Emissions Of Odorous Compounds Research Articles

Greenhouse Gas Emissions From Biofilters for Composting Exhaust Ammonia Removal.

Emissions of odorous compounds, such as ammonia (NH3), from composting have negative agronomic and environmental impacts. A biofilter is widely used for NH3 removal, with one of its potential detrimental by-products being nitrous oxide (N2O), which is a higher warming potential greenhouse gas (GHG). The aim of the study was to evaluate the effect of empty bed retention time (EBRT) on GHG emissions from biofilters for removing NH3 from composting. Composting experimental trials lasted 6 weeks, and composting materials were mixtures of dead pigs and manure. Three groups of biofilters with 1.2 m-height, 0.3 m-inner diameter, and 1.0 m media depth were conducted with EBRT of 30, 60, and 100s, respectively. Each treatment was performed in triplicate, and the gas was monitored using the dynamic emission vessel method. The Spearman’s correlation analysis showed a significantly positive correlation between inlet concentrations (ICs) of NH3 and increased N2O concentrations: ρ = 0.707, 0.762, and 0.607 with p ≤ 0.0001 for biofilters with EBRT of 30, 60, and 100s, respectively. The fraction of NH3-N denitrified into N2O-N in biofilters with EBRT of 60 and 100s was higher than that with EBRT of 30s. The total global warming potential (GWP) increased by 126%, 162%, and 144% for biofilters with EBRT of 30, 60, and 100s, respectively. These results indicated that biofilters with longer EBRT will lead to higher GWP production. Future research on odorous mitigation for composting with biofilters should focus more on greenhouse gas emissions.

Intensive Animal Farming Operations – a Preliminary Analysis of a Number of Farm Animals, Ammonia Emission Values Variability and Methods of Reducing Odor Emissions and Assessing Health Impact Taking into Account Possible Solutions in Poland and Ukraine

The article seeks to review the standards (emission and immission) and legal solutions relating to odour-active compounds, as well asanalyse the variability in the number of farmed animals and the emission of ammonia in Poland and Ukraine. Furthermore, the article characterizesodour emission factors, methods of health risk assessment, ways of limiting emission of odorous compounds from animal farming facilities. The analysis indicated the necessity of applying good practices available in reference documents – including those drawn up by environmental agencies – and scientific works, as such practices may significantly contribute to minimising the impact of animal farming facilities on people and the environment. The introduction of, inter alia, immission standards (reference values) expressed in ouE/m3 in the legal regimes of the EU and Ukraine would also render it possible to carry out an assessment of odours treated as a mixture present in ambient air and optimise the assessment of odour nuisance and thus the discomfort directly affecting the well-being and health of inhabitants of areas in the vicinity of farming facilities.

Assessing transfer distances and separation areas of odorous compounds from probability analysis with numerical dispersion modeling

Odor pollution caused by volatile compounds from waste-treatment facilities is a typical nuisance, and assessing its potential impacts is crucial. Challenges in odor-dispersion simulation and impact assessment are attributed to the occasional and fluctuant emissions of odorous compounds and varying meteorological conditions for dispersion. This study established an approach to assessing the transfer distances and determining the separation areas of odor pollution by combining probability analysis and numerical dispersion simulation. With a waste transfer station as a case, we analyzed odorous compounds from 96 samples and performed 2190 simulation rounds with different meteorological parameters throughout an entire year by using a specialized model (ModOdor). Ethanol, dimethyl disulfide, and dimethyl sulfide were identified as typical odorous compounds in terms of source intensity and detection frequency. The concentration distribution, probability of transfer distances in terms of month and year, and separation area determination from cumulative probability were investigated. Under most studied conditions, the compound concentrations rapidly decreased after being released. From the year-round perspective, an ethanol concentration exceeding 1 μg/m3 was in approximately 80% probability limited in the area with a radius of 200 m. With a cutoff of 95% probability, the closest transfer distances towards all orientations can circle the odor separation area. The compound concentrations in the separation area had a probability higher than 5% throughout the year to exceed the assigned reference concentrations. The approach and demonstration can solve the mutability problem of odor pollution from a probability perspective and thus potentially improve odor pollution control in waste management.

Prediction of odor complaints at a large composite reservoir in a highly urbanized area: A machine learning approach.

Odorous compound emissions and odor complaints from the public are rising concerns for agricultural, industrial, and water resource recovery facilities (WRRFs) near urban areas. Many facilities are deploying sensors that measure malodorous compounds and other factors related to odor creation and dispersion. Focusing on the Metropolitan Water Reclamation District of Greater Chicago's (MWRDGCs) Thornton Composite Reservoir (7.9 billion gallon capacity), we used meteorological, operational, and H2S sensor data to train a 3-day advance-warning predictor of local odor complaints, so as to implement targeted odor prevention measures. Using a machine learning approach, we bypassed difficulties in modeling both physical dispersion and human perception of odors. Utilizing random forest algorithms with varied settings and input attributes, we find that a small network of H2S sensors, meteorological data, and operational data are able to predict odor complaints three days in advance with greater than 60% accuracy and less than 25% false-positive rates, exceeding MWRDGC's standards required for full-scale deployment. PRACTITIONER POINTS: A random forest algorithm trained on H2 S, weather, and operations data successfully predicted odor complaints surrounding a large composite reservoir. Thirty-two data attribute combinations were tested. It was found that H2 S sensor data alone are insufficient for predicting odor complaints. The best predictor was a Random Forest Classifier trained on weather, operational, and H2 S readings from the reservoir corner locations. This study demonstrates odor complaint prediction capability utilizing a limited set of data sources and open-source machine learning techniques. Given a small network of H2 S sensors and organized data management, WRRFs and similar facilities can conduct advance-warning odor complaint prediction.

A Comparative Analysis of Methods for Determining Odour-Related Separation Distances around a Dairy Farm in Beijing, China

Concentrated animal feeding operations (CAFOs) such as dairy farms are a source of odorous compound emissions. In this study, by identifying relevant odour sources within a 300-head dairy farm and quantifying their emissions, we determined the separation distances to avoid odour annoyance around the dairy farm with two empirical models (Austrian and German Verein Deutscher Ingenieure (VDI) model) and a dispersion model (AERMOD). Besides, this study ponders on the selection of an appropriate meteorological station that best represents the area surrounding the farm. Results show that the maximum separation distances of an exceedance probability of P = 15% determined by the two empirical and the dispersion models are 524 m, 440 m and 655 m, while the minimum values are 202 m, 135 m, and 149 m, respectively. The NE–SW stretching separation distances match well with the wind rose. The mean ratios of separation distances determined by the two empirical models to that of the dispersion model are 1.23 and 0.95. Moreover, statistics of the separation distances indicate good accordance between the empirical models and the dispersion model.

Sensitivity analysis of the WATER9 model: emissions of odorous compounds from passive liquid surfaces present in wastewater treatment plants

Empirical mathematical models have been frequently used to estimate emissions and to act in the prevention of possible impacts from odorous compounds. Based on the regulatory WATER9 model, the present study had the aim to evaluate the deviations originating from the simplification of using the effective diameter (in contrast to the conceptually appropriate use of the linear physical fetch) as fetch parameter in the calculation of the global mass transfer coefficient at passive liquid surfaces at wastewater treatment plants (WWTPs). The present analysis incorporated the influence of different values of wind velocity, molecular diffusivity and Henry's Law constant. The analyses for the calculation of the mass transfer coefficients were developed for 1,000 wind speeds, chosen using the Monte Carlo method, three WWTPs and three compounds of environmental relevance, spanning different behaviour regarding their volatilisation. The wind speed had a direct influence on the deviations for all types of compounds analysed. However, this parameter was found to be more representative for the compounds whose volatilisation is limited by conditions in the liquid phase. Furthermore, the deviations for the calculation of the mass transfer coefficient arising from the use of the effective diameter as fetch parameter were significantly larger for liquid phase-dominated compounds, compared to gas phase-dominated compounds. Comparison against available experimental data confirm that the use of the effective diameter as the fetch parameter makes the model predictions further depart from the experimental values. The present analysis shows that, for a varied range of wind speed and WWTP configurations, the use of the actual physical fetch shall be preferred over the use of the effective diameter in emission models for WWTPs, so as to avoid the introduction of potentially large systematic deviations.

Removal of odorous compounds emitted from a food-waste composting facility in Korea using a pilot-scale scrubber

ABSTRACTMonitoring and control of odorous compound emissions have been enforced by the Korean government since 2005. One of the point sources for these emissions was from food waste composting facilities. In this study, a pilot-scale scrubber installed in a composting facility was evaluated for its performance in the removal of malodorous compounds. The exhaust stream contained ammonia and methylamine as the major odorants detected by the threshold odor test and various instrumental techniques (GC-FID, FPD, MS and HPLC/UV). For the scrubber operation, the column was randomly packed with polypropylene Hi-Rex 200, while aqueous sulfuric acid was selected as the scrubbing solution. To achieve 95% removal, the scrubber must be operated by using H2SO4 solution with pH at < 6.5, liquid to gas ratio > 4.5, gas loading rate < 1750 m3/m3-hr and contact time < 0.94 s. The scrubber performance was further evaluated by determining the mass transfer coefficients and then monitoring for 355 days of operation. The pilot-scale scrubber maintained > 95% ammonia and methylamine removal efficiencies despite the fluctuations in the inlet (from composting facility exhaust stream) concentration. The optimum operating conditions and scrubber performance indicators determined in this study provides a basis for the design of a plant-scale scrubber for treatment of composting facility gas emissions.

Formaldehyde and volatile organic compound (VOC) emissions from particleboard: Identification of odorous compounds and effects of heat treatment

Furniture and building/furnishing materials are major sources of indoor volatile organic compounds (VOCs), and the VOC emission characteristics of these materials are essential for understanding indoor air pollution dynamics. Herein, we investigated the emission characteristics of formaldehyde (HCHO) and other VOCs from particleboard in sealed or ventilated environmental chambers at different temperatures (23, 35 or 50 °C), with a focus on the emission of odorous compounds. The emissions of HCHO and total VOCs (TVOC) from the particleboard increased significantly with temperature, and the emitted VOC mixtures had complex chemical compositions. In addition to HCHO, 44 compounds were identified, including alkanes, (chlorinated) aromatic hydrocarbons, carbonyl compounds (i.e., aldehydes and ketones), alcohols, and esters, etc. At room temperature (23 °C), n-hexane was the most abundant compound except HCHO; but at higher temperatures, concentrations of hexanal and pentanal significantly increased. Moreover, due to their low odor thresholds, aldehydes, particularly hexanal and pentanal, were identified as the major odorous compounds emitted from the particleboard. Enhanced ventilation could effectively decrease VOC concentrations in the environmental chamber at room temperature, but less effectively at higher temperatures. After heat treatment at 50 or 60 °C, the emissions of HCHO and TVOC at room temperature decreased significantly. More importantly, because the emissions of hexanal and pentanal were highly sensitive to temperature, their emission strengths were effectively reduced after heat treatment, resulting in significantly lowered odor emissions from the particleboard at room temperature. These results are helpful for the control of indoor odor problems arising from furniture materials.

Odor and Odorous Compound Emissions from Manure of Swine Fed Standard and Dried Distillers Grains with Soluble Supplemented Diets.

This study was conducted to determine the impact of diets containing dried distillers grains with solubles (DDGS) on emissions of odor and odorous compounds from swine manure storage. Twenty-four pigs were fed either a corn-soybean meal (CSBM) diet or a diet containing 35% DDGS over a 42-d feeding trial. Their waste was collected and transferred to individual manure storage containers. Manure from pigs fed diets containing DDGS had significantly lower odorant emissions expressed in animal units for hydrogen sulfide (HS) and ammonia (NH) ( < 0.05) compared with pigs fed the CSBM diet, but emissions of volatile fatty acids and phenolic compounds were significantly higher ( < 0.05) for manures from animals fed the DDGS diet. There was no significant difference for indole compound emissions due to the dietary treatment applied. Emissions of volatile organic compounds (VOCs) from manure accounted for less than 0.1% of carbon consumed for either diet. There were no significant differences in odor emissions for either diet as quantified with human panels or measured as the sum total of the odor activity value. Manure odors from pigs fed the CSBM diet were dominated by HS, whereas animals fed the diet containing DDGS were dominated by VOCs.

The effect of slurry treatment including ozonation on odorant reduction measured by in-situ PTR-MS

Abstract The emission of odorous compounds from intensive pig production facilities is a nuisance for neighbors. Slurry ozonation for odor abatement has previously been demonstrated in laboratory scale. In this study, the effect of slurry ozonation (combined with solid–liquid pre-separation and acidification) on emissions of odorous compounds was tested in an experimental full-scale growing pig facility using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) for online analysis of odorants. The measurements were performed to gain a better understanding of the effects of ozone treatment on emissions odorous compounds and to identify potential options for optimization of ozone treatment. The compounds monitored included volatile sulfur compounds, amine, carboxylic acids, ketones, phenols and indoles. Measurements were performed during nearly a one-month period in summertime. The compounds with the highest concentrations observed in the ventilation exhaust duct were acetic acid, hydrogen sulfide, propanoic acid and butanoic acid. The compounds with the highest removal efficiencies were hydrogen sulfide, 3-methyl-indole, phenol and acetic acid. Based on odor threshold values, methanethiol, butanoic acid, 4-methylphenol, hydrogen sulfide and C5 carboxylic acids are estimated to contribute significantly to the odor nuisance. Emissions of odorous compounds were observed to be strongly correlated with temperature with the exception of hydrogen sulfide. Emission peaks of sulfur compounds were seen during slurry handling activities. Discharging of the slurry pit led to reduced hydrogen sulfide emissions, but emissions of most other odorants were not affected. The results indicate that emissions of odorants other than hydrogen sulfide mainly originate from sources other than the treated slurry, which limits the potential for further optimization. The PTR-MS measurements are demonstrated to provide a quantitative, accurate and detailed evaluation of ozone treatment for emission reduction.

Odorant Emissions from Intensive Pig Production Measured by Online Proton-Transfer-Reaction Mass Spectrometry

Emission of odorous compounds from intensive livestock production is a cause of nuisance in populated rural areas. Knowledge on the chemical composition of odor and temporal variations in emissions are needed in order to identify factors of importance for emission rates and select proper abatement technologies. In this work, a method based on proton-transfer-reaction mass spectrometry (PTR-MS) has been developed and tested for continuous measurements of odorant emissions from intensive pig production facilities. The method is assessed to cover all presently known important odorants from this type of animal production with adequate sensitivity and a time resolution of less than one minute. The sensitivity toward hydrogen sulfide is demonstrated to exhibit a pronounced humidity dependency, which can be included in the calibration procedure in order to achieve quantitative results for this compound. Application of the method at an experimental pig facility demonstrated strong temporal variations in emissions, including diurnal variation. Based on these first results, air exchange and animal activity are suggested to be of importance for emission rates of odorants. Highest emissions are seen for hydrogen sulfide and acetic acid, whereas key odorants are evaluated from tabulated odor threshold values to be hydrogen sulfide, methanethiol, 4-methylphenol, and butanoic acid.

도시 생활폐기물 매립지에서 발생되는 악취물질의 조성에 대한 연구

In this study, sampling and analysis was carried out for 13 compounds, in order to investigate the odorous compound emissions from landfill stacks and surrounding ambient air. These results revealed that concentration of hydrogen sulfide was in the ambient air. Also, concentrations of hydrogen sulfide () were the highest value in odorous sulfur compounds from landfill stacks. In case of VOC, toluene was obtained the highest out of volatile organic compounds. It was found that the concentrations of hydrogen sulfide near the landfill was higher than that inside city such as Seoul although it was located in a rural area. The result was due to the effect of hydrogen sulfide emitted from landfill stacks.

Reduction of Ammonia and Hydrogen Sulfide Emission from Swine Manure Using Aqueous Foams Amended with Microorganisms and Chemical Additives

AbstractAqueous foam, in combination with microorganisms and chemical additives, was tested for the reduction of the emissions of odorous compounds from swine manure. Ammonia and hydrogen sulfide were selected as test compounds. Aqueous foam decreased the ammonia and hydrogen sulfide emissions by about 33.2 and 66.2%, respectively, after application for 1,800 min. With the application of aqueous foam, amended with 1% of monocalcium phosphate or Yucca extracts, about 81.4 and 51.6%, respectively, of the ammonia emissions were suppressed over the same time period. However, the chemical additives were found to be ineffective in the suppression of hydrogen sulfide. Finally, the aqueous foam, containing microorganisms and the two chemical additives, attained about 88.3 and 70% ammonia and hydrogen sulfide emissions suppression, respectively. The data show that the aqueous foam was effective in the control ammonia and hydrogen sulfide emissions, and the suppression capacity can be markedly enhanced by the addition of appropriate microorganisms and chemical additives.

Mitigation of Ammonia and Hydrogen Sulfide Emissions by Stable Aqueous Foam-Microbial Media

Stable aqueous foam-microbial media consisting of protein-based foams and odor-degrading bacteria were developed to control the emissions of odorous compounds. The optimum foam formulation was determined based on foam characteristics including 50% drainage time, foam lifetime, and foam expansion ratio. When only the aqueous foam was applied onto the surface of a test odor source (i.e., swine manure), ammonia emission was completely suppressed for about 177, 225, 265, 297, and 471 min when the height of foam barrier was 2.5, 5, 10, 15, and 30 cm, respectively. According to the increasing foam height, ammonia emission rates after breakthrough points decreased to 0.16, 0.13, 0.09, 0.07, and 0.02 mg/m3/min, and thus volatilized ammonia concentrations decreased significantly after 600 min. Hydrogen sulfide was similarly suppressed. Ammonia emission was better controlled by incorporating odor-degrading bacteria into the aqueous foam. The odor suppression capacity of the 5-cm foam barrier with microbes was more than eight times greater than that of the barrier only and was similar to that of 30-cm foam barrier without microbes after 1440 min. A significant amount of dinitrogen gas was evolved by the foam-microbial media, indicating a successful biological transformation of ammonia.

Comparison and development of dynamic flux chambers to determine odorous compound emission rates from area sources

Two dynamic flux chambers for direct measurement of odorous compound emissions from quiescent liquid surfaces were investigated under simulated conditions in the laboratory. Initially, a flux chamber built according to the model recommended by French standard NF X 43-104 was studied. This chamber was used in two different ways. The first led to a lack of precision concerning emissions rates from the sampled liquid surface, whereas the second led to an overestimation of the measurements. The second part of the study was devoted to an improved dynamic flux chamber, built according to the feedback from the results obtained using the normalised sampling system. Laboratory tests showed good accuracy and precision. This work underlines the importance of the aerodynamic performances of a dynamic sampling system.

Effect of duckweed cover on greenhouse gas emissions and odour release from waste stabilisation ponds

Treatment of wastewater in stabilisation pond systems prevents the negative environmental impact of uncontrolled disposal of sewage. However, even a natural treatment system may generate secondary negative environmental impacts in terms of energy consumption, emission of greenhouse gases and emission of odorous compounds. Whereas natural systems have an advantage over electro-mechanical systems in that they use less hardware and less energy, it is not yet known whether secondary environmental effects in the form of greenhouse gas emissions are lower for these systems. This research intends to be a first step in the direction of answering this question by assessing gas emissions from two types of natural systems, namely algae-based and duckweed-based stabilisation ponds. The H2S volatilisation from laboratory scale pond-reactors has been determined by drawing the air above the water surface continuously through a solution of 1 M NaOH for absorption of sulphide. The amount of H2S that volatilised from the algae pond-reactor, and was trapped in the NaOH trap, was found to be 2.5-86 mg/m2/day. The H2S volatilisation from the duckweed pond-reactor was found to be negligible, even though the sulphide concentration was 9.7 mg/l S(2-). The duckweed cover was a physical barrier for volatilisation, since bubbles were trapped in the cover. In addition the duckweed layer was found to be afavourable environment for both aerobic sulphide oxidisers (Beggiatoa gigantae) as well as for photosynthetic purple sulphur bacteria belonging to the genus Chromatium. These may also have contributed to the prevention of H2S volatilisation. Results on methane emissions were not conclusive so far, but the same mechanisms that prevent H2S volatilisation may also prevent methane volatilisation. Therefore it was concluded that duckweed covers on stabilisation ponds may reduce the emission of both odorous and greenhouse gases.

Emission of H2S and mass balance of sulfur in anaerobic ponds

Anaerobic ponds are highly efficient at removing BOD from wastewater with a reduced land area requirement. However, their use is often limited because of the problem of odor release, primarily due to the emission of hydrogen sulfide (H2S). The experiments were conducted on full scale anaerobic ponds used for the primary treatment of urban wastewater under Mediterranean climatic conditions (south of France). A model was developed to estimate the emission of H2S from water characteristics (temperature, pH and sulfides concentration). The emission rate from anaerobic ponds varied between 20 and 576 mg-S/m2.d, leading to concentrations of H2S in the surrounding atmosphere between 0.2 and 5.2 ppm. These concentrations risked creating odor nuisances for nearby inhabitants. The whole of the results and the analysis of sulfur species in sludge permitted the production of a complete mass balance for sulfur. Methods of reducing the emission of odorous compounds were tested on a large scale. The recirculation of secondary effluent and the use of impermeable or permeable covers appeared to be the most interesting solutions.

Relationship between Organic Matter Decomposition and Odorous Compounds' Emission during Thermophilic Composting

We investigated the effect of inoculant on the emission of odorous compounds during isothermal thermophilic composting processes at 60°C. Of these compounds, ammonia and odorous sulfur compounds, hydrogen sulfide (H 2 S), methylmercaptane (MMC), dimethylsulfide (DMS), and dimethyldisulfide (DMDS) were measured. We used three different inoculants, and found that composting with two of them, where vigorous organic matter decomposition occurred, generated a very high concentration of NH 3 , as high as 4000 ppm, and also generated high concentrations of sulfur compounds, especially of MMC and DMDS. In contrast, very few odorous compounds were emitted during composting with the third inoculant; however, there was an extremely small degree of organic matter decomposition in this composting. These results indicate that it is not sufficient to merely compare odor emission when assessing the best operational conditions for composting with a small amount of odor emission. In other words, in assessing composting operations with regards to the effective reduction of odor emissions, it is important to simultaneously quantify the degree of organic matter decomposition that occurs.

Ocular, airway, and dermal symptoms related to building dampness and odors in dwellings.

The authors examined the relationship between symptoms of Sick Building Syndrome and reports of building dampness and odors. Two hundred thirty-one multifamily buildings built prior to 1961 in Stockholm, Sweden, contained a total of 4,815 dwellings. The authors selected these buildings for study by stratified random sampling. Occupants answered a postal questionnaire that assessed weekly symptoms, personal factors, population density in each apartment, water leakage in the preceding 5 yr, different types of odors, and signs of high indoor air humidity. The response rate was 77%. Independent information on building characteristics was gathered from the building owners and the central building register in Stockholm. Multiple logistic-regression analysis was applied and odds ratios were calculated, with adjustments for age, gender, current smoking, hay fever, population density, type of ventilation, and ownership of the building. In total, 22% reported at least 1 sign of dampness, and 32% reported odor in the dwelling. Condensation on windows, high air humidity in the bathroom, moldy odor, and water leakage were reported from 6.8%, 8.8%, 5.7%, and 13% of the dwellings, respectively. A combination of odor and signs of high humidity was related to an increased occurrence of all symptoms (odds ratios = 2.2-3.6). Similar findings were observed for a combination of odors and a history of water leakage in the past 5 yr (odds ratios = 1.2-4.4). Symptoms increased with the number of signs of dampness. The study indicated that dampness in dwellings, with emissions of odorous compounds, are associated with an increase in symptoms consistent with Sick Building Syndrome.

Penalization of the environment due to stench: A study of the perception of odorous air pollution by the population

In this paper a mathematical model is developed, with the aid of which the perception of odorous pollution by the population, living in the vicinity of chemical industry, can be described quantitatively. As odour is a non-defined composite name for the combined effect of a large number of odorous compounds, a new operational notion is introduced, i.e. penalization of the environment due to stench, being defined as the proportion of the population capable of perceiving odorous pollution. The mathematical model is based on the assumption: “Over a chemical-industrial terrain, the large number of emissions of odorous compounds, even those which individually may seem unimportant, determines the quality of the air for the population”. The model is applied to the situation in 5 areas in The Netherlands. Results of calculation are compared with results of public polls and with the complaint pattern as registered by the Central Complaint Office of the Rijnmond Authority. The agreement between calculation and observation is in the statistical sense highly significant. This permits the drawing of some policy-relevant conclusions, as to a directed abatement of odorous pollution, improved regional planning, and a criterion, which may lead to a standard for odorous pollution.