Aiga Kala ELLE-ADMS Odour 20120202

8/10/2019 Aiga Kala ELLE-ADMS Odour 20120202

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Odour modelling using

ADMS software

Presentation by

Dr David Carruthers

Cambridge Environmental Research Consultants(CERC)

Aiga Kla

Estonian, Latvian & Lithuanian Environment

(ELLE)


2/23

Overview

Odour units

Odour modelling and legal requirements

Practical examples


3/23

Odour units

Two types of odour units available inADMS:

ouA value in ou is aratio. The ou strength is the number oftimes the mixture must be diluted (at standard temperature

and pressure) to reach the detection limit

ouE(European odour unit)A value in ouEis amassmeasurement. One ouEis the mass of pollutant that, when

evaporated into 1m3 of odourless gas (at standard conditions)

results in a mixture with concentration equal to the detection

threshold for that pollutant

European odour units (ouE) are morecommonly used and olfactometry

measurements give odour concentrations in

ouE/m3


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Odour units (II)

The odour concentration of a compound can beestimated by:

D = C/T

Where:

D is the odour concentration of a compound

(dimensionless, odour units ouEm -3)

C is the chemical concentration of a

compound in mg m -3

Ta is the published odour threshold value of a

compound in mg m -3


5/23

How strong is an odour

unit?

According to generalised assumptions based

upon laboratory-based experiments on

perceived intensity: 1 ouE

m -3 is the point of detection

5 ouEm -3 is a faint odour

10 ouEm -3 is a distinct odour

The recognition threshold is often about

three odour units


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Lithuania User Group Meeting 2012

Modelling odours

Many types of installation have the potential for being the cause of

an odour nuisance problem

Waste water

treatment works

Landfill sitesLivestock farming

Paint spray

workshops

Fuel storage

ADMS-Urban and ADMS-Roads 3.1


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Modelling odours

ouE - The massof pollutant,

which when evaporated into

1m3of odourless gas at

standard conditions (STP)results in a mixture with

concentration equal to the

detection threshold for that

pollutant

Detection threshold - the point at which an increasing concentration of

an odour sample becomes strong enough to produce a first sensation

of odour in 50% of people to whom the sample is presented


Odours

appears as

new option in

Setup screen


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Modelling odours

Offensiveness

category

Indicative criterion(below which there is no

reasonable cause for

annoyance)

Examples of installation types

High 1.5 ouE/m3 Waste water treatment, brickworks, oil

refining

Medium 3 ouE/m3 Sugar beet processing, intensive

livestock rearing

Low 6 ouE/m3 Brewery, chocolate manufacture

Horizontal Guidance for Odour Management (H4)(Environment

Agency, April 2011): Classifies relative offensiveness of odours arising from different

types of process as High, Medium or Low

Odour exposure criteria expressed in terms of 98thpercentile of

hourly mean (equivalent to 175 exceedences per year)



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Modelling odours

Odours are not

included in the

default pollutants list,

so must be added to

the palette of

pollutants



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Modelling odours

This will produceoutput for direct

comparison with

the indicative

odour exposure

criteria.

The .gltoutput file contains thelong-term average

odour concentrations and percentiles of hourly

averageodour concentrations for all grid points.



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Modelling odours

Example- Odour release from a group of 5 vents:

Olfactometry 125 ouE/m3(STP) from each vent

Source characteristics:

Vent height: 1.75 m

Vent diameter: 1 m

Exit flow rate: 2 m3/s

Temperature: 15 C

Emission rate: 2 m3/s x 125 ouE/m3

= 250 ouE/s



12/23


Modelling odours

Offensiveness category Indicative criterion

High 1.5 ouE/m3

Medium 3 ouE/m3

Low 6 ouE/m3

Contour Plotter used to plot

98thpercentile of hourlyaverage odour concentrations

Comparing predicted odour

concentrations to indicative

odour exposure criteria:

No area of exceedence

for Low or Medium

offensiveness categories

Small area of

exceedence for High

offensiveness category



13/23

Legal requirements in Latvia

Cabinet of Ministers Regulations No 626adopted on July 27, 2004 Regulation on

the methods for determination of odour, as

well order of limitation of odours from

polluting activities

Odour target

value, ouEm -3

Percentile of

hourly averages

Source of odour

5 98.08th Not specified

8 98.08th Agricultural

activities

10 98.08th Permitted industrial

activities


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Examples emission rate

Emission factors from literature

pig farms (Environmental Protection Agency of

Ireland - Odour Impacts and Odour Emission

Control Measures for Intensive Agriculture, 2001)

Measurements the laboratory of LatvianEnvironment, Geology and Meteorology

Centre determine odour by means of

olfactometry

uploading oil products

pig farms

Calculated results based on odour threshold

values

uploading liquefied gas (methyl mercaptan)


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Measurements

Analytical techniques (chemical analysis)

Sensory methods (ie relating to the human

response) provides information on the

likely population response

Selection of a particular method will dependupon:

the purpose of the measurement

the frequency (once off or frequent/continuous) etc

the location at which the odour is sampled

whether a point source or surface/area source

the complexity of the emission - a single compound

or a complex mixture.


16/23

Case study fish processing


17/23

Case study fish processing (II)


18/23

Case study

fish processing (III)

Main production parameters:

Fish for drying - 7260 t/a

Fish for cooking 2324 t/a

Source characteristics:

Height: 23 and 11 m

Diameter: 400 and 500 mm

Exit flow rate:1200-1800 m3/h and 800

m3/h


19/23

Emission factors for fish

processing

Activity

Hydrogen

Sulfide (H2S),

kg/t

Trimethylamine((CH3)3N), kg/t

Fish cooking:

Fresh fish 0.005 0.15

Stale fish 0.1 1.75

Fish drying 0.05 n/d

AP 42, Fifth Edition, Volume I

Chapter 9: Food and Agricultural Industries


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Odour emissions

Odour tresholds:

For Hydrogen Sulfide 0.003 ppm(0.0042 mg/m3)

For Trimethylamine 0.48 ppm (1.16

mg/m3)

Activity

Odour

concentration,

(ouE/m3)

Odour

emission,

(ouE/s)

Fish drying 4690.48 1547.86Fish cooking,

H2S4773.81 1050.24

Fish cooking,

(CH3)3N

310.73 68.36


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Legend


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Odour assessment:

Oil product terminal,

Emission rate based on measurement results and information aboutodour treshold values


23/23

Odour assessment:

pig farm;

emission rate

calculated from EF

(odour units peranimal)

Documents

Aiga Kala ELLE-ADMS Odour 20120202