i c a t i

o n

N i t r i f

i c a t i o

n

O x i d a

t i o n

S e c o

n d a r

y s e d

i m e n

t a t i o n

C h e m

i c a l - p

h y s i c

a l t r e

a t m e n

t s

S l u d g

e t h i c

k e n i n

g

S l u d g

e s t o r

a g e

O E F ( o

u E m - 3 )

Small

Medium

Large

Fig. 6 – Average OEFs relevant to each treatment phase for small, medium and large plants.

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 5 1983


8/9

4. Conclusions

Based on the discussed results it is possible to list the

following conclusions.

- This paper discusses an approach for the creation of

a model for a rough and simple prediction of the odouremissions from a WWTP from experimental data, i.e.

from the results of olfactometric analyses conducted on

several Italian WWTPs.

- Considering the same odour source, a similarity among

the odour concentration values measured on the different

WWTPs is noticeable, independently from their size. This

similarity has interesting consequences on the odour

emission rates from the different phases, based on the

whether the emitting surface of the considered phase is

proportional to the plant size (i.e. treatment capacity) or

not.

- The obtained results show that the major odour source of

a WWTP is represented by the primary sedimentation,having an OEF of about 1.9 105 ouE m3. In general thehighest OEFs are observed in correspondence of the first

steps of the wastewater depuration cycle: this demon-

strates that the odour load of wastewater prior to biolog-

ical treatment is rather high (OEF between 1.1 104 ouEm3 and 1.9 105 ouE m3), tending to decrease along thedepuration process (OEF between 7.4 103 ouE m3 and4.3 104 ouE m3). This fact points out the importance of the sewer system, which influences the quality of the

wastewater at the plant inlet and therefore its odour

emission capacity (Frechen, 2008). For this reason, the

operating conditions of the wastewater treatment plant

itself generally have lower influence on odour emissionsfrom the first treatment steps than the correct manage-

ment of the sewer system, which is often referred to as

a subject that is different from the wastewater treatment

plant management.

- An indication of the margin of error introduced in the OEF

calculation is given by the standard deviations of the

odour concentration measurements of the different odour

sources (Table 1). The effectiveness of the OEFs is not

compromised by such errors, as OEFs must be useful for

an estimation of a plant total odour impact.

- The OEFs should be updated continuously, for example by

adding more data from further olfactometric analyses.

This procedure may be facilitated by creating an elec-tronic database for the insertion or variation of useful

data for the OEF calculation.

- The precision of the OEFs can be improved by first veri-

fying the applicability of this model with accurate data-

sets describing the actual conditions on site. The OEFs

may be further refined and the margin of error associated

with theuse of OEFs for the prediction of the odour impact

caused by a WWTP may be reduced by evaluating their

dependence from other parameters that were not

considered in this study, such as for example BOD,

temperature or humidity.

- According to their definition, OEFs enable a simple and

quick quantitative estimation of odour emissions,

without taking into account odour quality, which

nonetheless might represent an important aspect to

be considered for odour impact and nuisance

evaluation.

r e f e r e n c e s

Bliss, P.J., Jiang, J.K., Schulz, T.J., 1995. The development of a sampling system for determining odor emission rates fromarea surfaces: part II. Mathematical model. Journal of the Air &Waste Management Association 45, 989–994.

Bockreis, A., Steinberg, I., 2005. Measurement of odour with focuson sampling techniques. Waste Management 25, 859–863.

Boon, A.G., 1995. Septicity in sewers: causes, consequences andcontainment. Water Science and Technology 31, 237–253.

Burgess, J.E., Parsons, S.A., Stuetz, R.M., 2001. Developments inodour and waste gas treatment biotechnology: a review.Biotechnology Advances 19, 35–63.

EN 13725, 2003. Air Quality – Determination of OdourConcentration by Dynamic Olfactometry. Comité Européen deNormalisation, Brussels.

Frechen, F.B., 1998. Odour emissions and odour control atwastewater treatment plants in West Germany. Water Scienceand Technology 20, 261–266.

Frechen, F.B., Frey, M., Wett, M., Lo ¨ ser, C., 2004. Aerodynamicperformance of a low-speed wind tunnel. Water Science andTechnology 50 (4), 57–64.

Frechen, F.B., 2008. Emission of odours from sewer systems:possible countermeasures of their efficiency using the odouremission capacity OEC. In: Del Rosso, R. (Ed.), ChemicalEngineering Transactions, vol. 15. AIDIC Servizi S.r.l., Milano,Italy, pp. 183–190.

Gostelow, P., Parsons, S.A., 2000. Sewage treatment works odour

measurement. Water Science and Technology 41, 33–40.Gostelow, P., Parsons, S.A., Stuetz, R.M., 2001. Odour

measurements for sewage treatment works. Water Research35, 579–597.

Hudson, N., Ayoko, G.A., 2008. Odour sampling. 2. Comparison of physical and aerodynamic characteristics of sampling devices:a review. Bioresource Technology 99, 3993–4007.

Jiang, J.K., Bliss, P.J., Schulz, T.J., 1995. The development of a sampling system for determining odor emission rates fromarea surfaces: part I. Aerodynamic performance. Journal of theAir & Waste Management Association 45, 917–922.

Jiang, J.K., Kaye, R., 1996. Comparison study on portable windtunnel system and isolation chamber for determination of VOCs from area sources. Water Science and Technology 34(3-4), 583–589.

Sironi, S., Capelli, L., Céntola, P., Del Rosso, R., Il Grande, M., 2005.Odour emission factors for the assessment and prediction of Italian MSW landfills odour impact. AtmosphericEnvironment 39 (29), 5387–5394.

Sironi, S., Capelli, L., Céntola, P., Del Rosso, R., Il Grande, M., 2006.Odour emission factors for the prediction of odour emissionsfrom plants for the mechanical and biological treatment of MSW. Atmospheric Environment 40 (39), 7632–7643.

Sironi, S., Capelli, L., Céntola, P., Del Rosso, R., Il Grande, M., 2007.Odour emission factors for assessment and prediction of Italian rendering plants odour impact. Chemical Engineering

Journal 131 (1-3), 225–231.Sohn, J.H., Smith, R.J., Hudson, N.A., Choi, H.L., 2005. Gas

sampling efficiencies and aerodynamic characteristics of a laboratory wind tunnel for odour measurement. Biosystems

Engineering 92 (1), 37–46.

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 51984


9/9

Tchobanoglous, G., Burton, F.L., 1991. WastewaterEngineering: Treatment. Disposal and Reuse. McGraw-Hill,New York.

Vincent, A., Hobson, J., 1998. Odour Control. CIWEM Monographson Best Practice No. 2. CIWEM, London, UK.

United States Environmental Protection Agency (US EPA), 1995.Waste water collection, treatment and storage. In:Compilation of Air Pollutant Emission Factors, AP-42, fifth ed.,vol. I. Stationary Point and Area Sources, 4.3. US EPA, ResearchTriangle Park, NC, pp. 1–46.

w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 1 9 7 7 – 1 9 8 5 1985

predicting odour

Documents