Sulfide Emissions Research Articles

System of localized excitons on oxygen complexes in CdS

Intense CdS luminescence in the blue and green spectral regions is widely used in all areas of optoelectronics. In this spectrum band are working on lasers CdS. This paper presents the results of a study of the exciton region of the CdS spectrum based on the theory of anti-intersecting bands (bands anticrossing theory-BAC) with the involvement of broader initial data for the analysis of optical properties. Depending on the growth conditions, the presence and change of oxygen concentration and intrinsic point defects determining the composition of crystals are taken into account. The concept of the nonuniform distribution of isoelectronic oxygen centers in the bulk of CdS due to their predominant segregation on compensating stacking faults is introduced. Cathodoluminescence (CL) spectra were studied using various recording methods, excitation intensity and temperature, as well as pulsed CL at high excitation intensities. In a scanning electron microscope from local registration and a high excitation density, the emission of the edge luminescence components of CdS was detected at 300 K. To analyze the optical data, we used the capabilities of the method for constructing band models based on the BAC theory, which collects extensive and multilateral information about specific samples. A model of a CdS · O multizone with stacking faults, which determines the spectrum of edge emission is presented. An explanation of the nature of the green edge emission of cadmium sulfide as excitons localized on oxygen-containing complexes in SF layers has been obtained for the first time. It was found that the system of levels of localized excitons at stacking faults does not change either with temperature up to 300 K, or with a change in the oxygen solubility in the crystal to the limiting one. It is shown that the presence of isoelectronic oxygen centers appear itself in the electro-physical properties of crystals. Recommendations are given for the diagnostics of crystals suitable for the creation of luminescent systems or lasers that are stable in operation. Keywords: isoelectronic centers, bands anticrossing theory, localized exciton, stacking faults, point defects, stimulated radiation.

Carbon disulphide and hydrogen sulphide emissions from viscose fibre manufacturing industry: A case study in India

CS 2 and H 2 S emissions are the most prominent environmental footprint of viscose fibre manufacturing industry and this necessitates periodical assessment of their emission load from this sector. Emission factors of CS 2 and H 2 S from viscose fibre manufacturing were determined by conducting in-plant emission assessments in three viscose fibre manufacturing plants (one viscose filament yarn and two viscose staple fibre plants) in India. The CS 2 and H 2 S emission factors were estimated to be 284.03 and 20.9 kg MT -1 (i.e. metric ton or tonne) of viscose fibre (viscose filament yarn or VFY) and 99.64 and 33.15 kg MT -1 of viscose fibre (viscose staple fibre or VSF), respectively. Indian and global CS 2 and H 2 S emission estimates from viscose fibre manufacturing sector were prepared by incorporating these newly developed emission factors. Annual emissions from Indian VSF sector in 2020 were estimated to be 78.32 Gg CS 2 and 26.06 Gg H 2 S while from VFY sector, the same were 15.30 Gg and 1.13 Gg. This signifies an upward revision of the 2001 estimate of 26.8 Gg CS 2 emitted from the entire Indian industrial sector, including viscose fibre manufacturing sector. Further, using the newly developed emission factors for VSF and available global viscose fibre production data of 2017, global annual CS 2 and H 2 S emissions were estimated to be 577.9 Gg and 192.3 Gg, respectively, in 2017 that were predominantly contributed by China and India due to their dominant share in global viscose fibre production, followed by Thailand, Indonesia and Austria. • Emission factors of CS 2 and H 2 S from viscose fibre manufacturing are developed. • In 2020, Indian viscose staple fibre sector emitted 78.32 Gg CS 2 & 26.06 Gg H 2 S. • In 2020, Indian viscose fibre yarn sector emitted 15.30 Gg CS 2 & 1.13 Gg H 2 S. • In 2017, Global CS 2 and H 2 S emissions were estimated to be 577.9 Gg and 192.3 Gg. • China (65.74%) & India (11.11%) had maximum share in global CS 2 & H 2 S emissions.

Molten salt gasification characteristics of various organic waste fuels for HF-DCFC

With fossil fuel prices soaring due to the Ukraine crisis, countries must not only achieve energy self-sufficiency in the future, but also curb CO2 emissions to prevent global warming. In order to achieve both of these goals, our laboratory has been developing a High Functional Direct Carbon Fuel Cell (HF-DCFC) composed of a molten salt gasification and a Tubular Molten Carbonate Fuel Cell. HF-DCFC can generate electricity directly using various organic wastes as fuel, but the previous study was elucidated that its cell performance is greatly affected by the fuel type. In this study, the gasification characteristics of polyethylene (PE), wood pellets (WP), and onion peels (ONION) were investigated for the installation of HF-DCFCs in each community as a waste treatment generator. As a result, the highest CO and H2 production as fuel for HF-DCFC occurred with WP under 70(25CO2/75N2)/30H2O atmosphere. PE produced hardly CO and H2 productions, but high sulfide emissions. ONION gasification produces CO and H2 second only to WP with little CH4 production, but gasification characteristics were greatly enhanced when ONION was wrapped in PE and fed. Moreover, in all fuels, the addition of air inhibits the formation of fuel gas through partial oxidation reactions and reduces gasification efficiency but increases energy efficiency because the oxidation reactions raise the temperature of the molten salt.

Диффузия канализационного сероводорода в атмосферном воздухе

This article considers the problem of the atmospheric air pollution by hydrogen sulfide emissions from facilities at sewer networks and substantiates the necessity to take these emissions into account as sources of impact. The author assesses the possibility of using various mathematical modeling methods to calculate the dispersion of emissions from such structures as ground-based sources of small capacity. An energy dissipation chamber was selected as a full-scale object in the study. Comparison of the results of the simulation obtained at the Main Geophysical Observatory, OND-86, Gaussian model and finite-element analysis in ANSYS CFX with the results of in-situ measurements has shown the greatest efficiency of the latter method.

Effects of probiotic mixed environmental improvement agent feeding and spreading on ammonia and hydrogen sulfide emission from Hanwoo manure

The aim of this study was to investigate the effects of probiotic mixed environment improvement agent feeding and spreading on ammonia and hydrogen sulfide emissions of Hanwoo manure. Three animals were allocated to each pen as an experimental unit. An experiment was performed with three replicates as a complete randomized design and treatments were assigned a control group and a mixed environment improvement agent group. In the result of the feeding trial, at 60 days, ammonia gas emission from Hanwoo manure was significantly lower content in the probiotics mixed environment improvement agent group than in the control group (p = 0.027), hydrogen sulfide gas emission from Hanwoo manure tends to be lower in the probiotics mixed environment improvement agent group than in the control group (p = 0.085). At the 5-day point of the spreading trial, ammonia gas emission from Hanwoo manure was significantly lower in the probiotics mixed environment improvement agent group than in the control group (p = 0.001). As a result, probiotic mixed environment improvement agents could be helpful in lowering the concentrations of odor substances in a farm.

Applied Research Note: Evaluation of a Bacillus-based direct-fed microbial as a strategy to reduce hydrogen sulfide emissions from poultry excreta using a practical monitoring method

Effective implementation of noxious odor mitigation strategies requires a thorough understanding of production causes, a clear definition of harmful odor limits, and practical and effective methods to measure emissions into the environment. With the increasing demand for poultry products and consequently, intensification of production systems, there is a need for versatile odor remediation approaches. Hydrogen sulfide ( H 2 S ) is a pungent noxious gas associated with poultry farms. The presence and intensity of H 2 S from animal excreta is the result of the dynamic balance of its formation and reduction, under primarily anaerobic microbial fermentation conditions. Unlike other odors such as ammonia, H 2 S production and emission is a less researched subject. In the present study, a practical monitoring method was devised to evaluate the efficacy of a Bacillus -based microbial product as a strategy to remediate H 2 S emissions from poultry excreta. The evaluated excreta were preconditioned with distilled water and then incubated for 24 h under controlled temperature before odor measurement. Plastic containers were used as incubation units, and H 2 S diffusion tubes were used as the monitoring tool. Hydrogen sulfide emitted from the excreta of broilers fed the microbial product was reduced on average by 42.9% compared to a nonmicrobial fed group. Under the current trial conditions, H 2 S emitted from growing broiler chicken excreta was easily detectable and variation was low. Moreover, the method allowed dynamic and quick H 2 S monitoring that will further offer tools to the commercial poultry industry for evaluating the effectiveness of feeding strategies in odor remediation.

Predicting H2S emission from gravity sewer using an adaptive neuro-fuzzy inference system

Abstract A predictive model to estimate hydrogen sulfide (H2S) emission from sewers would offer engineers and asset managers the ability to evaluate the possible odor/corrosion problems during the design and operation of sewers to avoid in-sewer complications. This study aimed to model and forecast H2S emission from a gravity sewer, as a function of temperature and hydraulic conditions, without requiring prior knowledge of H2S emission mechanism. Two different adaptive neuro-fuzzy inference system (ANFIS) models using grid partitioning (GP) and subtractive clustering (SC) approaches were developed, validated, and tested. The ANFIS-GP model was constructed with two Gaussian membership functions for each input. For the development of the ANFIS-SC model, the MATLAB default values for clustering parameters were selected. Results clearly indicated that both the best ANFIS-GP and ANFIS-SC models produced smaller error compared with the multiple regression models and demonstrated a superior predictive performance on forecasting H2S emission with an excellent R2 value of >0.99. However, the ANFIS-GP model possessed fewer rules and parameters than the ANFIS-SC model. These findings validate the ANFIS-GP model as a potent tool for predicting H2S emission from gravity sewers.

Adsorption of Hydrogen Sulfide (H2S) from Municipal Solid Waste by Using Biochars

The emission of hydrogen sulfide (H2S) from municipal solid waste is one of the environmental issues that raised the public’s attention and awareness. Exposure to H2S that brings a foul smell of rotten eggs will cause headaches, irritation, dizziness, fatigue, and even death if the concentration of H2S is too high. The study’s goals are to investigate the properties of biochars made from rice hulls, banana peels, and sawdust; to compare the biochars’ physical and chemical properties; and establish the H2S removal efficiency of the three biochars. Biochars derived from rice hull (RHB-500), banana peel (BPB-550), and sawdust (SDB-500) by pyrolysis were used as the adsorbents. The biochar yield, pH, ash content, surface functional group, and morphology of the biochars produced were investigated. In this study, H2S was synthesized by mixing food waste and soil in the experimental column. The H2S produced was reduced by the adsorption method. The removal efficiencies of H2S for each biochar were determined by allowing the synthetic H2S to flow through the two columns that were packed with sand (act as control) and biochars, respectively. All biochars were alkaline, and BPB-550 had the highest pH, followed by SDB-500 and finally RHB-500. The order for removal efficiency of H2S (>94%) is BPB-550 > SDB-500 > RHB-500. Overall, the biochars derived from biomass had a strong ability to act as the adsorbents for H2S removal.

Effect of Rotten Butter Shock Load on Anaerobic Digestion of Chicken Manure

Anaerobic digestion is a popular method for improving fertilizing properties, but there is no report on the effect of shock load with butter on anaerobic digestion of chicken manure. Therefore, this study aimed to investigate the anaerobic digestion of chicken manure with butter addition. The volatile suspended solid (VSS) was set at 20g VSS/L with different butter additions from 0 to 60 g VSS/L and different oxygen flow rate (OFR) from 0 to 2.5 mL/h. The results showed that ammonia ranged from 0.072 g/L to 0.082 g/L, while the volatile acids ranged from 425 mg/L to 325 mg/L. The volatile organic acid was significantly influenced by a change in OFR compared to ammonia, while a correlation between hydrogen and hydrogen sulfide was observed. The results showed that the highest hydrogen and methane production was obtained at butter addition of 30 g VSS/L with OFR 1.4 mL/h with volumes of 78 mL and 25 L respectively. In addition, hydrogen sulfide emissions induced rapid growth with increase in butter concentration.

The CHIMERE v2020r1 online chemistry-transport model

Abstract. The CHIMERE chemistry-transport model v2020r1 replaces the v2017r5 version and provides numerous novelties. The most important of these is the online coupling with the Weather Research and Forecasting (WRF) meteorological model via the OASIS3 – Model Coupling Toolkit (MCT) external coupler. The model can still be used in offline mode; the online mode enables us to take into account the direct and indirect effects of aerosols on meteorology. This coupling also enables using the meteorological parameters with sub-hourly time steps. Some new parameterizations are implemented to increase the model performance and the user's choices: dimethyl sulfide (DMS) emissions, additional schemes for secondary organic aerosol (SOA) formation with volatility basis set (VBS) and H2O, improved schemes for mineral dust, biomass burning, and sea-salt emissions. The NOx emissions from lightning are added. The model also includes the possibility to use the operator-splitting integration technique. The subgrid-scale variability calculation of concentrations due to emission activity sectors is now possible. Finally, a new vertical advection scheme has been implemented, which is able to simulate more correctly long-range transport of thin pollutant plumes.

Bacterial epiphyte and endophyte communities of seagrass Thalassia hemprichii: the impact of feed extract solution.

The global seagrass bed ecosystem acts as a natural ecological barrier in the littoral coastal zone. In recent years, this ecosystem has suffered from serious eutrophication and destruction caused by the continuous expansion of aquaculture. However, our understanding of the influence of aquaculture on the bacterial community remains limited. In this study, we used 16S amplicon sequencing to evaluate the impact of aquaculture feed extract solution on the composition and function of bacterial epiphytes and endophyte communities of the core seagrass from the seagrass bed ecosystem in Hainan, Thalassia hemprichii. The feed extract solution was the main factor that significantly affected the bacterial epiphyte and endophyte community structure of seagrass leaves but had no marked effect on alpha diversity was observed. Additionally, the bacterial epiphyte and endophyte community of the T. hemprichii leaves alleviated the effects of organic matter, sulfide, and nutrients caused by aquaculture wastewater. The feed extract solution promoted the proliferation of Bacteroidales, Vibrio, Desulfobulbaceae, Desulfobacteraceae, Pseudoalteromonas, Paludibacter, Marinomonas, and Pseudomonas in the leaves and root of T. hemprichii, which can effectively improve the digestibility of eutrophication. In fact, Desulfobacteraceae and Desulfobulbaceae can reduce sulfate to sulfide and oxidize sulfide to sulfur within seagrass, indicating that the increase in Desulfobulbaceae and Desulfobacteraceae facilitated the accumulation of sulfide with the treatment of feed extract solution, which may be the reason for the degradation of seagrass caused by aquaculture wastewater containing high concentrations of organic pollutants. These results suggest that although seagrass beds can withstand low concentrations of aquaculture pollutants, sulfide emissions should be minimized.

Effects of natural and anthropogenic emissions on the composition and toxicity of aerosols in the marine atmosphere

The impacts of natural dimethyl sulfide (DMS) and ship emissions on marine environments and particulate matter (PM) over the western and southern sea areas around South Korea were studied based on field campaigns from August–September 2017 and May–June 2018 using the Community Multi-scale Air Quality v5.3.2 modeling system. DMS oxidation enhanced the concentrations of both sulfur dioxide (SO2) and sulfate (SO42−) in PM2.5 by 6.2–6.4% and 2.9–3.6%, respectively, in the marine atmosphere during the study period, whereas it slightly decreased nitrate (NO3−) concentrations (by −1.3%), compared to the simulation without DMS oxidation chemistry. Furthermore, ship emissions increased the concentrations of SO42−, NO3−, and NH4+ by 4.5%, 23%, and 7.3%, respectively. Methane sulfonic acid concentration was 0.17 μg m−3, suggesting the importance of the addition channel in the DMS oxidation pathway. The model simulation indicated that ship emissions in the target area contributed dominantly to non-sea-salt SO42−, and the marine DMS emission source was non-negligible. The geographical distribution of PM toxicity (aerosol oxidative potential) was assessed in the marine atmosphere during the study period.

CFD modeling of different mass transfer coefficients on hydrogen sulfide emission in a flux chamber.

Hydrogen sulfide (H2S) is commonly used as an indicator for odorous gas emission monitoring in wastewater treatment plants. The H2S emission estimations can be performed using algebraic mathematical models or carrying out measurements at the source, with the dynamic flux chamber, for example. This work brings together these two methodologies in a computational fluid dynamics analysis. Fifteen liquid-phase mass transfer coefficient ([Formula: see text]) models were initially evaluated in establishing, at the liquid-gas interface in a flux chamber, an H2S emission flux based on the friction velocity field from three different inlet flows (2, 5, and 10 L min-1). Ten [Formula: see text] models were fully simulated, and the numerical results were compared with available experimental data. The higher the inlet flow, the higher the friction velocity at the interface, and the higher the H2S emission. The H2S emission was also strongly dependent on the constant coefficients of the existing [Formula: see text] models. Small variability on those coefficients generates considerable changes in emissions at the interface. Few and different models performed well in describing the available concentration data at the outlet sampling probe for different inlet flows, which shows there is still no single model capable of representing all simulated friction velocity ranges (0.005 to 0.017ms-1).

Improved effect of manure acidification technology for gas emission mitigation by substituting sulfuric acid with acetic acid

Animal manure is a significant source of ammonia, methane, hydrogen sulfide, and odor emissions. Manure acidification to pH 5.5 using sulfuric acid (H2SO4) is an approved method for reducing ammonia and methane emissions from barns and retaining bioavailable nitrogen in the slurry for subsequent field fertilization. However, the use of H2SO4 may increase the emission of malodorous sulfur compounds and reduces subsequent biogas production. In this study, we investigated if substituting a part of the H2SO4 treatment with acetic acid (CH3COOH) improves manure emissions. In two experiments, cattle manure was incubated for 11 days each and acidified daily with either i) H2SO4 (4M) or CH3COOH (4M), or ii) mixes of both acids (4M H2SO4 + 8M CH3COOH, in volume ratios of 75:25, 50:50, and 25:75) until pH 5.5. The emission of ammonia, methane, hydrogen sulfide, and volatile organic compounds (VOCs) was monitored continuously. At the end of both experiments, cumulative ammonia emission was reduced by 75% by H2SO4 and by 83% by CH3COOH, indicating that CH3COOH was more efficient. Acetic acid almost completely eliminated CH4 emission, while H2SO4 reduced CH4 emission by 89%. Furthermore, CH3COOH acidification resulted in lower odorant emissions compared to H2SO4. Based on the second experiment, we recommend using a high percentage of CH3COOH during the first days of acidification, followed by a mix containing at least 50% CH3COOH, to achieve a high mitigation efficiency with a lower emission of sulfur compounds compared to H2SO4 alone.

Comparison of H2S Gas Sensors: A Sensor Management Procedure for Sewer Monitoring

Hydrogen sulphide (H2S) emissions are one of the major problems associated with sewer networks. This gas, with its characteristic smell of rotten eggs is highly toxic and leads to the corrosion of sewer infrastructures. To protect cities and ensure the safety of sewer workers, sewers are commonly monitored using H2S gas sensors. In this work, three commercial H2S gas sensors for air quality monitoring were compared at two different sites in Berlin, Germany. Two of the sensors provide online access to data, while the other one is a data logger. Moreover, based on statistical measures (RMSE, MAE, MB, and a graphical analysis), we evaluated whether a rotation/exchange between data logger (reference) and online sensors is possible without significant differences in the gas measurements. Experimental evaluation revealed that measurement differences are dependent on the H2S concentration range. The deviation between sensors increases as the H2S concentration rises. Therefore, the interchange between reference and online sensors depends on the application site and the H2S levels. At lower ranges (0–10 ppm) there were no observed problems. Finally, to support practitioners on-site, a management procedure in the form of a decision-making tool is proposed for assessing whether gas sensors should be exchanged/rotated.

Sodium butyrate reduce ammonia and hydrogen sulfide emissions by regulating bacterial community balance in swine cecal content in vitro

Reducing the production of odor during swine breeding has attracted attention. Ammonia (NH3) and hydrogen sulfide (H2S) contributed to the odor emissions from swine breeding because NH3 emissions are high and hydrogen sulfide (H2S) has a low odor threshold. Sodium butyrate reduces the odor emissions caused by NH3 and H2S, but the corresponding mechanism is unclear. After mixing the feces of six fattening pigs, the mixture was used to process in vitro fermentation experiment. The purpose was researching the effect of sodium butyrate reduced NH3 and H2S emissions in swine cecal contents. The control group was denoted CK, and the treatment groups with different sodium butyrate concentrations (0.015%, 0.030% and 0.150%) were denoted L, M and H. The NH3, H2S, total gas production and physicochemical indexes were measured, and the bacterial communities in the fermented product were analyzed by 16 S rDNA sequencing. The results showed that group M reduced NH3, H2S and total gas production by 17.96%, 12.26% and 30.30%, respectively. Sodium butyrate promoted SO42- accumulation and lowered the pH. Importantly, sodium butyrate decreased the relative abundance of bacteria positively correlated with NH3 and H2S production, but increased the negatively correlated ones. Proteobacteria made a greater contribution to reducing emissions than did other bacterial phyla. Our results showed that adding 0.030% sodium butyrate can significantly reduce NH3 and H2S production, which occurred via alterations in the physicochemical indicators to adjust the abundance of the bacteria related to odor production, including Proteobacteria.

Hydrogen sulfide occurrence states in China's coal seams

The occurrence states of hydrogen sulfide in coal seams are crucial in preventing and controlling hydrogen sulfide emission in coal mines and the safe development of coal bed methane. In this study, the research status of the occurrence states of free-state, adsorbed-state, and water-soluble hydrogen sulfide in coal seams was systematically analyzed. H2S anomaly areas in China's coal seams are mainly located in the Carboniferous-Permian and Jurassic series of northern, eastern, central, and northwest regions of China. Bacterial sulfate reduction accounts for most of the hydrogen sulfide anomalies of low-rank coal, while thermochemical decomposition thermal desorption spectroscopy and thermochemical sulfate reduction may also result in hydrogen sulfide anomaly in medium- and high-rank coal. In contrast, magmatism-induced hydrogen sulfide anomalies are rarely found. Absorbed-state hydrogen sulfide anomalies are prevailing, while water-soluble and free-state hydrogen sulfide anomalies are relatively scarce. Coal seam's porosity mainly controls the hydrogen sulfide adsorption, pressure, coalification degree, pore volume, and specific area, while water-soluble hydrogen sulfide is influenced by pressure, sulfate-reducing bacteria, burn, porosity, fractures, water temperature, and hydrodynamic conditions. The fractures in coal seams, their burial depth, coal quality, coal rank, roof, and floor lithology are the main factors controlling the free-state hydrogen sulfide preservation. The absorbed-state hydrogen sulfide in coal seams is mainly mitigated by varying the ventilation mode, increasing the ventilation capacity, spraying alkali fog into the air, and injecting alkali liquid into coal seams for governance.

Bacterial dynamics for gaseous emission and humification in bio-augmented composting of kitchen waste

Using high-throughput sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX), this study aimed to elucidate the effect of bacterial dynamics on gaseous emission and humification of kitchen and garden wastes during composting augmented with microbial inoculants. Microbial inoculant addition at up to 0.9% resulted in a diverse bacterial community with more functional bacteria to amend gaseous emission and enhance humification. Microbial inoculation facilitated the enrichment of aerobic bacteria (e.g. the genus Bacillus and Thermobifida) to enhance cellulolysis and ligninolysis to advance organic humification. By contrast, several bacteria, such as the genus Weissella and Pusillimonas were inhibited by microbial inoculation to weaken fermentation and nitrate respiration. As such, bio-augmented composting with 0.9% microbial inoculant reduced the emission of methane by 11–20% and nitrogen oxide by 17–54%. On the other hand, ammonia and hydrogen sulphide emissions increased by 26–62% and 5–23%, respectively, in bio-augmented composting due to the considerable proliferation of the genus Bacillus and Desulfitibacter to enhance ammonification and sulphur-related respiration. Results from this study highlight the need to further develop efficient and multifunctional microbial inoculants that promote humification and deodorization for bio-augmented composting of kitchen waste as well as other carbon and nutrient rich organic wastes.

Variation in hydrogen sulfide emissions from a U.S. Midwest anaerobic dairy lagoon.

Hydrogen sulfide (H2 S) emissions from midwestern United States dairy anaerobic waste lagoons are episodic and seasonal. Emissions were modeled using an inverse diffusion model in conjunction with measured concentrations and turbulence. The potential for lagoon mixing was estimated by the Brunt frequency using a theoretical Fourier series temperature profile model constructed from measured air and lagoon temperatures. Annual H2 S emissions from the dairy parlor and holding area liquid waste, based on 318 d of measurement, were 212g m-2 or 807g head of cattle-1 . Hydrogen sulfide emissions were highest in the spring and the fall. Eleven days with emissions >7g d-1 head-1 accounted for 25% of the annual emissions. Shear mixing appeared to dominate the mixing in the lagoon when the lagoon was estimated to be nearly isothermal. Wind shear correlated with significantly greater daily mean emissions. The H2 S emissions from this lagoon appeared to result from a series of processes; biogenic production of H2 S in the sludge, H2 S-enriched bubbles rise through the lagoon by buoyancy and wind shear induced mixing, and bubbles bursting at the surface either due to desiccation of the bubbles or surface disturbances induced by wind and precipitation.

Bioaugmentation mitigates ammonia and hydrogen sulfide emissions during the mixture compost of dewatered sewage sludge and reed straw.

This study investigated the effectiveness of bio-augmenting aerobic cell culture to mitigate ammonia and hydrogen sulfide emission in sewage sludge composting amended with reed straw (with the weight ratio of 1:0.3-0.4). During the 20-day aerated lab-scale composting, adding 200-mL culture (56.80 NTU) reduced ammonia and hydrogen sulfide emissions by 38.00% and 54.32%, and conserved total nitrogen and sulfate by 39.42% and 70.75%, respectively. Organic matters degradation was quick started 1 day ahead. Comparing to the control, nitrate content increased 38.75% at the end of the compost. Bioaugmentation evened the distributions of bacterial communities in the thermophilic phase. The shift was mainly due to 22.97% of relative abundance of Proteobacteria depressed and 157.16% of Bacteroidetes increased, which were beneficial for nitrogen conservation and glycan breakdown, respectively. In summary, the results demonstrated that bioaugmentation addition could be an effective strategy for enhanced sludge composting.