Odor Control Technologies Research Articles

Основные подходы к снижению запахового загрязнения окружающей среды предприятиями животноводства (обзор)

Modern industrial livestock production is accompanied by emissions into the environment of a wide range of odorforming substances (OFS), which negatively affect the health and quality of life of the population. The problem of protecting atmospheric air from odour pollution (OP) is of high relevance and practical significance. The review critically appraises scientific publications on the control of OP from livestock and poultry farms. Methods of control include the processing of manure with deodorizing materials (reagents, sorbents, enzymes, etc.); inoculation with microorganism strains; adjustment of animal diets; air purification from pollutants; optimization of dispersion; isolation of ОР sources; and odor masking. Agriculture’s focus on adopting green technologies has increased interest in searching environmentally friendly methods of odor control. These are the use of plant extracts, natural sorbents, effective microorganism strains, biofilters, bioscrubbers, biogas plants, planting of protective forest belts that promote the absorption of dust and dispersion of OFS. Each method of OP control has both advantages and disadvantages. Modern “green” methods effectively eliminate odors in large farms, but require high investment and operating costs, which limits their implementation in practice, and relatively low-cost methods (the use of reagents, sorbents, flavoring agents, feed additives) are usually not effective enough. An acceptable result can be obtained by combining various methods of limiting the OFS emission. Control strategies should be selected based on the source of the odor, the effectiveness of the technology on the particular farm, and the cost/benefit ratio of the odor control technology into practice.

Odor control technologies for municipal solid waste mechanical biological treatment plant: a review

Odor control technologies for municipal solid waste mechanical biological treatment plant: a review

Effectiveness of Malodor-Reducing Ostomy Pouch Additives: An Assessment of Odor Intensity, Hedonic Tone, and Odor Character.

Background Ostomy pouch odor can have a negative impact on the quality of life of people living with a stoma. This study assessed the effectiveness of malodor-reducing ostomy pouch additives under simulated conditions. Methodology The following six commercially available products with different odor control technologies plus a control were assessed: soyethyl morpholinium ethosulphate, zinc ricinoleate (ZnR), ZnR with orange terpenes (ZnR-Orange), a proprietary copper-based deodorant, a proprietary ion mix deodorant, and a terpene blend (TB). Each was added to an ostomy pouch with skatole (a substitute for human fecal odor). Professional olfactometrists rated odors according to intensity, hedonic tone (pleasantness), and character. Results The TB and ZnR-Orange had very weak (<1.0) malodor intensity, with mean (standard deviation [SD]) ratings of 0.6 (1.1) and 0.9 (0.9), respectively. All other products (2.7-3.0) and control (3.7) were statistically higher (stronger intensity) compared with the TB(p < 0.001). The mean (SD) hedonic tone for the TB was 0.8 (1.7) (considered slightly pleasant); all other products (-0.8 to 0.1) and control (-0.9) were statistically lower (p < 0.001). Odor character profiles were broadly comparable, but products with scent additives (TB and ZnR-Orange) were predominantly associated with fragrances. Conclusions This information may help nurses and other healthcare providers when educating ostomates about their options. Other factors such as application mode and recommended dosage may also influence the choice of product. Future research on real-world populations (i.e., ostomates), as well as assessment of lubrication properties, is warranted.

Effect of odor treatment systems on bioaerosol microbial concentration and diversity from wastewater treatment plants

Biofiltration, activated carbon and chemical scrubbing are technologies used for odor control in wastewater treatment plants. These systems may also influence the airborne microbial load in treated air. The study objectives were to 1) evaluate the capacity of three odor control system technologies to reduce the airborne concentration of total bacteria, Legionella, L. pneumophila, non-tuberculous mycobacteria (NTM) and Cladosporium in winter and summer seasons and 2) to describe the microbial ecology of the biofiltration system and evaluate its impact on treated air microbial diversity. A reduction of the total bacterial concentration up to 25 times was observed after odor treatment. Quantification by qPCR revealed the presence of Legionella spp. in all air samples ranging between 26 and 1140 GC/m3, while L. pneumophila was not detected except for three samples below the limit of quantification. A significant increase of up to 25-fold of Legionella spp. was noticed at the outlet of two of the three treatment systems. NTM were ubiquitously detected before air treatment (up to 2500 GC/m3) and were significantly reduced by all 3 systems (up to 13-fold). Cladosporium was measured at low concentrations for each system (< 190 GC/m3), with 68 % of the air samples below the limit of detection. Biodiversity results revealed that biofiltration system is an active process that adapts to air pollutants over time. Legionella spp. were detected in significant abundance in the air once treated in winter (up to 27 %). Nevertheless, the abundance of protozoan hosts is low and does not explain the multiplication of Legionella spp. The season remains the most influential factor shaping biodiversity. In summer only, air biofiltration caused a significant enrichment of the biodiversity. Although odor control technologies are not designed for bacterial mitigation, findings from this study suggest their potential to reduce the abundance of some genera harboring pathogenic species.

Model-based design and operation of biotrickling filters for foul air H2S removal at wastewater networks

Biotrickling filters (BTFs) are odour control technologies that utilise the action of sulfur oxidising bacteria to treat foul air contaminated with H2S. BTFs are complex systems where an immobilised biofilm is allowed to grow on a supportive solid media, while the foul air flows counter-currently with a stream of trickling liquid. In this work, a mechanistic model is developed, based on first principles where applicable, that describes the interphase mass transfer and biological oxidation kinetics. The model also focuses on the spatial discretisation of a BTF bed and describes the competition between sulfur oxidising bacteria (SOB) and aerobic heterotrophs growing within different niches of the bed. The model successfully produced concentration profiles over time and space of all relevant chemical and biological species within the bed. The model was then used to theoretically investigate the effect of design and operating parameters on the bed performance. It was found that the optimum liquid rate could vary significantly based on other factors such as bed size and inlet H2S concentrations but a typical value lies between 0.3 and 1.3 m/hr, with a larger bed and/or higher H2S loads requiring higher loading rates to achieve the same treatment levels. The model also predicted that bed shape has no significant impact on H2S removal, provided all other conditions are the same. The model successfully allowed for more detailed design of industrial BTF units in terms of both sizing and tuning of operational parameters.

Short Introduction to the Summary and Evaluation of the Odour Regulations Worldwide

When it comes to air pollution complaints, odours are often the most significant contributor. Sources of odour emissions range from natural to anthropogenic. Mitigation of odour can be challenging, multifaceted, site-specific, and is often confounded by its complexity—defined by existing (or non-existing) environmental laws, public ordinances, and socio-economic considerations. The objective of this paper is to review and summarize odour legislation in selected European countries (France, Germany, Austria, Hungary, United Kingdom, Spain, The Netherlands, Italy, Belgium), North America (USA and Canada), South America (Chile and Colombia), as well as Oceania (Australia and New Zealand) and Asia (Japan, China). Many countries have incorporated odour controls into their legislation. However, odour-related assessment criteria tend to be highly variable between countries, individual states, provinces and even counties and towns. Legislation ranges from (1) no specific mention in environmental legislation that regulates pollutants which are known to have an odour impact to (2) extensive details about odour source testing, odour dispersion modeling, ambient odour monitoring, (3) setback distances, (4) process operations, and (5) odour control technologies and procedures. Agricultural operations are one specific source of odour emissions in rural and suburban areas and a model example of such complexities. Management of agricultural odour emissions is important because of the dense consolidation of animal feeding operations and the advance of housing development into rural areas. Overall, there is a need for continued survey, review, development, and adjustment of odour legislation that considers sustainable development, environmental stewardship, and socio-economic realities, all of which are amenable to a just, site-specific, and sector-specific application.

Summary and Overview of the Odour Regulations Worldwide

When it comes to air pollution complaints, odours are often the most significant contributor. Sources of odour emissions range from natural to anthropogenic. Mitigation of odour can be challenging, multifaceted, site-specific, and is often confounded by its complexity—defined by existing (or non-existing) environmental laws, public ordinances, and socio-economic considerations. The objective of this paper is to review and summarise odour legislation in selected European countries (France, Germany, Austria, Hungary, the UK, Spain, the Netherlands, Italy, Belgium), North America (the USA and Canada), and South America (Chile and Colombia), as well as Oceania (Australia and New Zealand) and Asia (Japan, China). Many countries have incorporated odour controls into their legislation. However, odour-related assessment criteria tend to be highly variable between countries, individual states, provinces, and even counties and towns. Legislation ranges from (1) no specific mention in environmental legislation that regulates pollutants which are known to have an odour impact to (2) extensive details about odour source testing, odour dispersion modelling, ambient odour monitoring, (3) setback distances, (4) process operations, and (5) odour control technologies and procedures. Agricultural operations are one specific source of odour emissions in rural and suburban areas and a model example of such complexities. Management of agricultural odour emissions is important because of the dense consolidation of animal feeding operations and the advance of housing development into rural areas. Overall, there is a need for continued survey, review, development, and adjustment of odour legislation that considers sustainable development, environmental stewardship, and socio-economic realities, all of which are amenable to a just, site-specific, and sector-specific application.

Odor in textiles: A review of evaluation methods, fabric characteristics, and odor control technologies

During use, textile items can develop unpleasant odors that arise from many different sources, both internal and external to the human body. Laundering is not always effective at removing odors, with odor potentially building up over time due to incomplete removal of soils and odorous compounds and/or malodors transferred during the laundering process. Textile odor can lead to consumer dissatisfaction, particularly as there are high expectations that clothing and textile products meet multiple aesthetic and functional needs. The problem of odor in textiles is complex and multi-faceted, with odorous volatile compounds, microorganisms, and precursors to odor, such as sweat, being transferred to, and retained by, fabrics. This article reviews the literature that specifically relates to odor within textiles. Methods for evaluating odor in textiles, including methods for collecting odor on textile substrates, as well as sensory and instrumental methods of odor detection, were reviewed. Literature that examined differences among fabrics that varied by fabric properties were reviewed. As well, the effectiveness of specific odor controlling finishing technologies to control malodor within textiles was also examined.

Technical and economic investigation of chemical scrubber and bio-filtration in removal of H2S and NH3 from wastewater treatment plant

A detailed techno-economic comparison of a chemical scrubber (CS) and a bio-filter (BF) was conducted over a 45-day time period at a municipal wastewater treatment plant (WWTP), Yazd city. The assessment of emissions quantity indicated that odor emissions from the Yazd WWPT mainly consist of hydrogen sulfide (H2S) and ammonia (NH3). It was also found that odor gaseous loading changes corresponding to water consumption pattern in society (R2 = 0.922) for H2S and (R2 = 0.978) for NH3. The highest level of 25 and 3 ppm for H2S and NH3, respectively were detected at specific times during the day. The BF system was continuously supplied with Yazd WWPT's off-gas treatment while the CS was only examined at the times during the day when the gas emissions are at the highest level. The removal efficiency of NH3 and H2S were found to be affected by their respective loading rate. Additionally, among the various oxidants examined in the CS, the NaOCl solution showed the best results in terms of removal efficiency and compatibility. The experiment revealed almost complete removal of NH3 while the H2S removal efficiency remained above 95% for both systems regardless of the operating conditions. This study clearly demonstrates the effectiveness of both systems in treating actual waste gases containing H2S and NH3. By comparing the gas loading rate of both systems and considering limitations of the BF system, the CS seems to be more efficient applicable odor control technology from a technical viewpoint. From the economic viewpoint, comparisons revealed that chemical usage and operating expenses were costly parts of the CS and the BF, respectively. The economic indexes of 1.58 €.m−3. h−1 and 2.57 €.m−3. h−1 were obtained for the BF and CS, respectively, reflecting cost-effectiveness of the BF system.

Indigenous butyric acid-degrading bacteria as surrogate pit latrine odour control: isolation, biodegradability performance and growth kinetics

Butyric acid is one of the volatile organic compounds that significantly contribute to malodour emission from pit latrines. The purpose of this work is to isolate and identify bacterial strains that have the capability to degrade butyric acid, determine their butyric acid degradation efficiencies and estimate their growth pattern parameters of microbiological relevance. Pure cultures of bacterial strains capable of degrading butyric acid were isolated from pit latrine faecal sludge using an enrichment technique and were identified based on 16S rRNA analysis. The bacterial strains were cultured in mineral salt medium (MSM) supplemented with 1000 mg L−1 butyric acid, as a sole carbon and energy source, at 30 ± 1 °C, pH 7 and 110 rpm under aerobic growth conditions. The modified Gompertz model was used to estimate growth pattern parameters of microbiological relevance. Bacterial strains were phylogenetically identified as Alcaligenes sp. strain SY1, Achromobacter animicus, Pseudomonas aeruginosa, Serratia marcescens, Achromobacter xylosoxidans, Bacillus cereus, Lysinibacillus fusiformis, Bacillus methylotrophicus and Bacillus subtilis. The bacterial strains in pure cultures degraded butyric acid of 1000 mg L−1 within 20–24 h. The growth kinetics of the bacterial strains in pure culture utilising butyric acid were well described by the modified Gompertz model. This work highlights the potential for use of these bacterial strains in microbial degradation of butyric acid for deodorisation of pit latrine faecal sludge. This work also contributes significantly to our understanding of bioremediation of faecal sludge odours and informs the development of appropriate odour control technologies that may improve odour emissions from pit latrines.

Current Status and Outlook of Odor Removal Technologies in Wastewater Treatment Plant

The ever increasing public complaints arising from wastewater treatment plants (WWTPs) grow since sewerage treatment has been associated with nauseous odorous on account of the anaerobic decomposition process and emission. Various physical/chemical and/or biological methods were used for abating odours worldwide. Thus, an updated comprehensive review for the WWTP odor abatement technologies is urgently required. This study reviews the new achievements of odor abatement technologies (adsorption, chemical scrubbing, biofiltration, biotrickling, bioscrubbing, activated sludge diffusion) in WWTPs and then identifies a new aspect for the future studies. Overall, hybrid technologies (physical/chemical + biotechnologies) attract increasing attention since their highly reliable removal efficiency for various odorants, however, the high costs for investment and O&M (operation & maintenance) of the adsorption part and the complexity and variability of odorants are still the major challenging for wide engineering application and technological innovation. Thus, developing the cost-effective, environmentally friendly odor control technologies, like using the alum sludge (waterworks residue) based adsorbents/media, in terms of using “waste” for waste treatment, could be a highly promising prospect.

Technological and life cycle assessment of organics processing odour control technologies

As more municipalities and communities across developed world look towards implementing organic waste management programmes or upgrading existing ones, composting facilities are emerging as a popular choice. However, odour from these facilities continues to be one of the most important concerns in terms of cost & effective mitigation. This paper provides a technological and life cycle assessment of some of the different odour control technologies and treatment methods that can be implemented in organics processing facilities. The technological assessment compared biofilters, packed tower wet scrubbers, fine mist wet scrubbers, activated carbon adsorption, thermal oxidization, oxidization chemicals and masking agents. The technologies/treatment methods were evaluated and compared based on a variety of operational, usage and cost parameters. Based on the technological assessment it was found that, biofilters and packed bed wet scrubbers are the most applicable odour control technologies for use in organics processing faculties. A life cycle assessment was then done to compare the environmental impacts of the packed-bed wet scrubber system, organic (wood-chip media) bio-filter and inorganic (synthetic media) bio-filter systems. Twelve impact categories were assessed; cumulative energy demand (CED), climate change, human toxicity, photochemical oxidant formation, metal depletion, fossil depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, terrestrial eco-toxicity, freshwater eco-toxicity and marine eco-toxicity. The results showed that for all impact categories the synthetic media biofilter had the highest environmental impact, followed by the wood chip media bio-filter system. The packed-bed system had the lowest environmental impact for all categories.

Applying odor control technologies using reliability and sustainability criteria – examples of full-scale outcomes

Applying odor control technologies using reliability and sustainability criteria – examples of full-scale outcomes

Performance Testing of Multiple Odor Control Technologies at One WWTP – What Works and What Doesn’t?

Performance Testing of Multiple Odor Control Technologies at One WWTP – What Works and What Doesn’t?

악취물질인 유기산 제거를 위한 DBD 플라즈마 촉매 복합공정의 적용

Abstract Odor control technology include absorption, adsorption, incineration and biological treatments. But, most of processes have some problems such as secondary organic acids discharge at the final odor treatment facility. In order to solve the problems for effective treatment of organic acids in odor, it is necessary to develop a new type advanced odor control technology. Some of the technology are plasma only process and plasma hybrid process as key process of the advanced technology. In this study, odor removal performance was compared DBD(Dielectric Barrier Discharge)plasma process with PCHP(plasma catalysis hybrid process) by gaseous ammonia, formaldehyde and acetic acid. Plasma only process by acetic acid obtained higher treatment efficiency above 90%, and PCHP reached its efficiency up to 96%. Acetic acid is relatively easy pollutant to control its concentration other than sulfur and nitrogen odor compounds, because it has tendency to react with water quickly. To test of the performance of DBD plasma process by applied voltage, the tests were conducted to find the dependence of experimental conditions of the applied voltage at 13 kV and 15 kV separately. With an applied voltage at 15 kV, the treatment efficiency was achieved to more higher than 13 kV from 83% to 99% on ammonia, formaldehyde and acetic acid. It seems to the odor treatment efficiency depends on the applied voltage, temperature, humidity and chemical bonding of odors.

Study on the Effect of Different Water Treatment Technology on Removing 2-MIB

To compare the removal efficiency of 2-MIB by traditional water treatment, prechlorination, O3-BAC, MIEX pre adsorption and UV/H2O2 advanced oxidation process, the pilot-test of drinking water odor control technology were studied in this paper. The results showed that the traditional water treatment process had poor effect on removing 2-MIB, with about 10% removal rate, while the O3-BAC process was the best at removing 2-MIB, whose removal rate reached over 90%. And the 2-MIB removal rate of UV/H2O2 process was about 55% and that of prechlorination process was about 20%. However, the MIEX pretreatment process had almost no effect on removing 2-MIB.

Evaluating odour control technologies using reliability and sustainability criteria – a case study for water treatment plants

Technologies for odour control have been widely reviewed and their optimal range of application and performance has been clearly established. Selection criteria, mainly driven by process economics, are usually based on the air flow volume, the inlet concentrations and the required removal efficiency. However, these criteria are shifting with social and environmental issues becoming as important as process economics. A methodology is illustrated to quantify sustainability and robustness of odour control technology in the context of odour control at wastewater treatment or water recycling plants. The most commonly used odour abatement techniques (biofiltration, biotrickling filtration, activated carbon adsorption, chemical scrubbing, activated sludge diffusion and biotrickling filtration coupled with activated carbon adsorption) are evaluated in terms of: (1) sustainability, with quantification of process economics, environmental performance and social impact using the sustainability metrics of the Institution of Chemical Engineers; (2) sensitivity towards design and operating parameters like utility prices (energy and labour), inlet odour concentration (H2S) and design safety (gas contact time); (3) robustness, quantifications of operating reliability, with recommendations to improve reliability during their lifespan of operations. The results show that the odour treatment technologies with the highest investments presented the lowest operating costs, which means that the net present value (NPV) should be used as a selection criterion rather than investment costs. Economies of scale are more important in biotechniques (biofiltration and biotrickling filtration) as, at increased airflows, their reduction in overall costs over 20 years (NPV20) is more extreme when compared to the physical/chemical technologies (chemical scrubbing and activated carbon filtration). Due to their low NPV and their low environmental impact, activated sludge diffusion and biotrickling filtration are in general the most cost-effective, and probably the technologies to be considered first for odour treatment in a wastewater treatment or water recycling plant. When, in an economical and risk evaluation, the reliability is counted to be as relevant as the overall costs, a hybrid technology (biotrickling filtration with activated carbon polishing) would be comparable to biotrickling filtration and activated sludge diffusion as the most preferred technologies, when all technologies are designed to have a 99% reduction of H2S and a 95% reduction of the odour concentration.

Indirect Determination of Hydroxyl Radicals in Fine Particle Mist Generated from an Odor Control Technology via HPLC

Size distribution analysis of microsized water particle mist generated from an odor control technology showed the majority of particles to be in the low micron range. The indirect detection and determination of hydroxyl radicals generated by their reaction with benzene to produce phenol was performed through UV-Vis spectrophotometry (UV-Vis) and high performance liquid chromatography (HPLC). These techniques gave verification of the presence of hydroxyl radical species in the water samples collected via this odor control technology. This technology is currently being utilized at various wastewater treatment plants.

Methodology for assessing the performance of urine absorbing aids in controlling malodour release

The aim of this study was to investigate the possibility of comparing the performance of different absorbent aids in terms of odour control by discussing a suitable methodology for product evaluation. To overcome the problems of low test reproducibility owing to biological urine variability, the first step of the work consisted of the identification and the production of artificial urine having a constant and stable composition over time, moreover preventing sensorial assessors from any risk of biological contamination. Sensorial measurements were performed to optimize the similarity between artificial and biological urine, especially as far as the composition of the volatile component and therefore of the odour properties are concerned. The assessment of absorbent articles performance to control urine malodour includes both the concentration and the hedonic tone of the odour released by the article itself loaded with synthetic urine. Analyses were run on different products, which can be grouped into two different classes: absorbing aids with or without odour control technology (OCT) respectively. Results show that, despite of the presence or absence of OCT on absorbing products, their odour concentrations are almost identical, being comprised between 10000 and 12000ouE m(-3) . For this reason, it is evident that odour concentration is not suitable as the sole parameter for comparison of different absorbing products. Instead, the hedonic odour tone (odour pleasantness/unpleasantness) relevant to the different product typologies (that is products with and without OCT) should be used as an additional discriminating factor for this kind of comparative tests.

How reliable are odour assessments?

This paper will demonstrate the differences found in odour test results, when odour sampling is performed at the same sources by two different consultants. By examining two case studies, this paper will highlight that the difference between the results can be significant. Both studies are based on odour sampling programs determining the odour removal efficiency of odour control units installed at two different facilities: a pet food facility and an oil/grease recycling facility. The first study is based on odour measurements at the inlet and outlet of the unit installed by Applied Plasma Physics AS at the pet food facility. Odour assessments were performed by two separate consultants at the same time. The second study is based on testing of the odour removal effectiveness of two units: a scrubber and a biofilter at an oil/grease recycling facility. During this study two odour sampling programs were performed by two consultants at different times, but under the same process conditions. This paper will show how varying results can play a role in choosing the adequate odour control technologies. The final results suggest that although, an odour control unit may appear to be insufficient, it actually is successful at removing the odours.