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Pit recharge systems (PRS) control odor by managing organic solids in swine manure. However, there needs to be more understanding of PRS's effect on the microbiome composition and its impact on odor formation. A study was conducted to understand how recharge intervals used in PRS impact manure microbiome and odor formation. Bioreactors dynamically loaded simulated recharge intervals of 14, 10, and 4 days by diluting swine manure with lagoon effluent at varying ratios. Treatment ratios tested included 10:0 (control), 7:3 (typical Korean PRS), 5:5 (enhanced PRS #1), and 2:8 (enhanced PRS #2). Manure microbial membership, chemical concentrations, and odorant concentrations were used to identify the interactions between microbiota, manure, and odor. The initial microbial community structure was controlled by dilution ratio and manure barn source material. Firmicutes and Proteobacteria were the dominant microbial phyla in manure and lagoon effluent, respectively, and significantly decreased or increased with dilution. Key microbial species were Clostridium saudiense in manure and Pseudomonas caeni in lagoon effluent. Percentages of these species declined by 8.9% or increased by 17.6%, respectively, with each unit dilution. Microbial community composition was controlled by both treatment (i.e., manure dilution ratio and barn source material) and environmental factors (i.e., solids and pH). Microbiome composition was correlated with manure odor formation profiles, but this effect was inseparable from environmental factors, which explained over 75% of the variance in odor profiles. Consequently, monitoring solids and pH in recharge waters will significantly impact odor control in PRS. [Display omitted] • Initial microbial community composition was controlled by barn source and dilution. • Firmicutes were the dominant phylum in manure and Proteobacteria in lagoon effluent. • Manure microbial membership was impacted by solids, pH, dilution, and barn source. • Manure properties and microbes affect odor but unraveling their roles is a challenge. • Manure solids are the key manure property to monitor and control. [ABSTRACT FROM AUTHOR]

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 (H 2 S) and ammonia (NH 3). It was also found that odor gaseous loading changes corresponding to water consumption pattern in society (R2 = 0.922) for H 2 S and (R2 = 0.978) for NH 3. The highest level of 25 and 3 ppm for H 2 S and NH 3 , 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 NH 3 and H 2 S 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 NH 3 while the H 2 S 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 H 2 S and NH 3. 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. Biofiltration and chemical scrubbing are comparatively evaluated in treating actual waste gases containing H 2 S and NH 3 during a 45-day time period at a municipal WWTP in terms of environmental performance and process economics. Image 1 • Developing a chemical scrubber and a biofilter for simultaneous removal of H 2 S and NH 3. • Using the effluent of municipal wastewater treatment plant to evaluate the systems capability. • A detailed techno-economic comparison of a scrubber and a biofilter over a 45-day time period. • Suggestion of NaOCl with flow rate of 7 L/min as the best scrubbing liquid. • Achievement of high removal efficiency regardless of gas loading rate used. [ABSTRACT FROM AUTHOR]

Abstract Hazardous and odorous gas emissions from composting and methanization plants are an issue of public concern. Odor and chemical monitoring are thus critical steps in providing suitable strategies for air pollution control at waste treatment units. In this study, 141 gas samples were extensively analyzed to characterize the odor and chemical emissions released upon the aerobic treatment of 10 raw substrates and five digestates. For this purpose, agricultural wastes, biowastes, green wastes, sewage sludge, and municipal solid waste (MSW) were composted in 300 L pilots under forced aeration. Gas exhausts were evaluated through dynamic olfactometry and analytical methods (i.e., GC/MS) to determine their odor concentration (OC in OU E m−3) and chemical composition. A total of 60 chemical compounds belonging to 9 chemical families were identified and quantified. Terpenes, oxygenated compounds, and ammonia exhibited the largest cumulative mass emission. Odor emission rates (OU E h−1) were computed based on OC measurements and related to the initial amount of organic matter composted and the process time to provide odor emission factors (OEFs in OU E g−1OM 0). The composting process of solid wastes accounted for OEFs ranging from 65 to 3089 OU E g−1OM 0 , whereas digestates composting showed a lower odor emission potential with OEF fluctuating from 8.6 to 30.5 OU E g−1OM 0. Moreover, chemical concentrations of single compounds were weighted with their corresponding odor detection thresholds (ODTs) to yield odor activities values (OAVs) and odor contribution (PO i , %). Volatile sulfur compounds were the main odorants (PO i = 54–99%) regardless of the operational composting conditions or substrate treated. Notably, methanethiol was the leading odorant for 73% of the composting experiments. Graphical abstract Image 1 Highlights • Terpenes, oxygenated compounds, and ammonia were actively emitted upon composting. • Odor emission factor (OEFs) were computed for substrates treated. • Digestates composting exhibited lower odor emission potential than raw substrates. • An odor activity value (OAV) strategy was implemented. • Methanethiol and hydrogen sulfide were the major odor contributors along composting. [ABSTRACT FROM AUTHOR]

Abstract Odor emissions from swine finishing operations are an air quality issue that affects residents at the local level. A study was conducted at a commercial swine deep-pit finishing operation in central Iowa to monitor odorous compounds emitted and transported offsite. Gaseous compounds were sampled using either sorbent tubes or canisters with GC/MS analysis, and particulates matter (PM 10) were sampled with high volume samplers and thermally extracted onto sorbent tubes for GC/MS analysis. Major odorous chemical classes detected at the swine facility included volatile sulfur compounds (VSC), volatile fatty acids (VFA), phenol and indole compounds. Manure storage was the main source of odorous compounds of which hydrogen sulfide (H 2 S), methanethiol, 4-methylphenol, and 3-methylindole were key offenders. Only H 2 S and 4-methylphenol were detected above odor threshold values (OTV) at all locations around the facility and both 4-methylphenol and 3-methylindole were detected above their OTV 1.5 km downwind from the swine facility. Odorous compounds generated during agitation and pumping of the deep pits was mainly H 2 S. Odorants were mainly transported in the gas phase with less than 0.1% being associated with PM 10. Odor mitigation efforts should focus on gaseous compounds emitted from deep-pits and especially during manure agitation and deep-pit pumping. Graphical abstract Image 1 Highlights • Odor from swine operations originates predominately in manure storage areas. • Most odor is transported in the gas phase with less than 0.1% associated with dust. • Downwind transport of odor is mainly associated with indole and phenol compounds. • Hydrogen sulfide is the most significant odorant generated during agitation of manure deep-pts. [ABSTRACT FROM AUTHOR]

Abstract Nitrate-driven sulfide and ferrous oxidation have received great concern in researches on sediments odor control with calcium nitrate addition. However, interrelations among sulfide oxidation, ferrous oxidation and their associated microbes during the nitrate reduction process are rarely reported. In this work, a n NO3 /n (S+Fe) ratio (mole ratio of NO 3 − concentration to S2− and Fe2+ concentration) was first introduced as an index for calcium nitrate dosage calculation. Then certain amount of calcium nitrate was added to four sediment systems with various sulfide and ferrous initial concentration to create four gradients of n NO3 /n (S+Fe) ratio (0.6, 0.9, 1.5 and 2.0) for treatment. Furthermore, the significant variations of sulfide and ferrous oxidation, microbial diversity and community structure were observed. The results revealed that at low n NO3 /n (S+Fe) ratio (0.6 and 0.9) systems, sulfide seemed prior to ferrous to be oxidized and no obvious ferrous oxidation occurred. Meanwhile, sulfide oxidizing associated genus Sulfurimonas sp. became dominant in these systems. In contrast, sulfide and ferrous oxidation rate increased when n NO3 /n (S+Fe) ratio reached 1.5 and 2.0 (two and three times of theoretically required amount for sulfide and ferrous oxidation), which made Thiobacillus sp. more dominant than Sulfurimonas sp. Hence, when n NO3 /n (S+Fe) ratio of 1.5 and 2.0 were used, sulfide and ferrous could be simultaneously oxidized and no sulfide regeneration appeared in two months. These results demonstrated that for sulfide- and ferrous-rich sediment treatment, the nitrate consumed by ferrous oxidation should be taken into account when calculating the nitrate injecting dosage. Moreover, n NO3 /n (S+Fe) ratio was feasible as a key parameter to control the oxidation process and as an index for calcium nitrate dosage calculation. Highlights • Nitrate-driven sulfide and ferrous oxidation were separated by n NO3 /n (S+Fe) controlling. • Biological interrelation of sulfide oxidation and ferrous oxidation was revealed. • Sulfide and ferrous were simultaneously oxidized in two weeks when n NO3 /n (S+Fe) > 1.5. • n NO3 /n (S+Fe) ratio was verified a feasible index for nitrate dosage calculation. [ABSTRACT FROM AUTHOR]

Production and build-up of sulfide in wastewater systems, especially downstream of rising mains, may lead to severe odour nuisance, toxic environments and high risk of corrosion. Due to increased population migration towards cities and lower area availability for treatment facilities, rising mains for the conveyance of wastewater sludge are becoming more frequent, and research on sulfide build-up in such cases is needed. In this paper the findings of the work carried out in a full scale wastewater sludge rising main, operated during different seasons and under distinct conditions are presented (comprising both the start-up and normal operation stages of the facility). Results showed a sulfide build-up rate of 3.24 g S −2 m −2 d −1 in the summer and of 2.30 g S −2 m −2 d −1 during the winter. The ratio of sulfate reduction to sulfide production (SO 4 −2 /S −2 ) was of roughly 3 to 1, as expected. Furthermore, obtained results allowed adjusting a second order polynomial empirical equation for the forecasting of sulfide build-up within the sludge rising main. The obtained equation for sludge significantly differs from existing equations obtained for wastewater. Moreover, this work also allowed obtaining new insight into the positive influence of biofilm and hydraulic retention time in the biological sulfide generation, as well as into its variation along the length of the rising main. [ABSTRACT FROM AUTHOR]

Concentration levels and seasonal variation of odorous gases at landfill site and in surrounding areas within the city of Incheon, South Korea were investigated. Sampling was conducted at 11 points (5 at landfill site and 6 in surrounding areas). The highest concentrations of odorous gases (complex odor, ammonia, acetaldehyde, and VOCs) at landfill site were found in summer, probably due to fast decomposition of waste in high temperature related with more release of ammonia. In addition, specific weather condition of dominant wind direction, humidity and higher atmospheric pressure with no or lower wind speed caused positive effect of higher aldehyde compounds and VOCs concentration. Similar to other studies, sludge-related sampling site S-2, where a couple of odor generating facilities including sludge mixing and drying treatment process are located, showed the highest concentration levels of odorous gases compared to other sites. Odor generation frequency was in the order of acetaldehyde (68.8%) > ammonia (39.4%) > propionaldehyde (21.9%), which means the main substances generating the unpleasant odor at landfill site was recognized as aldehydes and ammonia due to combined effect of sludge-related facilities and meteorological conditions. Offensive odor was not a big pollution issue in most surrounding areas which are located within a circle of 5 km radius of the landfill except high odor generation frequency of acetaldehyde and propionaldehyde. Relative percentage differences (RPD) of odorous gases between day and night times at landfill site were below 10%, which indicates that the concentration differences in day and night were not severe. The relationship between concentrations of complex odor and designated offensive odor substances was analyzed statistically. At landfill site, the analysis shows that the correlation coefficient between the concentration of complex odor and ammonia was quite high (0.833), but it was much lower (0.129) in the surrounding areas due to considerably lower concentrations of these substances. [ABSTRACT FROM AUTHOR]

Nitrate-driven sulfide oxidation has been proved a cost-effective way to control sediments odor which has long been a universal problem for urban rivers in south China areas. In this work, sediments treatment experiments under a dynamic variation of temperature from 5 °C to 35 °C with 3% of calcium nitrate added were conducted to reveal the influence of temperature variation on this process. The results showed that microbial community was remarkably restructured by temperature variation. Pseudomonas (15.56–29.31%), Sulfurimonas (26.81%) and Thiobacillus (37.99%) were dominant genus at temperature of ≤15 °C, 25 °C and 35 °C, respectively. It seemed that species enrichment occurring at different temperature gradient resulted in the distinct variation of microbial community structure and diversity. Moreover, nitrate-driven sulfide and ferrous oxidation were proportionally promoted only when temperature increased above 15 °C. The dominant bacteria at high temperature stage were those genus that closely related to autotrophic nitrate-driven sulfide and ferrous oxidizing bacteria (e.g. Thiobacillus , Sulfurimonas and Thermomonas ), revealing that promotion of sulfide/ferrous oxidation could be attributed to the change of dominant bacteria determined by temperature variation. Thus, a higher treatment efficiency by calcium nitrate addition for odor control would be achieved in summer than any other seasons in south China areas. [ABSTRACT FROM AUTHOR]

Odor pollution has become a global environmental issue of increasing concern in recent years. Odor measurements are the basis of assessing and solving odor problems. Olfactory and chemical analysis can be used for odor and odorant measurements. Olfactory analysis reflects the subjective perception of human, and chemical analysis reveals the chemical composition of odors. As an alternative to olfactory analysis, odor prediction methods have been developed based on chemical and olfactory analysis results. The combination of olfactory and chemical analysis is the best way to control odor pollution, evaluate the performances of the technologies, and predict odor. However, there are still some limitations and obstacles for each method, their combination, and the prediction. Here, we present an overview of odor measurement and prediction. Different olfactory analysis methods (namely, the dynamic olfactometry method and the triangle odor bag method) are compared in detail, the latest revisions of the standard olfactometry methods are summarized, and the uncertainties of olfactory measurement results (i.e., the odor thresholds) are analyzed. The researches, applications, and limitations of chemical analysis and odor prediction are introduced and discussed. Finally, the development and application of odor databases and algorithms for optimizing odor measurement and prediction methods are prospected, and a preliminary framework for an odor database is proposed. This review is expected to provide insights into odor measurement and prediction. [Display omitted] • Differences in methods and panel could cause uncertainties in olfactory results. • Odor source and thresholds should be considered for chemical analysis. • Odor prediction based on odorant concentrations is a promising research direction. • Algorithms and databases are needed for optimizing odor measurement and prediction. • A preliminary framework for an odor database is proposed. [ABSTRACT FROM AUTHOR]

We examined the effects of ultrasound (U), Fenton oxidation (F), and ultrasound coupled with Fenton oxidation (U + F) pre-treatments (prior to anaerobic digestion) on the elimination of odorous compounds. The results demonstrated that U promoted odor release, while the coupled treatment and F alone decreased odor release. After 20-min treatments, the concentration of dissolved sulfide (S 2− ) under the coupled U + F treatment declined from 17.4 mg/L to 8.1 mg/L, decreasing by more than 50% and 34%, respectively, for U alone and F alone. In addition, the dissolved sulfate (SO 4 2− ) concentration under couple U + F treatment significantly increased in sewage sludge from 200 mg/L to 390.6 mg/L, up 95.3% compared to U alone and 5% compared to F alone. This illustrates the oxidation process from S 2− to SO 4 2− . Throughout experimentation, SO 4 2− was odorless and stable, highlighting the mechanism of odor control. Thus, combining U and F into a single coupled treatment proved to be a better alternative pretreatment for controlling sludge odor compared to the U and F alone and can effectively decrease potential odor release. [ABSTRACT FROM AUTHOR]

The loess regions distribute widely in Northwestern China, North America and Eastern Europe. For these regions, landfill is a suitable technology for solid waste treatment. However, as a landfill cover material, loess is not very effective in controlling the emission of malodorous gases. The present study modified loess with biologically stabilized leachate, and investigated the capacities and mechanisms of the modified loess to remove odorous NH 3 and H 2 S. The removal rates of NH 3 and H 2 S at different acclimation time, targeted gas concentrations and temperatures were measured. It was found that the NH 3 removal rate of the modified loess was up to 0.08 μmol/(g·hr), which was 1.8 times that of the virgin loess. The H 2 S removal rate of the modified loess was up to 1.74 μmol/(g·hr), which was 1.25 times that of the virgin loess. The half-meter loess layer modified by biologically stabilized leachate achieved nearly 100% removal of H 2 S. The improvement of NH 3 and H 2 S removal ability was mainly due to the enrichment of relevant microorganisms. This work proposed a novel method for in-situ control of malodorous pollutants in landfills in the loess regions, and proved that the in-situ removal of NH 3 and H 2 S using the loess modified with biologically stabilized leachate is feasible and cost-effective. [Display omitted] • An in-situ odor control method for landfills in loess regions was proposed. • Loess was modified with biologically stabilized leachate for landfill cover. • Microbes and functional genes for odor control were enriched after modification. • The highest NH 3 removal rate of loess was increased by 80% after modification. • The highest H 2 S removal rate of loess was increased by 25% after modification. [ABSTRACT FROM AUTHOR]

Past water distribution systems (WDS) management studies derived operation protocols to maximize WDS reliability by using residual chlorine as the sole surrogate parameter for water quality reliability. Albeit the advancement in mechanistic modeling to examine the WDS water quality, emerging water quality parameters of concern are not yet involved in solving WDS management problems. This paper attempts to overcome this limitation by developing a flexible decision-making framework -integrating EPANET-C, a mechanistic modeling tool for WDS water quality, with Analytic Hierarchy Process (AHP), a multi-criteria decision-making method - to rank the possible water quality parameter-based operating alternatives (organic matter and residual chlorine levels at the source points) for WDS. The uncertainty analysis was incorporated into the mechanistic modeling using the Monte Carlo method to realize insufficient knowledge about the complex biological and physicochemical interactions inside WDS. Six cases, each ranking the alternatives diversely, were applied to reflect the expert judgment impressions on the AHP outcomes. The consistency of the proposed decision-making framework was verified by deriving the operation protocol for two test networks by making trade-offs between the multiple and conflicting microbiological, chemical, and organoleptic quality criteria. The disinfection by-products formation control and taste and odor problems control emerged as the most critical water quality criteria determining the WDS performance under the operating alternatives examined. Altogether, the obtained results suggested the practicality of adopting a flexible operation protocol to maintain the water quality benchmarks over various plausible WDS performance scenarios, ranging from worst to best. [Display omitted] • General methodology to derive operation protocols for water distribution systems. • All-inclusive water distribution systems quality modeling considering uncertainty. • Flexible decision-making framework based on analytic hierarchy process. • Chemical and organoleptic quality criteria control the hierarchization process. • Flexible operation protocol minimizes contamination risks during operation. [ABSTRACT FROM AUTHOR]

In this study, the evolution of odour concentration (ou E /m 3 STP ) emitted during the pile composting of the organic fraction of municipal solid waste (OFMSW) was monitored by dynamic olfactometry. Physical–chemical variables as well as the respirometric variables were also analysed. The aim of this work was twofold. The first was to determine the relationship between odour and traditional variables to determine if dynamic olfactometry is a feasible and adequate technique for monitoring an aerobic stabilisation process (composting). Second, the composting process odour impact on surrounding areas was simulated by a dispersion model. The results showed that the decrease of odour concentration, total organic carbon and respirometric variables was similar (around 96, 96 y 98% respectively). The highest odour emission (5224 ou E /m 3 ) was reached in parallel with the highest microbiological activity (SOUR and OD 20 values of 25 mgO 2 /gVS·h and 70 mgO 2 /gVS, respectively). The validity of monitoring odour emissions during composting in combination with traditional and respirometric variables was demonstrated by the adequate correlation obtained between the variables. Moreover, the quantification of odour emissions by dynamic olfactometry and the subsequent application of the dispersion model permitted making an initial prediction of the impact of odorous emissions on the population. Finally, the determination of CO 2 and CH 4 emissions allowed the influence of composting process on carbon reservoirs and global warming to be evaluated. [ABSTRACT FROM AUTHOR]

Emission of odours during the thermal drying in sludge handling processes is one of the main sources of odour problems in wastewater treatment plants. The objective of this work was to assess the use of the response surface methodology as a technique to optimize the chemical conditioning process of undigested sewage sludges, in order to improve the dewaterability, and to reduce the odour emissions during the thermal drying of the sludge. Synergistic effects between inorganic conditioners (iron chloride and calcium oxide) were observed in terms of sulphur emissions and odour reduction. The developed quadratic models indicated that optimizing the conditioners dosage is possible to increase a 70% the dewaterability, reducing a 50% and 54% the emission of odour and volatile sulphur compounds respectively. The optimization of the conditioning process was validated experimentally. [ABSTRACT FROM AUTHOR]

Two down-flow wood bark-based biofilters were evaluated for their effectiveness in treating odor, NH3 and H2S under actual swine farm conditions. The water requirement for maintaining proper media moisture contents (MC) under different ventilation rates and intervals were determined. The effect of media depth and MC on the biofilters' performance was also evaluated. The aerodynamic resistance on biofilters was studied using computational fluid dynamics (CFD) software. Water requirements for biofilters were obtained in the range of 3.8–556.0 L/m 3 /d for ventilation duration of 1–24 h/d (depending on the age of the pig and environmental conditions). The highest reductions in odor, NH3 and H2S, obtained in this study at empty bed residence times (EBRT) of 1.6–3.1 s, were 73.5–76.9%, 95.2–97.9% and 95.8–100.0%, respectively. The pressure drop was 28.8–68.8 Pa for a media depth of 381 mm at an EBRT of 1.6–3.1 s and an MC of 64–65%. The pressure drop followed a secondary order polynomial line with both airflow rate and media MC ( R2 = 0.927–0.982). The results of odor, NH3 and H2S reduction efficiency and pressure drop suggest a media depth of ≥254 mm, MC ≥ 35–50% and EBRT of 2–3 s for successful operations of the wood bark-based biofilters. A high correlation was found between the measured and predicted pressured drops obtained using CFD software (R2 = 0.921, RMSE = 0.145). [ABSTRACT FROM AUTHOR]

Treatment of ventilation air from livestock production by biological airfiltration has emerged as a cost-effective technology for reduction of emissions of odorants and ammonia. Volatile sulfur compounds from livestock production include H2S and methanethiol, which have been identified as potentially important odorants that are not removed sufficiently by biological air filters. Light-expanded clay aggregates (Leca®) is a biotrickling filter material that contains iron oxides, which can oxidize H2S and methanethiol, and thus potentially may help to remove these two compounds in biological air filters. This study used on-line PTR-MS measurements to investigate the performances of two Leca® biotrickling filters (abraded Leca® filter and untreated Leca® filter) for removal of odorants and ammonia emitted from an experimental pig house. The results indicated that the abraded Leca® filter had a similar or slightly better capability for removing odorants than the untreated Leca® filter. This may be due to the enlargement of the surface area by the friction process. The volatile sulfur compounds, however, were not removed efficiently by either of the two Leca® filters. Kinetic analysis of a ventilation controlled experiment during the first period indicated that Grau second-order kinetics could be applied to analyze the removal of sulfur compounds and other odorants, whereas the Stover-Kincannon model could only be applied to analyze the removal of odorants other than sulfur compounds, partly due to the limitation of mass transfer of these compounds in the biotrickling filters. In the last measurement period, a production of dimethyl disulfide and dimethyltrisulfide coinciding with strongly enhanced removal of methanethiol was observed for the untreated filter. This was assumed to be enhanced by an incidence of low local air velocity in the filter and indicated involvement of iron-catalyzed reactions in the removal of sulfur compounds. [Copyright &y& Elsevier]

This research focuses on the identification and quantification of odorous components in rendering plant emissions by GC/MS and other analytical methods, as well as the description of phenomena occurring in biofilter in order to improve the removal efficiency of industrial biofilters. Among the 36 compounds quantified in the process air stream, methanethiol, isopentanal and hydrogen sulfide, presented the major odorous contributions according to their high concentrations, generally higher than 10 mg m−3, and their low odorous detection thresholds. The elimination of such component mixtures by biofiltration (Peat packing material, EBRT: 113 s) was investigated and revealed that more than 83% of hydrogen sulfide and isopentanal were removed by biofilter. Nevertheless, the incomplete degradation of such easily degradable pollutants suggested inappropriate conditions as lack of nutrients and acidic pH. These inadequate conditions could explain the lack of performance, especially observed on methanethiol (53% of RE) and the production of oxygenated and sulfur by-products by the biofilter itself. [Copyright &y& Elsevier]

Abstract: Lagoons are widely used in rural area for wastewater treatment; however, the odor problem has hampered its application. The root of odor emission from lagoons varies from one to another. The key of controlling the odor is to find out the cause and accordingly provide strategies. Various physical, chemical, and biological methods have been reported and applied for odor control. Physical technologies such as masking, capturing and sorption are often employed to mitigate the pressure from compliant while not to cut off the problem. Chemical technologies which act rapidly and efficiently in odor control, utilize chemicals to damage the odorant production root or convert odorant to odorless substances. Biological methods such as aeration, biocover and biofiltration control the odor by enhancing aerobic condition or developing methanogens in lagoon, and biologically decomposing the odorants. Comparing to physical and chemical methods, biological methods are more feasible. [Copyright &y& Elsevier]

Gases released from landfill sites into the atmosphere have the potential to cause olfactory nuisances within the surrounding communities. Landfill sites are often located over complex topography for convenience mainly related to waste disposal and environmental masking. Dispersion of odours is strongly conditioned by local atmospheric dynamics. Assessment of odour impacts needs to take into account the variability of local atmospheric dynamics. In this study, we discuss a method to assess odour impacts around a landfill site located over complex terrain in order to provide information to be used subsequently to identify management strategies to reduce olfactory nuisances in the residential neighbourhoods. A weather-type classification is defined in order to identify meteorological conditions under which olfactory nuisances are to be expected. A non-steady state Gaussian model and a full-physics meteorological model are used to predict olfactory nuisances, for both the winter and summer scenarios that lead to the majority of complaints in neighbourhoods surrounding the landfill site. Simulating representative scenarios rather than full years make a high resolution simulation of local atmospheric dynamics in space and time possible. Results underline the key role of local atmospheric dynamics in driving the dispersion of odours. The odour concentration simulated by the full-physics meteorological model is combined with the density of the population in order to calculate an average population exposure for the two scenarios. Results of this study are expected to provide helpful information to develop technical solutions for an effective management of landfill operations, which would reduce odour impacts within the surrounding communities. [Copyright &y& Elsevier]

Landfilling is the most common option for solid waste disposal worldwide. Landfill sites can emit significant quantities of greenhouse gases (GHGs; e.g., methane, carbon dioxide, and nitrous oxide) and release toxic and odorous compounds (e.g., sulfides). Due to the complex composition and characteristics of landfill surface gas emissions, the quantification and control of landfill emissions are challenging. This review attempts to comprehensively understand landfill emission quantification and control options by primarily focusing on GHGs and odor compounds. Landfill emission quantification was highlighted by combining different emissions monitoring approaches to improve the quality of landfill emission data. Also, landfill emission control requires a specific approach that targets emission compounds or a systematic approach that reduces overall emissions by combining different control methods since the diverse factors dominate the emissions of various compounds and their transformation. This integrated knowledge of emission quantification and control options for GHGs and odor compounds is beneficial for establishing field monitoring campaigns and incorporating mitigation strategies to quantify and control multiple landfill emissions. • Quantification and control approaches of landfill gas (LFG) emissions are reviewed. • Point flux determination is simple often fails to identify hotspots and overall landfill emissions. • Emissions quantification for large landfills is improved by combining with measurement techniques. • Appropriate biocover and landfill operation can control multiple LFG emissions. [ABSTRACT FROM AUTHOR]

Open anaerobic lagoons are widely used for liquid manure storage and treatment, with excess greenhouse gas (GHG) and odor emissions. In this study, liquid manure was valorized through hybrid nitrogen and phosphorous recovery as value-added products using an airlift reactor. Also, the organic load of liquid manure was reduced before discharging into anaerobic lagoons, which simultaneously mitigated GHG emissions. The results showed that 14.5% of total nitrogen (TN) was recovered as ammonium sulfate, while 38.8% of TN and 79.3% of total phosphorus (TP) were recovered as phosphorus-rich sludge. After the pre-treatment in the reactor, the odor could be controlled effectively due to a 94.2% decrease in total VFAs. In addition, 59.0% of COD was removed, which decreased the theoretical modeled GHG emissions by 51.7% compared to the traditional direct discharging. The application is promising for upgrading anaerobic lagoons of liquid manure. [Display omitted] • Anaerobic lagoon of animal liquid manure could be upgraded through airlift reactors. • 79.3% of TP and 38.8% of TN were recovered as Phosphorus-rich sludge. • 14.5% of TN was recovered as ammonium sulfate. • GHG emissions reduction from the suggested modification was estimated to be 51.7%. • COD and total VFAs were removed by 59.0% and 94.2%, respectively. [ABSTRACT FROM AUTHOR]