The five discrete, but related studies presented in this thesis investigate several aspects of the physiology and biochemistry of whole animals, perfused and isolated tissues from fishes and other vertebrates. Important fundamental questions about tissue metabolism and energy supply and utilisation in relation to oxygen supply, in addition to applied questions relating to commercial harvesting and post-mortem muscle physiology were addressed. Oxyconformance of oxygen consumption (VO2) at low oxygen delivery rates was shown using an isolated, perfused salmon tail preparation, composed primarily of skeletal muscle. Addition of pig red blood cells to the perfusing solution at a haematocrit of 5 or 10%, increasing the capacitance, resulted in oxyregulation of VO2 by the tail tissues. Below c.60 ml O2.kg-1.h-1 of oxygen delivery, VO2 was delivery dependent. Above this value additional oxygen delivery did not increase VO2 of resting muscle above c.35 ml O2 kg-1.h-1. The preparation was validated by measuring mitochondrial activity using MTT and blood flow distribution to the red and white muscle using fluorescent microspheres. Evidence of both O2-independence of VO2 in the vasculature and strict O2-dependence of VO2 in striated muscles of fishes and a mammal is presented using isolated vascular tissue and an in vitro tissue slice model. VO2 by vessels from rat, salmon and hagfish showed varying degrees of independence between PO2s of 15-95 mmHg in vitro (1 mmHg = 0.133 kPa). Above and below these values, VO2 was highly PO2-dependent. VO2 by cardiac and skeletal muscles from rat, salmon, snapper and hagfish were shown to relate linearly to PO2 between zero and 125 mmHg. VO2 in these tissues was highly dependent on tissue type (cardiac, red and white muscle) which correlated with haem protein concentration. The increase in VO2 in muscle slice mitochondria uncoupled with FCCP and DNP ruled out diffusion-limitation as a constraint on VO2. Mitochondrial activity was constant over time and reoxygenation of the Ringer bathing the tissues after the initial run down in PO2 resulted in VO2 rates that were unchanged from the starting values, demonstrating that the tissues remained viable over time. ATP turnover in red muscle was significantly increased at 100 mmHg relative to 30 mmHg, and increased in both treatments from values at the start. Our data suggest that ATP supply and ATP demand were reduced in conjunction with falling PO2. The effects of hydrogen sulphide (H2S) (derived from Na2S) and isoeugenol exposure on activity, VO2 and ventilation frequency (Vf) in a teleost fish are reported. In the H2S treatment group (200 μM Na2S) both resting VO2 and Vf decreased after 30 minutes of exposure, concurrent with narcosis and a loss of equilibrium. These events corresponded with a significant fall in VO2 (33%) and Vf (20%) by 15 minutes, both declining further to a nadir of 40% of resting values at 30 minutes. After flushing, VO2 increased to resting levels, with Vf remaining significantly depressed until 30 minutes of recovery. Recovery was accompanied by regained mobility and equilibrium and significantly increased VO2 and Vf. Isoeugenol anaesthetised fish (0.011 g.L-1) reached stage 4-5 of anaesthesia accompanied by significant decreases in VO2 (45%) and Vf (25%) at 25 minutes, both parameters declining further to around 64% and 38% respectively by 35 minutes. Similar to H2S exposed fish, VO2 increased to resting values after flushing, followed by a significant rise in VO2. Likewise, Vf had risen to resting values post-flushing, subsequently increasing significantly during recovery. Overall, VO2 in relation to resting rate was reduced in the isoeugenol treated animals, while in H2S treated fish, exposure there was increased oxygen usage, possibly associated with a toxic effect. H2S significantly reduced cytochrome c oxidase activity in muscle and gill tissue in vitro between 69-79% at 20 μM and 77-97% at 200 μM Na2S, while isoeugenol had no effect on activity in any tissue. Calorimetric and biochemical profiles of anoxic, post-mortem white muscle from Chinook salmon subjected to rested and exhausted harvesting regimens at their acclimation temperature (10°C) are reported. Prior to harvest rested animals were anaesthetised with 0.012 g.L-1 isoeugenol without disturbance. The muscle of these animals had a high metabolic rate at the time of death, at around 400 μW.g-1, which declined rapidly over the first 12 hours to15 μW.g-1. Exhausted animals were forced to swim and were crowded before capture, resulting in an initial heat output of <10 μW.g-1. Heat output was significantly greater in the rested group at the time of death and for 7 hours post-mortem. In both groups there was an exothermic event, occurring between 4 and 6 hours post-mortem amounting to a rise of around 35 μW.g-1. A one-phase exponential decay model appropriately described the net heat output of the rested profile minus the exhausted data. Rested animals had significantly higher initial cut surface pH (7.5 vs 6.7), tissue glycogen (16 vs 2 μmol.g-1), creatine phosphate (18 vs 0.1 μmol.g-1), ATP (6 vs 3.5 μmol.g-1) and potential energy (30 vs 7 μmol.g-1) than the exhausted group, which had significantly elevated tissue concentrations of lactate (43 vs 18 μmol.g-1) and glucose (5 vs 2 μmol.g-1). Potential energy in the form of ATP, glycogen and creatine phosphate remained elevated for an extended period post-mortem in rested animals while catabolites further down the chain such as inosine, hypoxanthine and uric acid accumulated at similar rates in both groups. We examined the relationship between exogenous and endogenous H2S and oxygen partial pressure in isolated hagfish and lamprey vessels that exhibit profound hypoxic vasoconstriction (HVC). In myography studies, H2S (Na2S) dose-dependently constricted dorsal aortas (DA) and efferent branchial arteries but did not affect ventral aortas or afferent branchial arteries, which was similar to the effects produced by hypoxia. Sensitivity of H2S-mediated contraction in hagfish and lamprey DA was enhanced by hypoxia. HVC in hagfish DA was enhanced by the H2S precursor cysteine and inhibited by amino-oxyacetate (AOA), an inhibitor of the H2S-synthesising enzyme, cystathionine β-synthase, and unaffected by propargyl glycine, an inhibitor of cystathionine λ-lyase. Oxygen consumption (MO2) of hagfish DA was constant between a PO2 of 15 and 115•mmHg, decreased when PO2 <15•mmHg, and increased if PO2 exceeded 115•mmHg. 10 μmol.l-1 H2S increased and concentrations above 100 μmol.l-1 H2S decreased MO2. Consistent with the effects on HVC, cysteine increased and AOA and hydroxylamine, an inhibitor of pyridoxyl 5’-phosphate-dependent enzymes, decreased MO2. These data show that H2S is a monophasic vasoconstrictor of specific cyclostome vessels and because hagfish lack vascular NO, and vascular sensitivity to H2S was enhanced at low PO2, it is unlikely that H2S contractions are mediated by either an H2S-NO interaction or an oxidation product of H2S. These experiments provide additional support for the hypothesis that the metabolism of H2S is involved in oxygen sensing/signal transduction in vertebrate vascular smooth muscle. Together the findings of this thesis contribute to the understanding of oxygen utilisation and energetics in relation to oxygen supply in a number of tissues. These data further our understanding of respiratory physiology and may have practical applications in the seafood industry.

Emission of hazardous gases such as hydrogen sulphide (H2S) by a variety of industrial processes and as a result of agricultural activities has become an issue of great concern over the years. The control of these gases is needed to ensure public safety, to protect the environment, and lastly to comply with occupational and environmental regulations. Several techniques including biological and physicochemical methods have been applied to remove these gases from contaminated air streams. In this work, Zinc oxide (ZnO) nanoparticles were used to adsorb H2S gas at ambient temperatures. The effects of H2S concentration (80-1700 mg L-1), nanoparticle size (18, 80-200 nm), gas flow rate (200 and 450 mL min-1), temperature (1-41C) and adsorbent quantity (0.2-1.5 g) were investigated in the laboratory scale. A semi-pilot system was also developed and used to treat H2S emission from stored swine manure. The results show that when H2S concentration was increased the adsorption capacities (both breakthrough and equilibrium) increased and the nanoparticles reached the saturation state faster. When nanoparticles of different sizes were tested, it was observed that 80-200 nm particles got saturated with H2S faster than 18 nm particles. The adsorption capacities were higher with 18 nm particles than those with 80-200 nm. Temperatures did not have an effect on how fast the nanoparticles got saturated and on breakthrough adsorption capacity, but equilibrium adsorption capacity increased due to increase in temperature. The breakthrough and equilibrium adsorption capacities increased with increased quantity of nanoparticles. BET isotherm described the equilibrium data with higher accuracy as compared to other adsorption isotherms which were tested. Semi-pilot scale tests proved the effectiveness of 18 nm ZnO nanoparticles in capture of H2S emitted from stored swine manure. For an experimental period of approximately 100 minutes the level of H2S was reduced from an average initial value of 235.785.2 mg L-1 to a negligible level (an average value of 0.26 mg L-1) corresponding to an H2S removal of at least 99%. Semi pilot tests also showed that 18 nm ZnO nanoparticles were able to capture about 74% of NH3 that passed through the adsorption column.

O H2S é um gás que causa preocupação devido aos efeitos que pode provocar a saúde, a corrosão sobre alguns materiais e a redução do poder calorífero no aproveitamento de biogás, mesmo quando presente em baixas concentrações. O uso de biogás como fonte energética tem crescido nos últimos anos, impulsionando a remoção do sulfeto de hidrogênio, uma vez que a presença de tal gás reduz a capacidade calorífica do biogás e causa danos às instalações. Diante disso, várias técnicas são utilizadas na remoção de H2S, sendo uma delas, a adsorção. Os processos de separação por adsorção são muito utilizados para a remoção de poluentes gasosos de misturas gasosas. Neste trabalho foram realizados experimentos da adsorção do H2S sobre lodo seco, em coluna de leito fixo, para obtenção da capacidade de adsorção dinâmica do lodo e como esta seria afetada pelas variáveis de processo: concentração de alimentação e vazão de alimentação. Para tanto, foi concebida e instalada uma unidade de bancada de adsorção em leito fixo, com facilidades experimentais necessárias para testes dinâmicos, com o emprego da técnica de interpretação de curvas de efluência, um método útil para a avaliação do desempenho de um adsorvente em colunas de leito fixo. Testes preliminares mostraram que a unidade de bancada apresentou versatilidade, podendo ser operada com vazões de até 5 L/ min e concentração de H2S na mistura gasosa de até 500 ppm. Os resultados obtidos mostraram que a capacidade de adsorção do lodo seco foi muito baixa, com valores variando de 3,30 x 10-5 a 2,54 x 10-3 mg de H2S/g de lodo seco e existência de caminhos preferenciais no leito. / It is widely known that H2S is a gas which causes preoccupation due to the potential risks to health, corrosion in materials and reduction of the calorific value, even when present in low concentrations. The application of biogas as an energetic source has increased in last years, promoting the hydrogen sulphide removal, so that H2S presence can reduce the biogas energetic capacity and cause damage in the installations. Therefore, many techniques are used to H2S removal, one them is adsorption. The adsorption separation processes are widely used in the removal of pollutants gaseous from gas mixtures. In this work, experiments were performed on the adsorption of H2S the dry sludge in a fixed bed column, aiming to obtain the dynamic adsorption capacity and how this would be affected by the process variables: feed concentration and feed flow rate . For that, we designed and installed a bench unit to fixed bed adsorption with necessary experimental facilities for dynamic tests with the use of the technique of interpretation breakthrough curves, an useful method for evaluating the performance of an adsorbent columns fixed bed . Preliminary tests showed that the bench unit has presented versatility and efficiency and it can be operated at flow rates up to 5 L/min and H2S concentration in the gas mixture up to 500 ppm. The results showed that the adsorption capacity of the dried sludge was very low , with values varied from 3.30 × 10-5 to 2.54 × 10-3 mg H2S/g of dry sludge and the existence of preferential paths in the bed .

Xylem Inc. develops pumps and integrated solutions for sewages systems. A new concept has been designed to reduce the levels of hydrogen sulphide, H2S, in wastewater. H2S is a toxic, stinking gas that smells at levels above 0.002-0.2 ppm. Recommended exposure level is 15 ppm for 15 minutes. The gas is soluble in water and arises with both increasing temperatures and long retention times. Levels of H2S normally differ between 0-1000 ppm, depending on the time of year. The new concept, a pre-chamber installed upstream a pump station, is called Odomin. Inside Odomin H2S is oxidized to sulphuric acid, H2SO4, on moist surfaces. A plate is used to splash thewastewater onto the moist surfaces surrounding the plate. This master thesis aims to find the reduction rate, in terms of H2S, between Odomin 65 and the pump sump and to evaluate three factors that have possibility to improve the performance of Odomin 65. The investigated factors are 1) a sacrificial anode made from carbon steel 2) a reduced area of the inlet which increases the splash effect and 3) an increased inner area to increase themoist surfaces inside Odomin. The evaluation is made with 23 factorial design. The analysis indicates that no factor affect the daily mean value with a significance at 5%. The sacrificial anode is the one factor showing a reduction by the levels of H2S in the pump sump for both mean and extreme values. The general reduction rate is 5.33 and this can be increased with 55% by using the splash. The tests were affected by several influences that impact the trustworthiness of the results. Therefore this analysis needs additional investigations in order to be verified. / Xylem Inc. utvecklar pumpar och lösningar för avloppssystem. De har utvecklat ett nytt koncept för att reducera halten av svavelväte, H2S, i avloppsvattnet. H2S är en giftig, illaluktande gas med kännbar lukt vid 0.002-0.2 ppm. Rekommenderat är att utsättas för högst 15 ppm under 15 minuter. Gasen är löslig i vatten och nivåerna ökar med både höga temperaturer och långa uppehållstider i ledningarna. Normalt sätt kan nivåerna av H2S variera mellan 0-1000 ppm, beroende på årstid. Det nya konceptet som kallas Odomin är en för-kammare som installeras uppströms till en pumpstation. I Odomin oxideras H2S till svavelsyra, H2SO4, på våta ytor. Genom att avloppsvattnet kaskaderar på en platta kan gasen komma i kontakt med våta ytor kring plattan. Examensarbetet syftar till att hitta reduktionstalet mellan Odomin 65 och pumpsumpen samt utvärdera 3 faktorer som kan förbättra effekten av Odomin. De undersökta faktorerna är 1) en offeranod av kolstål 2) en minskad inloppsarea för att öka kaskadet och 3) en ökad inre area, för att öka andelen våta ytor, i Odomin. De 3 faktorerna utvärderas med faktorförsök (factorial design). Utvärderingen ger indikationen att ingen av de tre faktorerna påverkar det dagliga medelvärdet på en 5 % signifikansnivå. Offeranoden är den faktor som tenderar minska både medelvärdet och extremvärdet i pump sumpen. Reduktionen av H2S mellan Odomin 65 och pump sumpen är 5.33 och analysen visar att en ökad kaskadeffekt kan öka reduktionen med 55 %. Testerna influeras av flera yttre faktorer vilket påverkar resultatens trovärdighet. Denna analys bör därför repeteras för att resultaten ska kunna verifieras.

Svavelväte, H2S, är en giftig och illaluktande gas. Den karakteristika ''ruttet ägg''-lukten kan kännas redan 0.02ppm och det hygieniska gränsvärdet för exponering under en arbetsdag ligger på 5ppm, enligt arbetsmiljöverkets restriktioner. Dessutom är gasen korrosiv på betong och övrig utrustning och minskar därmed livslängden på ledningssystem. Svavelväte bildas i avloppsvatten under anaeroba förhållanden vilka typiskt uppstår i spillvattenledningar med långa uppehållstider. Syftet med detta arbetet var att kartlägga vilka åtgärder för att minska bildningen av svavelväte som användes, hur dessa har fungerat i praktiken samt försöka hitta ett samband mellan vilka åtgärder som passar i vilket typ av system. Detta gjordes med en grundläggande litteraturstudie samt datainsamling via telefon, e-mail och intervjuer. Studien visar att dosering med kemikalier var den vanligaste åtgärden följt av någon typ av luftningsanordning. Mätningar på hur svavelvätehalter påverkas i samband med dessa åtgärder var dock svåra att hitta.  Arbetet visade på en komplexitet i bildandet av svavelväte. De fysiska förutsättningarna i ledningarna såsom dimensioner, flödeshastighet, temperatur etc. påverkar också svavelvätebildingen. Förutsättningarna i ledningarna beror av många faktorer vilka ständigt varierar. Samtliga beskrivna åtgärder har enligt de kommuner där de införts och testats haft önskad effekt utifrån en subjektiv bedömning. Studien visar att grundläggande mätningar är nödvändiga för att klargöra vilka åtgärder som är mest effektiva vid givna förutsättningar. För att i framtiden kunna tackla detta antagligen växande problem i svenska ledningsnät bör alltså fler och noggrannare mätningar göras. Mätningarna bör göras både innan och efter en åtgärd sats in samt uppföljande mätning för att se om åtgärden bibehåller önskad effekt. En databas med denna typ av mätningar skulle dels gynna framtida forskning, dels hjälpa kommuner att välja rätt metod för att lösa svavelvätereleaterade problem. / Hydrogen sulphide is a toxic gas with a malodorous smell. Even in very low amounts, 0.02ppm, the rotten egg odor is noticable. The limit exposure per day is 5ppm according to The Swedish Work Environment Authority's restrictions. In addition, the gas is very corrosive to concrete and equipment, thus reducing the lifetime of wastewater collection systems. Hydrogen sulphide is formed in wastewater under anaerobic conditions, which typically occur in wastewater systems with long residence times. The aim of this study was to find which methods are used to reduce the formation of hydrogen sulphide. How these have preformed in practice and try to find a connection between which methods are suitable in which type of system. This was done with a literature study as well as data collection via telephone, e-mail and interviews.  Dosing with chemicals proved to be the most common method to reduce hydrogen sulphide, followed by some kind of ventilation devices. Measurements of hydrogen sulphide content in connection with these methods was, however, difficult to find among the contacted users.  This study showed a complexity in the formation of hydrogen sulphide since the conditions in wastewater collection systems depend on many factors which constantly varies. According to the municipalities where methods were introduced and tested, the desired effect based on a subjective assessment was reached. The study shows that measurements are necessary to clarify which methods are most effective under given conditions.  In order to deal with this possibly growing problem in Swedish waste water collection systems, more accurate data collection should be done. Both before, after and follow up data, regarding the intervention should be collected when studying this issue. Doing so would greatly benefit future research and help municipalities in solving this problem.

<p>The Athabasca oil sands produce 20% of Canada’s oil, which in turn creates trillions of cubic meters of waste. The Alberta government mandates that oil sands land be reclaimed to its natural state after mining has occurred. Syncrude Canada is currently creating a novel freshwater fen on top of a composite tailings (CT) deposit as a pilot large-scale reclamation project. CT are both microbially and sulfur rich, in addition, the fen could be a potential source of labile organics and sulfate reducing bacteria which could further stimulate sulfur cycling by microorganisms with the potential to stimulate H₂S_(g) generation, a health and safety concern. Therefore, this thesis examines three main research questions regarding this H₂S production within the Sandhill reclamation fen: 1) Is H₂S generation widespread within the porewaters of the CT and sand cap of the developing Sandhill Fen reclamation project? 2)<strong> </strong>Do microbial metabolisms capable of metabolizing Fe and S linked to H₂S generation occur within CT and sand cap of the developing Sandhill Fen? and 3) Will seasonality and ongoing fen construction impact H₂S generation?</p> <p>Field and experimental results herein discuss potential microbial and abiotic metabolisms and pathways that effect sulfur and iron cycling that could affect hydrogen sulfide generation within the composite tailings and developing fen during three seasonal sampling campaigns from June 2010 to July 2011. Results indicate that detectable H₂S_(aq) occurred in the fen porewaters during each sampling campaign, with a trend of increasing H₂S_(aq) concentrations as construction of the fen progressed. Further, enrichment results indicate that microbial sulfur and iron redox reactions are likely affecting the H₂S_(aq) generation. Experimental microcosm results indicate that the CT may contain unstable sulfur species that can contribute to H₂S_(aq) generation and sequestration in the CT as pyrite. Additionally, the evolution of the Sandhill Fen changed the microbial communities that were present <em>in situ</em> as well as shifted dominance of species type in environmental microbial enrichments. The putative function of these bacteria show a shift from autotrophy to increased heterotrophic metabolisms as the fen is being constructed, suggesting the addition of labile organic substrates from the peat and woody debris are both changing the dominant metabolisms and well as increasing microbial diversity to the underlying CT and sand cap of Sandhill Fen. Results of this thesis established widespread microbial Fe and S metabolisms within CT for the first time and indicated that fen reclamation will alter microbial activity with implications for S cycling within CT. Although this thesis covers a short sampling time frame, it is clear that H₂S_(aq) generation is an important factor to consider during large scale CT reclamation. While microorganisms are present and could be impacting Fe and S cycling, the CT materials should be investigated further in regards to their potential for H₂S_(aq) generation. More consideration should be given to inhibiting H₂S_(aq) generation or supporting FeS formation within the reclamation fen.<strong></strong></p> / Master of Science (MSc)

No description available.

As fontes hídricas disponíveis para o consumo humano vêm sendo comprometidas. Para resolver este problema, várias técnicas de detecção de contaminação fecal foram desenvolvidas. Em 1982, Manja e colegas desenvolveram método H2S que é simples, rápida e de baixo custo e detecta bactérias produtoras de H2S e, assim, a contaminação fecal. Neste trabalho foi analisada a eficácia de detecção de micro-organismos produtores de H2S frente a adição de L-cistina (125mg/L e 250mg/L) e desoxicolato de sódio (DS) (0,1% e 0,3%) e na presença de bactérias não produtoras de H2S para verificar se a presença destas bactérias interferem na detecção dos isolados H2S+. Assim, comparou-se o teste H2S com a membrana filtrante e o Colilert®. Os resultados deste estudo indicam que o meio H2S com adição de 0,3% de desoxicolato de sódio se mostrou mais rápido e sensível. Quando comparado com outras metodologias clássicas, o meio com 0,3% apresentou uma ligeira queda na sensibilidade mas o método H2S se mostrou mais sensível que o Colilert. / Water supply for human consumption have been compromised. Several detection methods for fecal contamination have been developed to solve this problem. Manja and co-workers (1982) developed a simple, fast and low-cost method for fecal contamination based on detection of sulfate-reducing bacteria, the H2S method. This work aimed to analyse the detection efficiency of the H2S method under different conditions: with L-cystine (125mg/L e 250mg/L) and sodium deoxycholate (0.1% e 0.3%). Also, non-sulfate-reducing bacteria interference were evaluated. Comparison tests were made through membrane filtration and Colilert®. Our results indicate a faster and more sensible for the 0.3% sodium deoxycholate condition. Compared to other classic methodologies, the 0.3% sodium deoxycholate condition slightly decrease the sensibility. However the H2S method was more sensitive than the Colilert one.

The cycling of biogenic volatile sulfur compounds (VSCs) within marine and terrestrial ecosystems has been shown to play an integral role in atmospheric chemistry; by influencing global climate change through the creation of cloud condensation nuclei and controlling acid-base chemistry; as well as influencing sediment chemistry including the interactions with trace metals, particularly regarding iron sulfide formation. Despite this, the examination of VSCs within Australian coastal acid sulfate soils (ASS) is an unexplored area of research. As ASS in Australia occupy an area in excess of 9 M ha, there is a clear need for a greater understanding of the cycling of these compounds within such systems. This thesis looks at the concentrations of several VSCs within agricultural and undisturbed ASS on the east coast of Australia. Initial measurements of sulfur dioxide (SO2) were made using passive diffusion samplers, which were followed by two detailed field-based studies looking at the concentrations and fluxes of both SO2 and hydrogen sulfide (H2S) using flux-gradient micrometeorological techniques. These novel results indicated that this agricultural ASS was a substantial source of atmospheric H2S (0.036-0.056 gSm-2yr-1), and SO2 (0.095-0.31 gSm-2yr-1), with flux values equating to many other salt- and freshwater marshes and swamps. The flux data also suggested that the ASS could be a continual source of H2S which is photo-oxidised during the daytime to SO2. Measurements of both compounds showed separate, inverse correlations to temperature and moisture meteorological parameters indicating possible contributing and / or causal release factors. Further identification of these and other VSCs within ASS samplers was undertaken in the laboratory using gas chromatography in combination with solid-phase microextraction. Although SO2 and H2S were not discovered within the headspace samples, two other VSCs important in atmospheric sulfur cycling and trace metal geochemistry were quantified; dimethylsulfide (DMS; &gt 300??g/L) and ethanethiol (ESH &gt 4??g/L). The measurements of H2S, DMS and ESH are the first quantifications with Australian ASS, and they may be important for refining regional or local atmospheric sulfur budgets, as well as interpreting previous SO2 emissions from ASS. Ultimately this thesis further enhances our understanding of the cycling of VSCs within acid sulfate systems.

In Lithuania the amount of waste generation is increasing every year. According to national strategy, all wastes should be disposed in new regional landfills. Landfills pollutes environment with leachate and landfill gas and odours. Landfill gas consists of odorous compounds and one of them is hydrogen sulphide (H2S). Hydrogen sulphide is highly toxic and affects the nervous system with low threshold. As the landfill gas and leachate generation was word widely investigated before this work, it is not necessary to provide new researches on them. The measurements of H2S generation were provided in Jerubaiciai landfill. For the measurements was used “site-on” measurement method, measurements were provided with equipment GD/MG 7, in 51 measurement points and 2 monitoring wells, during different seasons of the year. Results of the measurement shows, that amount of H2S varies in different areas of landfill and during different seasons. The results of dispersion modeling achieved with dispersion model AERMOD, provided under calm weather conditions and under wind dominated in that session winter speed and direction, during different seasons of the year shows, that H2S spreads from landfill in longest distances from landfill’s section during summer (almost in distance equal to 2.5 km the H2S concentration is higher then Highest Allowable Concentration ). In autumn and spring this distance is equal to 1.5 km, and in winter – 800 m. / Susidarančių komunalinių atliekų kiekis Lietuvoje kiekvienais metais didėja. Pagal nacionalinę strategiją, visos komunalinės atliekos Turi būti deponuojamos regioniniuose sąvartynuose, kurie teršia aplinka filtratu iš sąvartyno išsiskiriančiomis dujomis bei kvapais, kurių veina iš sudedamųjų dalių yra sieros vandenilis (H2S). H2S matavimai buvo atlikti Jerubaičių sąvartyne. Iš sąvartyno išsiskiriantis H2S kiekis buvo tiriamas jo išsiskyrimo vietoje, t.y. sąvartyno teritorijoje. Šis matavimo metodas buvo pasirinktas remiantis tuo, kad iš sąvartyno išsiskiriančios taršos dydis ir poveikis priklauso nuo daugelio aplinkos faktorių. Matavimai, naudojant prietaisą GD/MG 7, buvo atlikti 59 matavimo taškuose ir 2 monitoringo šuliniuose, skirtingais metų laikai. Gauti tyrimų rezultatai parodė, kad šios medžiagos kiekis yra skirtingas įvairiose sąvartyno zonose bei įvairiais metų laikais. Norint ištirti H2S sklaidą buvo atliktas skaitmeninis dispersijos modeliavimas naudojant programą AERMOD. Jo metu vienu atveju buvo pasirinktos stabilios meteorologinės sąlygos, o kitu pasirinkti dominuojančios konkrečiu metų laiku vėjo kryptys ir greičiai. Modeliavimo rezultatai parodė, kad vasarą H2S didžiausia leistina koncentracija pasiekiama tik maždaug 2,5 kilometrų, rudenį ir pavasarį 1,5 kilometrų, o žiemą - už 800 metrų atstumu nuo sąvartyno teritorijos.