Odour Management 101 Wef2008
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Transcript of Odour Management 101 Wef2008
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Odour Management101
Presented by:
Anna H. Bokowa, M.Sc.ORTECH Environmental
Mississauga, OntarioCANADA
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OVERVIEW
• Odour Sampling Issues• How the Odour is Measured• Point Sources• Importance of Dilution Technique• Area Sources -which Method to Use?• Fugitive Sources• Ambient Sampling• Introduction to results using different Techniques• Conclusions
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• Methods are not standardized except for odour evaluation standard in Europe, Australia
• EN:13725:2003 “ Air Quality –Determination of Odour Concentration by Dynamic Olfactometry” is design more for evaluation of the already collected samples, not sampling
• Australia and New Zealand Standard – similar to European• Draft Ontario Ministry of Environment Method-Source Sampling for Odours, version 2, 1989
• No specific method for odour sampling in US except ambient measurement and
• A&WMA EE-6 Odor Committee – sub-committee called for development of draft odour sampling standard
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Odour Sampling Issues
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• Different odour sampling methods are used in different countries
• However most of countries agree with dilution technique especially when sampling at hot or humid sources
• Only in US it is a common practice to collect undiluted samples from these sources
• How important is dilution technique at these sources?
Odour Sampling Issues-con’t
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• How good are the analysis if the samples are not collected correctly?
• How anyone can Install a very expensive odour control equipment without a proper assessment of the facility
• Is it true well rounded annual condition established at facility when only one or two samples collected
• The accuracy of the results is limited when the number of samples is limited
Odour Sampling Issues (cont’d.)
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• Trend for municipal requests for proposal to specify analysis according to the European standard EN13725; 2003, but only one sample per source is defined just to reduce cost
• Most of the bids in Ontario are based on the lowest cost not quality of work
• Needs for proper odour assessment
• Needs for proer sampling methodology used in assessment
Odour Sampling Issues (cont’d.)
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• Proper sampling procedures especially for point sources when high in temperature and moisture content
• Proper sampling for area sources
• Number of samples per source
• Proper sampling for ambient locations
Odour Sampling Issues (cont’d.)
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• How good are the analysis if the samples are not collected correctly?
• Installation of very expensive odour control equipment without a proper assessment of the facility?
• Trend for municipal requests for proposal to specify analysis according to the European standard EN13725; 2003, but only one sample per source is defined
• The accuracy of the results is limited when the number of samples is limited
Odour Sampling Issues (cont’d.)
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• Different approaches for different sources
• Types of Sources: Point Sources- for example stacks, vents Area Sources-open piles, open tanks Fugitive Sources-windows, open doors, trucks
How the Odour Is Measured?
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• dilution technique• lung technique• flux chamber technique• wind tunnel technique
Sample Collection Procedures
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• Tedlar bags used for collection of samples• Other materials approved by European
standard • Residual odour from Tedlar, therefore a new
bag must be cleaned before use• Purging of the bags before collection• Importance of the volume of the sample• Sampling time• Number of samples per source• Performance (inlet/outlet) tests
Collection of the Samples
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• Importance of collecting more than one sample per source
• One sample per source- very common practice when issuing a request for proposal, even from municipalities when assessing odours at WWTP, rendering plants,
• Importance of testing under different process conditions
Number of Samples per Source
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• Odour sample diluted with nitrogen during sampling to prevent condensation, absorption and oxidation
• diluted sample collected at the temperature of the source
• pre-dilution test to calculate the optimum dilution level
• triplicate samples at each of four dilution levels (MOE requirement)
HeatedSampler
Probe
Nitrogen
Stack
TedlarGasBag
Dilution Sampling Technique
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Dynamic Pre-dilution Sampling
• odor samples collected using dilution sampling apparatus
• emission gases are diluted with nitrogen as the gases are extracted from the emission source
• nitrogen as a dilutant gas not air
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Predilution Ratio Determination
• collection of three samples at four different dilutions and calculation of the optimum dilution ( the highest ODTV)- MOE requirement
• analysis of the remaining two samples at the optimum dilution
• the geometric mean of the three samples at the optimum dilution is used for the emission rate calculation
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Is it time for Change in Procedure?
• Different times for different dilutions
• Possibly changes in process with time
• Ideally collect samples at different dilutions at the same time ( preferably two of three dilutions)
• Requires installation of minimum of 2 samplers at the same time at one source/stack
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Sampling at Point Sources
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Why Dilution is so Important?
To Prevent:
• condensation• adsorption of odours• chemical reactions such as oxidation
upon sample collection and cooling to ambient temperature
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Odor Sampler
• Based on the eductor• heated to the source temperature• range: 60 times to 8 times or
250 times to 60 times• calibrated with propane gas at different
temperature settings
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Lung Odour Sampler
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used for cold, low moisture sources, low in odour sources, ambient samples
Probe Pump
Stack
TedlarGasBag
Lung Technique
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Ambient Sampling using Lung Technique
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Results-Diluted Samples vs Undiluted
SamplingLocation
SampleNo. Predilution
Raw ODTV
(ou)
NetODTV
(ou)
Geometric MeanNet ODTV
(ou)
Source 1 1 50 651 32,550
2 50 668 33,400 34,294
3 50 742 37,100
1 40 636 25,440
1 60 336 20,160
1 1 2130 2,130
2 1 1969 1,969 2,075*
3 1 2130 2,130
*16X lower value
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Results-Diluted Samples vs Undiluted
SamplingLocation
SampleNo. Predilution
Raw ODTV
(ou)
NetODTV
(ou)
Geometric MeanNet ODTV
(ou)
Source 2 1 40 19 760
1 30 50 1,500
2 30 56 1,680 1,588
3 30 53 1,590
1 20 57 1,140
1 1 123 123
2 1 121 121 124*
3 1 128 128
*13X lower value
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Tedlargas bag
flux chamber
pump
flowmeter
sampling lungnitrogen cylinderbiofilterbiofilter
used for sampling at open sources (e.g., lagoons, storage piles)
Flux Chamber Technique
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Flux Chamber Sampler
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Area Source Sampling
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used for sampling of area sources
Wind Tunnel Technique
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ODTV-Thickener Vessel-Wind Tunnel MethodDate Sampled Sample Predilution Raw Odour Detection Net Odour Detection Geometric Mean
No. Ratio Threshold Value Threshold Value ODTVODTV ODTV
ou ou ou
August 3, 2006 Sample #1 1 724 724
Sample #2 1 845 845
Location 1 Sample #3 1 819 819
756
Location 2 Sample #1 1 724 724
Sample #2 1 709 709
Sample #3 1 724 724
Odour Emissio Rate = 61.99 ou/s/m 2
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ODTV-Thickener Vessel-Flux Chamber MethodDate Sampled Sample Predilution Raw Odour Detection Net Odour Detection Geometric Mean
No. Ratio Threshold Value Threshold Value ODTVODTV ODTV
ou ou ou
August 3, 2006 Sample 20X#1 20 985 19700
Sample 20X#2 20 826 16520
Location 1 Sample 20X#3 20 738 14760
19864
Location 2 Sample 20X#1 20 1158 23160
Sample 20X#2 20 1192 23840
Sample 20X#3 20 1158 23160
Odour Emission Rate = 5.19 ou/s/m 2
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Geometric EmissionMethod Pre-Dilution Mean of Rate Difference
OTV Samples ou/s/m2(ou)
Wind Tunnel None 760 6211 X
Flux Chamber 20 19,860 5.1
Wind Tunnel vs Flux Chamber Sampling
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• European- 13725 ; 2003 “Air Quality- Determination of Odour Concentration by Dynamic Olfactometry”
• Australian/New Zealand-AS/NZS 4323.3:2001-”Determination of Odour Concentration by Dynamic Olfactometry”
• ASTM 679-2004; “Standard Practice for Determination of Odor and Taste Threshold by Forced-Choice Ascending Concentration Series Method of Limits”; needs to be updated
• ASTM E544-2001; “Standard Practices for Referencing Superthreshold Odor Intensity”; needs to be withdrawn or replaced due to high exposure of n-butanol concentrations used for comparision ( 10 ppm to 20,000 ppm n-butanol in water)
• Draft AWMA EE-6-”Guideliness for Odor Sampling and Measurement by Dynamic Dilution Olfactometry”; needs to be updated
Standards for Odour Evaluation
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• emission rate (ou/s) - m3 basisOdour detection threshold value (ou)
x volumetric flowrate (m3/s)
• dispersion modelling
predicted concentration (ou) at receptors• exceedance of the 1 ou guideline may result in
the requirement for an odour emission reduction program
Odour Calculations
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• Lung sampling followed by dynamic olfactometry evaluation
• Portable Olfactometer – Scentometer or Nasal Ranger for Ambient Odour Investigation
Ambient Odour Sampling
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• upwind and downwind locations• a few locations chosen with the distance from
the facility• minimum three samples per location • sampling time depends on duration of
detectable odour• lung technique used for collection samples
Ambient Odour Sampling (Lung)
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Scentometer
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Nasal Ranger
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Portable Olfactometer
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Ambient Levels Based on AmbientSampling and Nasal Ranger Reading
Description
Ambient Level Based onAmbient Sampling
(ou)
Nasal RangerReadings
(DT)
Location 1 29 15
Location 2 12 7
Location 3 12 4
Location 4 8 <2
Location 5 9 2
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Conclusions
Loss of odour up to sixteen times by:• not using proper sampling • not diluting a sample at the source with
nitrogen • not heating a sampler to the source
temperature• not determining an optimum dilution• not preventing samples from direct sunlight
contact
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• Importance of the proper testing and analysis otherwise the loss of odour might be a significant and predicted off-site odours will be lower then the real ambient levels
• All sources should be assess not only point sources
• Caution should be used when some of the devices are used for ambient levels determinations
Conclusion-con’t
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Contact Information
Anna H. Bokowa, M.Sc.
Manager, Odour Assessment
ORTECH Environmental
1-877-774-6560, Ext. 669