Hydrogen Sulfide Gas Emissions Research Articles

A case Study of Fat and Release of Hydrogen in Sewage Sulfide During the Management of Sewage Projects

During sewage projects, management appears Hydrogen sulfide (H2S) emission-related odours have been a problem in sewage project networks for decades. One of the gases that directly harms employees and network infrastructure is hydrogen sulfide gas. Using the TOXCHEM software, the network of the Al-Hur project in Karbala, south of the Iraqi capital, Baghdad, was simulated for three main lines of different diameters 630, 315, and 1000 mm, each with a diameter of 1000 meters, they are connected to a main manhole by drop structure, and then to the lift station. Samples for these diameters were collected for two seasons (summer and winter) with all the necessary parameters of this network to be included in the model. The model was validated for the two seasons, and the results were very close to reality after being examined in a statistical way, where the results of R and RMSE were (0.821 and 0.821) and (0.000462 and 0.000184) for Summer and Winter, respectively. Sensitivity analysis studied wastewater characteristics with different levels of H2S loading rate, flow rate, suspended solid concentration, oil/grease concentration, and temperature. The results showed that all emissions in these networks are dangerous, especially in the summer when the emissions concentrations for pipe 315, pipe 630, pipe 1000, drop 315, drop 630 and the lift station were 7.6, 6.2, 2.5, 8.01, 3.78 and 6.06 ppm, respectively. By utilizing a TOXCHEM model, the study helped to understand the fate and emission of hydrogen sulfide gas in all parts of the networks.

Using TOXCHEM model for simulation the hydrogen sulfide behavior in a full-scale MBBR process

Odors emanating from treatment plants are a source of concern for those working in these plants. Hydrogen sulfide gas is the most dangerous aromatic compound for WWTP workers and plant equipment and facilities. In this study, hydrogen sulfide gas was modeled using the TOXCHEM model of the Aoun sewage treatment plant, which operates with the MBBR system. The TOXCHEM model was calibrated and validated and the results were within the R and RMSE parameters. Sensitivity analysis was studied on the most important factors affecting the emission of hydrogen sulfide gas in the Aoun sewage treatment plant. The results showed that the most important processes that obtain hydrogen sulfide gas are biodegradation, absorption, emission or volatilization. The results in winter, (12 °C), and summer (35 °C) about 6% and 8%, 18% and 17%, 72% and 65%, 0% and 0%, and 4% and 10% were fated as emitted to air, sorbed to sludge, discharged with effluent, biodegraded, and treated with odor removal system, respectively. The highest emission of hydrogen sulfide gas was observed in the preliminary stage (lift station, course and fine screen, API, and equalization tank), especially in the API basin, where it reached 1.8 ppm. Increasing temperatures, the air flow rate, decreasing the value of pH, increasing the flow and increasing the filling time in the pumping station all cause an increase in the emission of hydrogen sulfide gas. Modeling hydrogen sulfide gas by TOXCHEM model gave an excellent prediction to control the emission of hydrogen sulfide gas for decision makers in the plant.

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.

Effect of yeast culture (Saccharomyces cerevisiae) and garlic (Allium sativum) product mixture on growth performance, nutrient digestibility, faecal microflora, faecal noxious-gas emission and meat quality in finishing pigs

Context Dietary supplementation with a single feed additive or a combination of different feed additives as growth promoters has been researched extensively. However, few studies have tested the combined use of probiotics (yeast culture) and phytogenics (garlic products) in pigs. Aims The present study was conducted to evaluate the effect of supplementation of a mixture of yeast culture, garlic extract and garlic essential oil (YGM) on growth performance, nutrient digestibility, faecal microflora, faecal noxious-gas emission and meat quality in finishing pigs. Methods Two hundred [(Landrace×Yorkshire)×Duroc] finishing pigs (50.37 ± 1.89 kg) were randomly allotted into two dietary treatments on the basis of bodyweight (BW) and sex for a 10-week feeding trial. Dietary treatments consisted of a basal diet (CON) and CON containing 0.1% of YGM. The YGM was composed of 54.5% of yeast culture, 40% of garlic extract powder and 5.5% of garlic essential oil. There were 20 replicated pens per treatment, with five pigs (3 barrows and 2 gilts) per pen. Pig BW was measured at the beginning and at the end of the experiment. Feed consumption was recorded daily during the experiment, on a pen basis, to calculate average daily gain (ADG). Key results Dietary YGM supplementation resulted in a higher (P < 0.05) final BW and ADG than in the control groups. Pigs fed YGM supplementation diet led to a higher (P < 0.05) digestibility of dry matter (DM) than in CON. The emission of hydrogen sulfide gas from faeces was significantly (P < 0.05) decreased in pigs fed YGM diets; however, ammonia and total mercaptan emissions were not influenced. There were no differences in meat-quality parameters between the two treatments. Conclusions Dietary YGM supplementation exerted beneficial effects on BW and ADG and DM digestibility, reduced hydrogen sulfide gas emission, and did not have any adverse effects on meat-quality parameters that are related to consumer acceptance. Implications The study has provided a basis and insight for future research on application of a combination of yeast culture, garlic extract and garlic essential oils, as an alternative to antibiotics in finishing pig diets.

In-situ evaluation of predictive models for H2S gas emission and the performance of optimal dosage of suppressing chemicals in a laboratory-scale sewer

This in-situ analysis quantifies hydrogen sulfide gas emission from a simulated sewerage system, with varying slopes between 0.5% and 1.5%, under the dosing of certain mitigating chemicals. A portable H2S gas detector (OdaLog) was employed to record the gaseous phase concentration of hydrogen sulfide. The investigation was comprised of three interrelated phases. In the first stage, precision of four prediction models for H2S gas emission from a laboratory-synthesized wastewater was assessed. It was found that the model suggested by Lahav fitted the experimental results accurately. Second phase explorations included jar tests to obtain the optimal dosage of four hydrogen sulfide suppressing chemicals, being Mg(OH)2, NaOH, Ca(NO3)2, and FeCl2. In the third stage, the optimal dosage of chemicals was introduced into the experimental sewerage system, with the OdaLog continuously monitoring the H2S gas emission. According to a baseline (experiments with no chemical addition), it was found that NaOH and Mg(OH)2 performed very good in mitigating the release of H2S gas, while Ca(NO3)2 was not effective most probably due to the absence of biological activity. Furthermore, interpretation of OdaLog data through the optimum emission prediction model revealed that higher sewer slope led to more emission.

An assessment of geo-environmental properties for utilization of recycled gypsum in earthwork projects

This paper presents an assessment of geo-environmental properties for the incorporation of recycled gypsum, produced from gypsum waste, as an additive material in earthwork projects. In this study, the solubility of Fluorine, Boron and hexavalent Chromium and the emission of hydrogen sulfide gas refer to geo-environmental properties. To achieve this objective, the tested soil was mixed with recycled gypsum in conjunction with lime and cement in different proportions to overcome the solubility of gypsum and to reduce the solubility of harmful substances. The results of the study show that the utilization of recycled gypsum alone, as an additive material for earthwork projects, has a negative effect on the emission of hydrogen sulfide, while the addition of a solidification agent, such as cement or lime, to the recycled gypsum reduced the emission of hydrogen sulfide gas. The suggested contents and ratios for the gypsum–cement and gypsum–lime admixtures used in this study are safe against the emission of hydrogen sulfide because their measurements were found to be below the standard limits. Increasing the proportion of cement or lime in a gypsum–soil mixture has a significant effect on the reduction in Fluorine solubility. The content of the admixture has a significant effect on the reduction in Fluorine solubility in the case of gypsum–cement, while there is not much difference in the measured values of Fluorine in the gypsum–lime admixture. The intensity of ettringite increases with the increase in admixture content and the decrease in the admixture ratio, while the intensity of calcite increases with increases in both the content and the ratio of the admixture. The formation of ettringite has a significant effect on the capture of Fluorine, namely, the solubility of Fluorine decreases with the increase in ettringite intensity. The measured values for the solubility of harmful substances, including Fluorine, Boron and hexavalent Chromium and the emission of hydrogen sulfide gas, were found to lie within the standards for the investigated limits of the gypsum–soil mixture treated with cement or lime in the present study. This proves that the utilization of recycled gypsum in conjunction with cement or lime, as a stabilizer material and within the investigated limits, is safe and meets the environmental standards.

Hydrogen Sulfide Gas Emissions during Disturbance and Removal of Stored Spent Mushroom Compost

Spent mushroom compost (SMC) is a by-product of the mushroom industry that is used as an agricultural fertilizer. In Europe, SMC storage and use are governed by EU Nitrates Directive 91/676/EEC to protect waterways against pollution by nitrates. A health and safety risk was identified during the removal of stored SMC for land application, as the stored SMC released high levels of toxic H2S gas into the atmosphere when disturbed. In this study, emissions of H2S were monitored at two outdoor and two indoor locations where stored SMC was being removed for land application. A repeating peak-trough pattern of H2S emissions was detected at all sites, with peaks corresponding to periods of active disturbance of SMC. The highest H2S concentrations (10 s average) detected at the SMC face were, respectively, 680 and 2083 ppm at outdoor sites 1 and 2, and 687 and 89 ppm at indoor sites 3 and 4. Higher concentrations of H2S were released from older SMC compared to newer material. Indoor-stored SMC had lower moisture content (53% to 65%) compared to outdoor-stored material (66% to 72%), while the temperature of indoor-stored SMC was higher (33 degrees C to 51 degrees C) compared to outdoor-stored material (24 degrees C to 36 degreees C). The current short-term exposure limit (STEL) of 10 ppm was exceeded at all sites except site 4, which was smaller than the other sites, indicating a significant health and safety risk associated with working in the vicinity of stored SMC when it is being actively disturbed. Results suggest that SMC stored under cover in small heaps (600 m3) emits less H2S during disturbance and removal compared to SMC stored outdoors in large heaps (> 1500 m3). This should be taken into consideration in the design, construction, and management of SMC storage facilities. Health and safety protocols should be in place at SMC storage facilities to cover the risks of exposure to toxic H2S gas during disturbance of stored SMC.

Hydrogen Sulfide Gas Emissions in the Human- Occupied Zone during Disturbance and Removal of Stored Spent Mushroom Compost

Hydrogen sulfide (H2S) gas levels were monitored in the human-occupied zone at four spent mushroom compost (SMC) storage sites during removal of SMC for application on agricultural land. During SMC removal operations, H2S gas monitors were mounted on the outside of the tractor positioned at the SMC periphery, and worn by individual tractor drivers. The highest H2S concentrations (10 s average) detected outside the tractor, at the SMC periphery, and for the tractor driver were, respectively, 454, 249, and 100 ppm for the outdoor sites and 214, 75, and 51 ppm for the indoor sites. The highest short-term exposure values (STEV over a 15 min period) outside the tractor at the SMC periphery, and for the tractor driver were 147, 55, and 86 ppm for the outdoor sites and 19, 9, and 10 ppm for the indoor sites. The values exceeded the current maximum permissible concentration limit of 10 ppm for all the sites except for the SMC periphery and tractor driver at the indoor sites. Results suggest that H2S levels detected at indoor storage sites during SMC removal are lower compared to outdoor storage sites. Results indicate that there is a substantial health and safety risk associated with working in the vicinity of stored SMC when it is being disturbed and removed for land application, and that the risk is great for the tractor driver. This article discusses possible control measures and lists recommendations to reduce the risks.

Hydrogen sulfide gas emission under turbulent conditions – an experimental approach for free-fall drops

Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed.

은 나노 콜로이드를 이용한 돼지분뇨의 악취 저감 효과

The effect of SNC(silver nano colloid) on the emission reduction of odors such as ammonia (), hydrogen sulfide (), and methane () from swine excreta was studied. Silver has been used as an universal antibiotic substance and can reduce the emission of some gases by sterilizing action. Therefore, an apparatus which produces SNC was developed and was conducted its performance test. Also, the SNC made by the apparatus was applied to swine excreta sampled from a piggery in oder to find the effect on the reduction of odor emission. An electrolysis apparatus was developed to produce SNC and its capacity was 0.024 ppm/. The effects of SNC on the reduction of odor emission from swine excreta were tested for bad smell gases of ammonia (), hydrogen sulfide () and methane (). For ammonia gas, factorial experiments were conducted to find the effects of concentration and application rate of SNC. The test results for the different concentrations of 20 ppm, 50 ppm, and 100 ppm showed that the more concentration of SNC was increased, the more emission reduction of ammonia gas increased. From the test results about the effect of application rate, the more SNC was applied, the more emission reduction of increased. In order to reduce the concentration of below 5 ppm, SNC of 50 ppm is recommended to be applied at an interval of 6 hours, and is mixed with swine excreta in the volumetric ratio of 4:1. For hydrogen sulfide gas, the concentration was decreased as time went by and was reduced rapidly in the first stage of the tests for all applied concentrations of SNC (20 ppm, 50 ppm, and 100 ppm). Especially, when 100 ml of SNC with 100 ppm was applied, emission of hydrogen sulfide gas was reduced rapidly during early 4 hours after the application of SNC. And, concentration of hydrogen sulfide gas was maintained below 20 ppm after 12 hours. For methane gas, t-test showed that there was no significance on the effect of its application for all applied concentrations of SNC. Therefore, it was concluded that the application of SNC on swine excreta had no effect on the emission reduction of .

Aerobic and Anaerobic Transformations of Sulfide in a Sewer System – Field Study and Model Simulations

The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation during approximately 4 hours of anaerobic transport in the force main was significant. The following gravity sewer was aerobic and a fast reduction of the sulfide concentration was observed due to sulfide oxidation and emission of hydrogen sulfide gas to the sewer atmosphere. During 14 minutes of transport in the gravity sewer, the sulfide concentration decreased on average 30%. Despite the continuous emission of hydrogen sulfide, the concentration in the atmosphere of the gravity sewer was generally below 3% of the concentration in equilibrium with the sulfide concentration in the wastewater. This observation demonstrated that removal of hydrogen sulfide gas by adsorption onto the sewer walls exposed to the sewer atmosphere was fast compared with emission from the wastewater. An application of a conceptual sewer process model for simulating the formation and fate of sulfide in wastewater collection systems was demonstrated. The model was able to reproduce the average conditions in the investigated intercepting sewer satisfactory, but could not account for the observed variability. Overall, the model predicted that approximately 90% of the decrease of the sulfide concentration in the gravity sewer was due to sulfide oxidation and that only a small fraction entered the sewer atmosphere, causing odor and corrosion. Even so, the model predicted concrete corrosion rates of up to 1.2 mm per year in the gravity sewer section.

Glycine betaine 첨가가 돼지의 생산성에 미치는 영향

This study was conducted to investigate the effect of the addition of glycine betaine to the diet on growth performance in pigs. A total of 400 pigs were divided into 4 feeding stages(Growing I: 23.10 <TEX>$\pm$</TEX> 1.43, Growing II: 37.69<TEX>$\pm$</TEX> 1.62, Finishing I: 66.51 <TEX>$\pm$</TEX>3.44 and Finishing II: 90.42<TEX>$\pm$</TEX> 2.17 kg of initial body weight) then each feeding stage was divided into 4 treatment groups(Control: 0 0/0, Tl : 0.2 0/0, T2: 0.4% and T3 : 0.6 % of glycine betaine, respectively). The average daily gain and feed efficiency of T2 and T3 were significantly increased(p< 0.05) by dietary glycine betaine in stage I, 2 and 3. This result indicates that dietary glycine betaine could influence the pig growth performance. In feeding stage 4, the average daily gain and feed efficiency were significantly increased in 0.4% glycine betaine feeding group compared with other dietary groups(p < 0.05). Results suggest that feeding the pigs 0.4 % glycine betaine could be the most efficient dietary level. Crude protein, ether extract and crude ash digestibilities of 0.4% glycine betaine fed group were significantly increased compared with those of control group(p < 0.05). However, no significant difference was found in nutrient digestibilities among glycine betaine fed groups. Apparent faecal amino acid digestibilities of 0.4% glycine betaine fed group were more significantly higher than that of control group. The 0.4% glycine betaine fed group was significantly increased in apparent faecal amino acid digestibility compared with those of other glycine betaine fed group. No significant difference was shown in amount of microflora population between control and glycine betaine fed groups. Ammonia and hydrogen sulfide gas emission were significantly decreased in 0.4% glycine betaine feeding group compared with other dietary groups(p < 0.05).

Case study: Martin County, Florida “a utility's experience developing a new reverse osmosis treatment system”

After the state water management district required that Martin County, Florida, curtail use of a shallow freshwater aquifer and develop an alternative water supply, Kimley-Horn and Associates, Inc. was retained to conduct alternative water supply study and recommended reverse osmosis treatment system of a brackish water supply. Several technical and managerial issues arose including concentrate disposal permitting, public acceptance, and plant utilization. The water utility also had to resolve odor treatment of hydrogen sulfide gas emissions, as well scramble to find an alternate supplier of reverse osmosis membranes when a federal court order took the selected membrane off the market. Other utilities can benefit from Martin County's ordeals and successes during the development of this treatment system.