Odour Emission Rate Research Articles

Temporal Variation of White Rhino Dung Odours.

In order for an olfactory signal to be effective, it must persist in the environment for an extended period. White rhino dung odours transmit information about sex, age, territorial and oestrous states. As these odours relay important information, temporal changes in the odour emission rate and/or composition may be critical in order for other individuals to obtain this information. Here, we examine how the dung odours of adult white rhinos (male: territorial and non-territorial; female: oestrous and non-oestrous) change over the short (hours) and long (seasons) term using headspace extraction. Additionally, we measure seasonal midden visitation and defecation frequency to link behaviours to seasonal changes in odour longevity. We found that during the dry season, territorial male dung odours persisted for 48 hours, while the odours of all other adults persisted for >48 hours. The high temperature and humidity of the wet season did not affect odour longevity of oestrous females, but decreased dung odour longevity (i.e. increased emission) of territorial males, non-territorial males, and non-oestrous females. Despite this reduction, neither males nor females adjusted their seasonal visitation or defecation frequency. With regard to a temporal indicator, 3,7-dimethly-1,6-octadiene signalled dung age during the wet season, while acetophenone signalled dung age during the dry season. Ultimately, our results provide the first detailed account of temporal changes of dung VOCs, and highlight the limitations of dung as a signalling medium.

Chemometric analysis and NIR spectroscopy to evaluate odorous impact during the composting of different raw materials

This study evaluated odor generated during the first stage of the composting process in a dynamic respirometer using different raw materials such as the organic fraction of municipal solid waste (OFMSW), a mixture of this organic fraction with orange peel waste (OFMSW-OPW), sewage sludge with bulking agent (SL) and a mixture of strawberry extrudate, fish waste, sewage sludge and bulking agent (SFWSL). The combination of near infrared reflectance (NIR) spectroscopy and chemometric analysis is proposed to correlate the chemical composition and the operational variables of each raw material to odor generated during the composting process. The operational variables temperature, dynamic respirometric index (DRI), airflow (Q), odor concentration (OC) and odor emission rate (OER) were monitored. Adequate linear correlations were obtained between temperature and DRI for each compostable substrate within a confidence interval of 10% and 30%. Operational variables were statistically analyzed by principal component analysis with 87% of total variance explained and from which the substrates were clearly grouped. Near infrared reflectance spectroscopy provided the chemical composition of each raw material, and was found to be an advantageous technique to predict the relationship between odor emissions and absorption bands. Odor emissions were also predicted from the operational variables by multivariate regression, with temperature and DRI being the most influential variables.

Estimation of odor emission rate from swine nursery facilities using probability distribution

Estimation of odor emission rate from swine nursery facilities using probability distribution

Centralized management of sewage sludge and agro-industrial waste through co-composting

In this research study, the co-composting process of a waste mixture containing strawberry extrudate, fish waste, sewage sludge and bulking agent (SEFW, 190:1:22:90 ratio) was carried out in a dynamic-solid respirometer at pilot scale. The aerobic biodegradability of the mixture was previously ensured in a static-liquid respirometer. The advantages and drawbacks of the SEFW co-composting process were subsequently identified through the determination of respirometric activity and the physical-chemical characterization of the waste, as well as the monitoring of odor emissions. The evolution of the physical-chemical variables showed that pH increased slightly and that the organic matter concentration, expressed as volatile solids (VS, %) or oxidable organic carbon (COXC, %), decreased by around 15% in both cases and by approximately 56% in its biodegradable form (total organic carbon, TOC, %). The low odor emission rate (OER) in the least favorable scenario (the maximum odor generation) during SEFW composting was 1.59 ouE/s, whereas this figure reached 3.52 ouE/s when only the organic fraction of municipal solid waste (OFMSW) was composted. Consequently, the co-composting of SEFW is more favorable in terms of odor emission and permits the simultaneous treatment of different types of waste.

Proposal of Odor Nuisance Index as Urban Planning Tool.

This article analyzes the state of the art of the methods and models used for the characterization of odor annoyance and it preliminary advances some proposals for the evaluation of the olfactory nuisance. The use of a sensorial technique, such as dynamic olfactometry, is proposed for the analysis of odor concentrations, odor emission rates, and odor dispersions. A simple model for the quantification of environmental odor nuisance, based on the use of FIDOL factors, that are, frequency, intensity, duration, hedonic tone, and location, is proposed.

Comparison of different approaches for the estimation of odour emissions from landfill surfaces

The aim of this study is related to the assessment of odour emissions from landfill surfaces. Up to now, there is not a widely accepted method to quantify odour emissions from this particular kind of source. Five different methods were developed and investigated. These methods can be considered as based on three distinct approaches, both experimental and computational. The first approach provides to use models for the estimation the landfill gas production, whereby the second and the third approach are based on direct measurement campaigns on the landfill surface: for the determination of the methane concentration or for the direct measurement of the odour concentration, respectively. The methods were then compared in terms of specific odour emission rates by referring to other literature data. Finally, dispersion modelling was applied in order to allow a further comparison of the resulting odour impacts with other olfactometric data from independent monitoring campaigns on the studied site.

Environmental Odour Impact Assessment of Landfill Expansion Scenarios: Case Study of Borgo Montello (Italy)

One of the most reliable methods for the prediction of odour impact from environmental facilities, strongly influenced by topography and local atmospheric dynamics, involves the use of atmospheric dispersion models.The present study focuses on the implementation of a dispersion model for the prediction of odour impact from a large and complex landfill system, localized in Borgo Montello (Latina), in the Lazio Region (Central Italy). The Calpuff dispersion model was selected for the simulations of odour impact, since it is well recognized as the preferred model for assessing the long range transport of pollutants. The odour emission rates, which are the inputs to the dispersion model, were defined on the basis of dynamic olfactometric analyses on air samples taken in the landfills areas. Different scenarios were simulated, with the aim of evaluating the odour impact caused by a project of landfill expansion through height raise. The environmental odour impacts were assessed through the evaluation of the area which would be impacted by odour emissions due to the implementation of the expansion project, in comparison to the actual air quality conditions with no further control measures. This one allowed for quantifying the alteration of the environmental quality state as well as designing the systems and interventions to be implemented to reduce the odour in the impacted area of the surroundings.

Evaluation of an Odour Emission Factor (OEF) to estimate odour emissions from landfill surfaces

Emission factors are fundamental tools for air quality management. Odour Emission Factors (OEFs) can be developed in analogy with the emission factors defined for other chemical compounds, which relate the quantity of a pollutant released to the atmosphere to a given associated activity. Landfills typically represent a common source of odour complaint; for this reason, the development of specific OEFs allowing the estimation of odour emissions from this kind of source would be of great interest both for the landfill design and management. This study proposes an up-to-date methodology for the development of an OEF for the estimation of odour emissions from landfills, thereby focusing on the odour emissions related to the emissions of landfill gas (LFG) from the exhausted landfill surface. The proposed approach is an “indirect” approach based on the quantification of the LFG emissions from methane concentration measurements carried out on an Italian landfill. The Odour Emission Rate (OER) is then obtained by multiplying the emitted gas flow rate by the LFG odour concentration. The odour concentration of the LFG emitted through the landfill surface was estimated by means of an ad hoc correlation investigated between methane concentration and odour concentration. The OEF for the estimation of odour emissions from landfill surfaces was computed, considering the landfill surface as the activity index, as the product between the mean specific LFG flux emitted through the surface resulting from the experimental campaigns, equal to 0.39 l/m2/h, and its odour concentration, which was estimated to be equal to 105′000 eq. ouE/m3, thus giving an OEF of 0.011 ouE/m2/s. This value, which is considerably lower than those published in previous works, should be considered as an improved estimation based on the most recent developments of the research in the field of odour sampling on surface sources.

Limiting Odour Emission from Piggery through Application of Heat Recovery System

Abstract The aim of the study was to determine the effect of manure cooling by the use of the heat recovery system on odour emission from a deep litter piggery. Annual comparative research was carried out in a twin-room deep litter piggery located in Wielkopolska Voivodeship. The recovered heat was transferred to central heating and domestic hot water systems of a residential building. The study showed that the average odour emission rate from the room, where heat was recovered (0.192±0.083 ouE·s−1·kg m.c.−1) was lower than in the room without heat recovering (0.273±0.138 ouE·s−1·kg m.c. −1) (p<0.05). The difference was 27%. It was also found that there was statistically significant strong correlation (r =0.86) between the amount of the recovered heat and the percentage odour emission reduction (p <0.05). This relationship was described by the logarithmic regression line y=12.5ln(x)-21.5 (r2=0.74)

악취 배출구의 합리적인 배출규제를 위한 사례연구

In this study, field experiment, odor simulator, and dispersion modeling were used to evaluate the odor impact from J sewage sludge treatment facility. The height and flow rate of exhaust stack at this facility were 22.3 m and . The mean odor concentrations of the wet scrubber inlet and exhaust stack were and , respectively. The odor removal efficiency of wet scrubber showed 65%. The odor simulator is used for the regulated standard calculation of the exhaust pipe(stack). Resulting odor emission rate(OER) by odor simulator was . The forecasting result by Screen3 modeling showed that odor exhaust concentration up to was't exceeded maximum allowable emission level on site boundary().

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

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.

Modelling of Odour Emission Rates for Fattening Pigs as Time-resolved Input for Dispersion Models

For the calculation of the separation distance to avoid odour annoyance, the odour emission rate of the livestock building has to be known as input for the dispersion model. In general, an annual mean value is used although the influence of the live mass growth of the animals as well as of indoor air temperature and ventilation rate on the emission rate is known. This simplified approach was compared with various emission scenarios for a continuous fattening system with a constant live mass of 75 kg and an all-in/all- out system. For the last one a Monte-Carlo based model (inverse transfer sampling technique) was used to avoid an interaction between the growth of the animals and the annual variation of the outdoor temperature. The variation of the emission factor was taken into account twofold, first by a schematized diurnal emission pattern for the various seasons and second by a steady state simulation of the indoor climate to calculate indoor temperature and ventilation rate which both influence the odour release. The results indicate an underestimation of the odour emission rate of a livestock building during summer compared with winter when using an annual mean value. For the all-in/all-out system, this effect is superposed by an overestimation at the beginning of the fattening period and an underestimation at the end. Using emission models which take into account the growth function and/or the indoor climate, a more realistic description of the odour emission characteristics can be achieved. This will help to increase the goodness of the assessment of environmental odour by dispersion models.

Odour emission characteristics of 22 recreational rivers in Nanjing

The odour emission characteristics of 22 recreational rivers in Nanjing were investigated and analysed. Eight odorous compounds (ammonia (NH₃), hydrogen sulphide (H₂S), sulphur dioxide (SO₂), carbon disulphide (CS₂), nitrobenzene (C₆H₅NO₂), aniline (C₆H₅NH₂), dimethylamine (C₂H₇N), and formaldehyde (HCHO)) were measured in odour emission samples collected using a custom-made emission flux hood chamber. The results showed that all odorants were detected in all monitoring rivers. NH₃ was the main odorant, with emission rates ranging from 4.86 to 15.13 μg/min m(2). The total odour emission rate of the Nan River, at 1 427.07 OU/s, was the highest of the all investigated rivers. H₂S, NH₃ and nitrobenzene were three key odour emission contributors according to their contributions to the total odour emission. A correlation analysis of the pollutants showed there was a significant positive correlation between the emission rate of NH₃ and the concentration of ammonia nitrogen (NH₄ (+)-N) and total nitrogen (TN). The H₂S and SO₂ emission rates had a significant positive correlation with sulphides (S(2-)) and available sulphur (AS) in the water and sediment. The content of TN, NH₄(+)-N, S(2-) and AS in the water and sediment affected the concentration of H₂S, SO₂ and NH₃ in the emission gases. NH₄(+)-N, S(2-) and AS are suggested as the key odour control indexes for reducing odours emitted from these recreational rivers. The study provides useful information for effective pollution control, especially for odour emission control for the recreational rivers of the city. It also provides a demonstrate example to show how to monitor and assess a contaminated river when odour emission and its control need to be focused on.

Odour emission scenarios for fattening pigs as input for dispersion models: A step from an annual mean value to time series

For the assessment of odour annoyance by dispersion models, the odour emission rate of the source has to be known. In general, an annual mean value is used, although the live mass of the animals increases dramatically during the fattening period and odour emission from the building is known to depend strongly on indoor air temperature and ventilation rate. This annual mean value of the odour emission rate was compared with various emission scenarios for a continuous flow production system with a constant live mass of 75kg and an all-in/all-out system. For the last one an inverse transfer sampling method was used to avoid an interaction between the growth of the animals and the annual variation of the outdoor temperature. The variation of the emission factor was taken into account twofold, first by a schematized diurnal emission pattern for the various seasons and second by a steady state simulation model that employs a sensible heat balance to calculate indoor temperature and ventilation rate which both influence the odour release. The results indicate an underestimation of the odour emission rate of a livestock building during summer compared with winter when using an annual mean value. For the all-in/all-out system, this effect is superposed by an overestimation at the beginning of the fattening period and an underestimation at the end. Using the emission model which takes into account a time series of the odour emission rate, a more realistic description of the odour emission characteristics can be achieved compared with an annual mean value.

Continuous odour measurement from fattening pig units

A study in experimental slatted-system fattening pig units was conducted with the aim of estimating the odour emission factor (in ou s.pig−1), which can subsequently be used in dispersion models to assess the odour annoyance zone. Dynamic olfactometry measurements carried out at different development stages of pigs showed a logical trend of the mean assessed odour emission factor with the pig mass. However, the variation within the same mass class was much larger than variation between classes. Possible causes of such variation were identified as the evolution of ventilation rate during the day and the circadian rhythm of pig. To be able to monitor continuously the daily variation of the odour, an electronic nose was used with suitable regression model calibrated against olfactometric measurements. After appropriate validation check, the electronic nose proved to be convenient, as a complementary tool to dynamic olfactometry, to record the daily variation of the odour emission factor in the pig barn. It was demonstrated that, in the controlled conditions of the experimental pens, the daily variation of the odour emission rate could be mainly attributed to the sole influence of the circadian rhythm of pig. As a consequence, determining a representative odour emission factor in a real case cannot be based on a snapshot odour sampling.

The performance of numerical odour assessment for the prediction of odour complaints from wastewater treatment works

AbstractNumerical odour standards are often used in conjunction with dispersion modelling to assess the acceptability of the odour environment around wastewater treatment works (WWTWs). However, the odour standards applied are based on very limited research, and there is very little information available regarding how well these standards work in practice. This paper describes the results of a study examining the relationship between odour modelling results and reported complaints around 15 WWTWs in the United Kingdom. Predicted odour concentrations around each of the works were calculated using industry standard odour emission rates. Records of reported odour complaints were obtained from the relevant local authority environmental health department. The study found that odour modelling results did not correlate well with the location of the reported complaints and that in most cases, odour modelling underestimated the area from which complaints would be received.

Odor Sampling: Techniques and Strategies for the Estimation of Odor Emission Rates from Different Source Types

Sampling is one of the main issues pertaining to odor characterization and measurement. The aim of sampling is to obtain representative information on the typical characteristics of an odor source by means of the collection of a suitable volume fraction of the effluent. The most important information about an emission source for odor impact assessment is the so-called Odor Emission Rate (OER), which represents the quantity of odor emitted per unit of time, and is expressed in odor units per second (ou·s−1). This paper reviews the different odor sampling strategies adopted depending on source type. The review includes an overview of odor sampling regulations and a detailed discussion of the equipment to be used as well as the mathematical considerations to be applied to obtain the OER in relation to the sampled source typology.

Odour, dust and non-methane volatile organic-compound emissions from tunnel-ventilated layer-chicken sheds: a case study of two farms

An observational study was undertaken to measure odour and dust (PM10 and PM2.5) emission rates and identify non-methane volatile organic compounds (NMVOCs) and odorants in the exhaust air from two tunnel-ventilated layer-chicken sheds that were configured with multi-tiered cages and manure belts. The study sites were located in south-eastern Queensland and the West Gippsland region of Victoria, Australia. Samples were collected in summer and winter on sequential days across the manure-belt cleaning cycle. Odour emissions ranged from 58 to 512 ou/s per 1000 birds (0.03–0.27 ou/s.kg) and dust emission rates ranged 0.014–0.184 mg/s per 1000 birds for PM10 and 0.001–0.190 mg/s per 1000 birds for PM2.5. Twenty NMVOCs were identified, including three that were also identified as odorants using thermal desorption–gas chromatography–mass spectrometry/olfactometry analysis. Odour emission rates were observed to vary with the amount of manure accumulation on the manure belts, being lowest 2–4 days after removing manure. Odour emission rates were also observed to vary with diurnal and seasonal changes in ventilation rate. Dust emissions were observed to increase with ventilation rate but not with manure accumulation. Some NMVOCs were identified at both farms and in different seasons whereas others were observed only at one farm or in one season, indicating that odorant composition was influenced by farm-specific practices and season.

Odour emission ability (OEA) and its application in assessing odour removal efficiency

Odourous emissions from sewer networks and wastewater treatment plants (WWTPs) can significantly impact a local population. Sampling techniques such as wind tunnels and flux hood chambers are traditionally used to collect area source samples for subsequent quantification of odour emission rates using dilution olfactometry, however these methods are unsuitable for assessing liquid samples from point sources due to the large liquid volumes required. To overcome this limitation, a gas phase sample preparation method was developed for assessing the total Odour Emission Ability (OEA) from a liquid sample. The method was validated using two volatile organic sulphur compounds (VOSCs), dimethyl-trisulphide (DMTS) and bismethylthiomethane (BMTM) that are frequently detected from sewers and WWTPs and are relatively stable compared with common VOSCs like mercaptan or methyl mercaptan. The recovery rates of DMTS and BMTM were quantified by injecting a known volume of a standard liquid sample into Tedlar bags using a static injection and a dynamic injection methodology. It was confirmed that both dynamic and static injection methods at ambient condition achieved high recovery rates with no need to consider increasing evaporation by elevating the temperature. This method can also be used to assess odour removal effectiveness of liquids by comparing the OEA before and after the treatment tests. Two application examples were presented.

Ambient Odour Assessment Similarities and Differences Between Different Techniques

This paper compares the results for ambient odour concentrations measured by three different techniques, one of which is a new developed technology; Scentroid SM110. This new instrument was developed recently in Canada for assessing ambient odour concentrations. The results obtained by this instrument were compared with two other techniques presently used for assessing ambient odours: the first technique which combines source odour testing with dispersion modelling to predict off- site odour concentration and a second technique; direct ambient odour measurement which includes collection of odour samples at the sensitive receptors with olfactometry analysis. In recent years in Canada, direct ambient odour measurements are more common and are usually combined with source testing and dispersion modelling analysis. A previous study that I carried out determined a correlation between off - site odour concentrations estimated by dispersion modelling analysis which were based on the measured odour emission rates at each potential odour sources and the direct ambient measurements using odour sampling at the sensitive receptors with olfactometry analysis. Since this time however, a new instrument- the Scentroid SM110 was developed for assessing ambient odours, and as a continuation of my previous study, this paper shows the results between the measurements obtained by the new instrument compared to traditional ambient sampling and olfactometry analysis. In addition to the comparison of these two techniques, a third technique is also contrasted to this study; the Nasal Ranger technique, which in a previous study showcased some deviancies.