Development of an odorant emission model for sewage treatment works

2001 ◽  
Vol 44 (9) ◽  
pp. 181-188 ◽  
Author(s):  
P. Gostelow ◽  
S.A. Parsons ◽  
J. Cobb
Keyword(s):  
Mass Transfer ◽  
Emission Rate ◽  
Sewage Treatment ◽  
Atmospheric Dispersion ◽  
Emission Sources ◽  
Emission Model ◽  
Emission Rates ◽  
Characteristic Emission ◽  
Atmospheric Dispersion Models ◽  
Odour Concentration

In the field of odour assessment, much attention has been paid to the measurement of odour concentration. Whilst the concentration of an odour at a receptor is a useful indicator of annoyance, the concentration at the source tells only half the story. The emission rate - the product of odour concentration and air flow rate - is required to appreciate the significance of odour sources. Knowledge of emission rates allows odour sources to be ranked in terms of significance and facilitates appropriate selection and design of odour control units. The emission rate is also a key input for atmospheric dispersion models. Given the increasing importance of odour to sewage treatment works operators, there is a clear need for predictive methods for odour emission rates. Theory suggests that the emission of odorants from sewage to air is controlled by mass transfer resistances in both the gas and liquid phase. These are in turn controlled by odorant and emission source characteristics. The required odorant characteristics are largely known, and mass transfer from many different types of emission sources have been studied. Sewage treatment processes can be described by one or more of six characteristic emission sources, these being quiescent surfaces, channels, weirs and drop structures, diffused aeration, surface aeration and flow over media. This paper describes the development of odorant mass transfer models for these characteristic emission types. The models have been applied in the form of spreadsheet models to the prediction of H2S emissions and the results compared with commercial VOC emission models.

Odour, covering and ventilation

2009 ◽  
Vol 59 (7) ◽  
pp. 1377-1384 ◽  
Author(s):  
D. Sivil ◽  
J. A. Hobson
Keyword(s):  
Mass Transfer ◽  
Emission Rate ◽  
Extraction Rate ◽  
Critical Flow ◽  
Residence Times ◽  
Minimum Rate ◽  
Maximum Value ◽  
Odour Concentration ◽  
Rate Of Extraction ◽  
Concentration Limits

A technique is described based on the decay in concentration of added SF6 to measure L0, the rate of leakage from an enclosure with no extraction of air. It is believed this measurement is much more precise than measurements of E0, the minimum rate of extraction which just prevents leakage. Three out of four enclosures studied had L0 values equating to residence times of air that were well under one hour. Relationships were developed between extraction rate and concentration and emission rate for enclosed odour sources based on mass transfer from water to air. These could be used to assess the benefits of minimising extraction rates while remaining within concentration limits set on the grounds of corrosion or toxicity. From these relationships a critical flow can be identified, termed Q50, at which both the emission rate and concentration of a particular species are at 50% of their maximum value. In any particular system, Q50 for one species, such as H2S, will in general not be the same as for another species, nor for odour concentration. As a consequence the benefit of reducing extraction rates based on H2S may not appear as good as it would based on an assessment of odour concentration. A second consequence is that as the rate of air extraction is varied, the ratio between two species or between H2S and odour concentration, is likely to vary.

scholarly journals Fundamentals of Odour Assessment in Slovenia

2020 ◽  
Vol 66 (11) ◽  
pp. 642-654
Author(s):  
Martin Dobeic ◽  
Vincenc Butala ◽  
Matjaž Prek ◽  
Jan Leskovšek ◽  
Žiga Švegelj
Keyword(s):  
Land Use ◽  
Atmospheric Dispersion ◽  
Temporal Distribution ◽  
Analytical Techniques ◽  
Ambient Air ◽  
Compliance Level ◽  
Atmospheric Dispersion Models ◽  
Impact Area ◽  
Odour Concentration ◽  
The Impact

From a sociological and economic perspective, odour pollution is one of the most complex problems in the field of air quality. Therefore, various approaches and odour impact criteria are particularly relevant when assessing odour exposure in the areas of different land use. The number of odour assessment methods is limited, and the lack of analytical techniques to determine odour concentration makes odour assessment even more complex. It is essential to analyse the spatial and temporal distribution of odour concentrations in order to assess odour nuisance in the ambient air. Since sampling of odorous air in the field for subsequent determination of odour concentrations in a laboratory by dynamic olfactometry is time-consuming, two approaches are used to assess odour concentrations in ambient air: estimating odour concentration by field inspection and calculation of odour concentrations using atmospheric dispersion models. The latter is the most commonly used technique. Our study aimed to provide fundamentals for an odour regulatory framework in Slovenia. While a multitude of approaches is presently applied to establish odour regulation framework, a broader approach remains lacking. Various odour emission sources were identified to evaluate available methods and techniques to assess odour impact. The impact area was selected to analyse and compare the impact of different odour sources in terms of odour concentration, odour frequency, odour offensiveness, land use, and receptor location. Finally, odour impact criteria were set according to odour offensiveness and concentration, percentile compliance level and land use.From a sociological and economic perspective, odour pollution is one of the most complex problems in the field of air quality. Therefore, various approaches and odour impact criteria are particularly relevant when assessing odour exposure in the areas of different land use. The number of odour assessment methods is limited, and the lack of analytical techniques to determine odour concentration makes odour assessment even more complex. It is essential to analyse the spatial and temporal distribution of odour concentrations in order to assess odour nuisance in the ambient air. Since sampling of odorous air in the field for subsequent determination of odour concentrations in a laboratory by dynamic olfactometry is time-consuming, two approaches are used to assess odour concentrations in ambient air: estimating odour concentration by field inspection and calculation of odour concentrations using atmospheric dispersion models. The latter is the most commonly used technique. Our study aimed to provide fundamentals for an odour regulatory framework in Slovenia. While a multitude of approaches is presently applied to establish odour regulation framework, a broader approach remains lacking. Various odour emission sources were identified to evaluate available methods and techniques to assess odour impact. The impact area was selected to analyse and compare the impact of different odour sources in terms of odour concentration, odour frequency, odour offensiveness, land use, and receptor location. Finally, odour impact criteria were set according to odour offensiveness and concentration, percentile compliance level and land use.

Olfactometric characterisation of sludge odours

2000 ◽  
Vol 41 (6) ◽  
pp. 49-55 ◽  
Author(s):  
S. D. Lambert ◽  
A. L. Beaman ◽  
P. Winter
Keyword(s):  
Recent Work ◽  
Sewage Treatment ◽  
Limited Information ◽  
Hedonic Tone ◽  
Detection Thresholds ◽  
Remediation Measures ◽  
Odour Concentration ◽  
Odour Profile ◽  
Storage Facilities

Conventional olfactometric techniques have been used to evaluate odours from sewage treatment and sludge storage facilities primarily in terms of odour concentration relative to their detection thresholds. However, such data conveys limited information that would be useful for determining the causes of most odours or the most appropriate remediation measures to be taken. Thispaper discusses some recent work undertaken to characterise the olfactometric profiles of different odours. Standard descriptive terms were used to characterise odours at normalised, moderately strong concentrations. These were used directly for the calculation of hedonic tone. They were also collated into a small number of generic odour groups and plotted to allow visual comparisons of different odour profile fingerprints. Such odour characterisations have proved to be very useful and may easily be incorporated into normal olfactometric evaluations.

scholarly journals Two Independent Light Dilution Corrections for the SO2 Camera Retrieve Comparable Emission Rates at Masaya Volcano, Nicaragua

2021 ◽  
Vol 13 (5) ◽  
pp. 935
Author(s):  
Matthew Varnam ◽  
Mike Burton ◽  
Ben Esse ◽  
Giuseppe Salerno ◽  
Ryunosuke Kazahaya ◽  
...  
Keyword(s):  
Light Scattering ◽  
Optical Depth ◽  
Camera Calibration ◽  
Wind Direction ◽  
Emission Rate ◽  
Emission Rates ◽  
Depth Images ◽  
Masaya Volcano ◽  
Rapid Changes ◽  
Volcanic Emission

SO2 cameras are able to measure rapid changes in volcanic emission rate but require accurate calibrations and corrections to convert optical depth images into slant column densities. We conducted a test at Masaya volcano of two SO2 camera calibration approaches, calibration cells and co-located spectrometer, and corrected both calibrations for light dilution, a process caused by light scattering between the plume and camera. We demonstrate an advancement on the image-based correction that allows the retrieval of the scattering efficiency across a 2D area of an SO2 camera image. When appropriately corrected for the dilution, we show that our two calibration approaches produce final calculated emission rates that agree with simultaneously measured traverse flux data and each other but highlight that the observed distribution of gas within the image is different. We demonstrate that traverses and SO2 camera techniques, when used together, generate better plume speed estimates for traverses and improved knowledge of wind direction for the camera, producing more reliable emission rates. We suggest combining traverses and the SO2 camera should be adopted where possible.

scholarly journals Photosynthesis and Related Physiological Parameters Differences Affected the Isoprene Emission Rate among 10 Typical Tree Species in Subtropical Metropolises

2021 ◽  
Vol 18 (3) ◽  
pp. 954
Author(s):  
Junyao Lyu ◽  
Feng Xiong ◽  
Ningxiao Sun ◽  
Yiheng Li ◽  
Chunjiang Liu ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Tree Species ◽  
Urban Areas ◽  
Emission Rate ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Single Species ◽  
Photosynthetic Parameters ◽  
Emission Rates ◽  
Isoprene Emission

Volatile organic compound (VOCs) emission is an important cause of photochemical smog and particulate pollution in urban areas, and urban vegetation has been presented as an important source. Different tree species have different emission levels, so adjusting greening species collocation is an effective way to control biogenic VOC pollution. However, there is a lack of measurements of tree species emission in subtropical metropolises, and the factors influencing the species-specific differences need to be further clarified. This study applied an in situ method to investigate the isoprene emission rates of 10 typical tree species in subtropical metropolises. Photosynthesis and related parameters including photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate, which can influence the emission rate of a single species, were also measured. Results showed Salix babylonica always exhibited a high emission level, whereas Elaeocarpus decipiens and Ligustrum lucidum maintained a low level throughout the year. Differences in photosynthetic rate and stomatal CO2 conductance are the key parameters related to isoprene emission among different plants. Through the establishment of emission inventory and determination of key photosynthetic parameters, the results provide a reference for the selection of urban greening species, as well as seasonal pollution control, and help to alleviate VOC pollution caused by urban forests.

scholarly journals Influence of the variability of the odour emission rate on its impact range: a case study of the selected industrial source

2019 ◽  
Vol 100 ◽  
pp. 00070 ◽  
Author(s):  
Elżbieta Romanik ◽  
Yaroslav Bezyk ◽  
Marcin Pawnuk ◽  
Urszula Miller ◽  
Agnieszka Grzelka
Keyword(s):  
Emission Rate ◽  
Dispersion Model ◽  
Grid Size ◽  
Model Calculations ◽  
Gas Treatment ◽  
Industrial Source ◽  
Odour Concentration ◽  
Made In ◽  
Dynamic Olfactometry

Odour concentration measurements in a chosen industrial source were made in this study using the method of dynamic olfactometry. The two different scenarios considered the variation of the odour emission rate as input for the dispersion model were compared for the period 2017 (before installation of the equipment for gas treatment) and 2018 (after implementation of purifying technologies). In this paper the odour impact range was determined by applying model calculations conducted in the Polish reference dispersion model – OPERAT FB software for the grid size 2 x 2 km. The conducted research shows a significant improvement in the odour impact range of chosen industrial source in year 2018 compared to 2017.

Odour Intensity Assessment at Different Area of a Palm Oil Mill Using Olfactometry Method

2015 ◽  
Vol 802 ◽  
pp. 472-477 ◽  
Author(s):  
Nurashikin Yaacof ◽  
Nastaien Qamaruz Zaman ◽  
Yusri Yusop
Keyword(s):  
Palm Oil ◽  
Emission Rate ◽  
Anaerobic Treatment ◽  
Cooling Pond ◽  
Intensity Assessment ◽  
Offensive Odour ◽  
Volatile Organic ◽  
Odour Concentration ◽  
Volatile Organic Acids ◽  
Palm Oil Mill

Malaysia is one of the world’s largest palm oil exporters, amounting to 39 % of world palm oil production and 44 % of world exports [1]. Palm oil mill usually engaged with odour problem that came from the wastewater treatment pond that released odourous compounds such as ammonia, volatile organic acids, and sulfides. This study was done to investigate odour nuisance from palm oil mill operations and odour emission rate at United Oil Palm (UOP) Mill, Nibong Tebal, Penang, Malaysia. Odour assessment was done on-site at four points and odour sample was taken from four anaerobic treatment ponds. Flux hood method was used and the samples were analysed by using the olfactometry method with six panels. It was found that in the UOP mill, the highest odour emission is from the anaerobic pond 2 with the average specific odour emission rate of 10.88 OUE/sm2, follow by cooling pond, acid pond and anaerobic pond 1. Besides knowing the main source of the odour, this study was run to find the intensity and offensiveness of the palm oil mill odour. A simple questionnaire was asked to the six panels about the odour intensity and odour offensiveness, and the average for both was at 5 (very strong odour) and 3 (definitely offensive odour). Higher level of offensiveness and intensity will increase the odour complaints, but by knowing those levels, it will help in deciding the limit of odour concentration that can be released and the threshold of odour that can be accepted by humans.

Log landings are methane emission hotspots in managed forests

2021 ◽  
Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Management Practices ◽  
Emission Rate ◽  
Woody Debris ◽  
Organic Matter Content ◽  
Growing Season ◽  
Matter Content ◽  
Emission Rates ◽  
Managed Forests

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.

scholarly journals Variations of the 630.0 nm airglow emission with meridional neutral wind and neutral temperature around midnight

2018 ◽  
Vol 36 (5) ◽  
pp. 1471-1481
Author(s):  
Chih-Yu Chiang ◽  
Sunny Wing-Yee Tam ◽  
Tzu-Fang Chang
Keyword(s):  
Emission Rate ◽  
Local Maximum ◽  
Neutral Wind ◽  
Emission Rates ◽  
Emission Layer ◽  
Neutral Winds ◽  
Neutral Temperature ◽  
Bright Spots ◽  
Different Temperatures ◽  
Volume Emission

Abstract. The ISUAL payload onboard the FORMOSAT-2 satellite has often observed airglow bright spots around midnight at equatorial latitudes. Such features had been suggested as the signature of the thermospheric midnight temperature maximum (MTM) effect, which was associated with temperature and meridional neutral winds. This study investigates the influence of neutral temperature and meridional neutral wind on the volume emission rates of the 630.0 nm nightglow. We utilize the SAMI2 model to simulate the charged and neutral species at the 630.0 nm nightglow emission layer under different temperatures with and without the effect of neutral wind. The results show that the neutral wind is more efficient than temperature variation in affecting the nightglow emission rates. For example, based on our estimation, it would require a temperature change of 145 K to produce a change in the integrated emission rate by 9.8 km-photons cm−3 s−1, while it only needs the neutral wind velocity to change by 1.85 m−1 s−1 to cause the same change in the integrated emission rate. However, the emission rate features a local maximum in its variation with the temperature. Two kinds of tendencies can be seen regarding the temperature that corresponds to the turning point, which is named the turning temperature (Tt) in this study: firstly, Tt decreases with the emission rate for the same altitude; secondly, for approximately the same emission rate, Tt increases with the altitude.

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