Hydrogen sulfide (H2S) is a colorless gas with a rotten-egg odor. Some people can smell hydrogen sulfide at very low levels, as 0.5 parts per billion (ppb) in air. Most hydrogen sulfide in the air comes from natural sources. It is produced when bacteria break down plant and animal material, often in stagnant waters with low oxygen content such as bogs and swamps. Volcanoes, hot springs and underwater thermal vents also release hydrogen sulfide. Industrial sources of hydrogen sulfide include petroleum and natural gas extraction and refining, pulp and paper manufacturing, rayon textile production, chemical manufacturing and waste disposal. Some bacteria change calcium sulfate, the major component of wallboard, into hydrogen sulfide. If construction and demolition debris contain large quantities of wallboard hydrogen sulfide can be formed. Production is greatest when the wallboard is finely crushed and when there is little oxygen, such as the debris is buried and soaked with water. Therefore, hydrogen sulfide is known as “sewer gas” because it is often produced by the decay of waste material. Hydrogen sulfide gas also can be found in groundwater, especially in wells near oil fields wells that penetrate shale or sandstone.

H2S is extremely toxic, and is corrosive to metals such as iron, zinc, copper, lead and cadmium. It reacts with water to form sulfuric acid that corrodes lead-based paint, concrete, metals and sewer lines. (See cover page, the photograph show a sewer pipe destroyed by corrosion).

This information source guide on “ Hydrogen Sulfide Gas” focuses on latest studies conducted on H2S in two main sources, groundwater and wastewater treatment plant. Information in the guide is drawn from international databases, water resources database (file 117), Enviroline (file40) and MEDLINE (file154). The information source guide is divided into three sections; (1) annotated bibliography (2) questions and answers about Hydrogen sulfide, and (3) selected Internet sites on H2S.

ANNOTATED BIBLIOGRAPHY

Hydrogen Sulfide (H2S) in Groundwater

Taste and odour removal from an urban groundwater establishment - a case study

Ortenberg, E ; Groisman, L ; Rav Acha, C

Water Science and Technology vol. 42, no. 1-2, pp. 123-128; 2000

Abstract: A deep groundwater well was established in a village near Tel-Aviv, in order to supply drinking water for its 30,000 inhabitants. Although all water characteristics were within the range permitted by the Israeli regulations, operators received complaints about a funny taste and a rotten-egg odour in the water. This was attributed to the presence of 0.38 mgL super(-1) hydrogen sulfide. Removing the odour by the usual method of aeration was impossible because of the populatedsurroundings. Therefore it was decided to examine chemical oxidants for taste and odour removal. A treatment with 8 mgL super(-1) of chlorine

successfully oxidized hydrogen sulfide but the complaints continued. This was attributed to the formation of elemental sulfur, which is converted into polysulfide that may hydrolyze to regenerate the odourous hydrogen sulfide. Treatment with 2 mgL super(-1) of chlorine dioxide successfully eliminates odour completely, but produces chlorite and chlorate which are above the permitted levels. A partial solution to this problem was found by a consequential treatment with 2 mgL super(-1) of ClO sub(2) for 10 min. followed by 1.5 mgL super(-1) of chlorine (30 min.). In this case the chlorite is reduced substantially to be within the permitted level. In addition, such treatmentregenerates some of the chlorine dioxide thereby increasing its residual. The odourous H sub(2)S can also be eliminated with 3 mgL

super(-1) of ozone. Advantages and disadvantages of the above treatments are discussed.

Microbial H sub(2) Cycling Does Not Affect delta super(2)H Values of Ground Water

Landmeyer, J E ; Chapelle, F H ; Bradley, P M

Ground Water vol. 38, no. 3, pp. 376-380, 2000

Abstract: Stable hydrogen-isotope values of ground water ( delta super(2)H) and dissolved hydrogen concentrations (H sub(2(aq))) were quantified in a petroleum-hydrocarbon contaminated aquifer to determine whether the production/consumption of H sub(2) by subsurface microorganisms affects ground water delta super(2)H values. The range of delta super(2)H observed in monitoring wells sampled (-27.8 ppt to -15.5 ppt) was best explained, however, by seasonal differences in recharge temperature as indicated using ground water delta super(18)O values, rather than isotopic exchange reactions involving the microbial cycling of H sub(2) during anaerobic petroleum-hydrocarbon biodegradation. The absence of a measurable hydrogen-isotope exchange between microbially cycled H sub(2) and ground water reflects the fact that the amount of H sub(2) available from the anaerobic decomposition of petroleum hydrocarbons is small relative to the amount of hydrogen present in water, even though milligram per liter concentrations of readily biodegradable contaminants are present at the study site.Additionally, isotopic fractionation calculations indicate that in order for H sub(2) cycling processes to affect delta super(2)H values of ground water, relatively high concentrations of H sub(2) (>0.080 M)would have to be maintained, considerably higher than the 0.2 to 26 nM present at this site and characteristic of anaerobic conditions in general. These observations suggest that the conventional approach of

using delta super(2)H and delta super(18)O values to determine recharge history is appropriate even for those ground water systems characterized by anaerobic conditions and extensive microbial H sub(2) cycling.

Distribution of sulfate and organic carbon in a prairie till setting: Natural versus industrial sources

Fennell, J ; Bentley, L R

Water Resources Research vol. 34, no. 7, pp. 1781-1794, 1998

Biodegradation of sulfolane in soil and groundwater samples from a sour gas plant site

Fedorak, P M ; Coy, D L

Dep. Biol. Sci., Univ. Alberta, Edmonton, Alberta T6G 2E9, Canada

Environmental Technology vol. 17, no. 10, pp. 1093-1102; 1996

Abstract: Sulfolane is used as a solvent in processes for the removal of Hsub(2)S from sour gas. Because of its high water-solubility, soil contamination by sulfolane quickly leads to groundwater contamination.To assess the possibility of using bioremediation to remove this

compound, samples of soils, groundwaters, and sandstone from a contaminated aquifer at a gas plant were used in laboratory studies to determine if they contained sulfolane-degrading microbial populations. Aerobic shake-flask slurry cultures were incubated at 26 degree and 8

degree C, and solid phase soil bioreactors, approximating bioventing, were incubated at 8 degree C to test sulfolane biodegradability. Each environmental sample yielded microbial populations that degraded sulfolane. Supplementation with N and P stimulated degradation. The most rapid rates of degradation in slurry cultures incubated at 26 degree C and 8 degree C were 8 and 4 mg L super(-1) d super(-1),respectively. In the soil column bioreactors supplemented with N and P, the rates of sulfolane biodegradation were between 0.5 and 0.7 mg kg super(-1) d super(-1).

Ground Water

Nelson, G L ; Munter, J A

Cold Regions Hydrology and Hydraulics. American Society of Civil Engineers, New York. 1990. p 317-348, 15 fig, 29 ref., 1990.

Abstract: Groundwater in cold regions differs from that in warm regions, not by virtue of any changes in its adherence to physical laws of groundwater flow, but by its interaction with frozen ground and freezing conditions in the surface environment. Permafrost, which underlies about 85 percent of Alaska, 50 percent of the Soviet Union and Canada, and 22 percent of China, is a confining layer that transmits only slight amounts of water. Movement of water occurs along thin films of liquid water adsorbed on soil grains, even at temperatures well below freezing. Groundwater is classified as subpermafrost or suprapermafrost, depending on whether it is below or above the permafrost. In the zone of continuous permafrost, suprapermafrost water is available seasonally but is susceptible to contamination. Subpermafrost water is expensive to develop and commonly brackish to saline, particularly in coastal environments. Therefore, large springs in limestone terrains are a major water resource in the Arctic. Taliks underlying rivers do not contain flowing groundwater, and are not a major water supply except in rivers such as the Mackenzie which flow throughout the winter. Coastal communities in the Arctic also have additional water supply problems caused by shallow salt water. In the zone of discontinuous permafrost, communities near rivers generally have no problem developing a water supply, although water commonly must be treated to remove iron, manganese, methane, and hydrogen sulfide. Base flow in streams is a poor indicator of aquifer properties because much of the winter discharge of groundwater freezes and does not contribute to base flow. The formation of icings in stream channels may cause high water table conditions in the winter, when it would not be expected. Water supply wells generally function well with moderate frost protection. Observation wells, however, require additional work to continually adjust to the frozen ground phenomenon termed 'frost jacking.' Water quality in cold regions is commonly

affected by reducing conditions, high concentrations of organics and reduced microbial activity. Permafrost can be thawed either by removing insulating vegetation or by regional or global climate warming, but the consequences on water supplies, waste disposal activities, engineered structures, and biological habitats may be significant.

Quality of the Ground Water around the Lower Reaches of the Miya River

Sugiyama, M ; Fujii, K ; Maeda, H ; Maruyama, T ; Kumada, H

Bulletin of National Research Institute of Aquaculture YKHKDU No. 15, p 29-36, 1989. 2 fig, 1 tab, 15 ref. English summary. 1989.

Abstract: Since the establishment of the Inland station (Tamaki campus) of the National Research Institute of Aquaculture in 1979, the rearing water for experimental fishes has been supplied by four artesian wells in the campus. Prior to the establishment of the campus, assessment of the quality of groundwater around the campus had been done in 1973 and 1974. The quality of the artesian well water were reassessed in March of 1987, in order to examine changes in the quality with the passage of years. The levels of ammonium nitrogen, nitrite nitrogen, hydrogen sulfide, and manganese which are toxic to fish were below the level

that is detrimental to fish health. The levels of total iron in the well water in 1987 were slightly higher than those in 1974. The increase in iron levels may be caused by rust release from pumping equipment submerged in each well. The present results indicate that, in spite of the increase in the pumped volume of groundwater around the Tamaki campus, the quality of artesian well water in the campus is almost unchanged compared with those in 1974, and that the water is suitable for fish culture. (Author 's abstract)

Distribution and Source of Barium in Ground Water , Cattaraugus Indian Reservation, Southwestern New York

Moore, R B ; Staubitz, W W

Water-Resources Investigations Report 84-4129, 1984. 17 p, 4 fig, 4 tab, 15 ref.

Abstract: High concentrations of dissolved barium have been found in ground water from bedrock wells on the Seneca Nation of Indians Reservation on Cattaraugus Creek in southwestern New York.Concentrations in 1982 were as high as 23.0 milligrams per liter , the

highest found reported from any natural ground-water system in the world. The highest concentrations are in a bedrock aquifer and in small lenses of saturated gravel between bedrock and the overlying till. The bedrock aquifer is partly confined by silt, clay, and till. The high barium concentrations are attributed to dissolution of the mineral barite (BaSO4), which is present in the bedrock and possibly in overlying silt, clay, or till. The dissolution of barite seems to be controlled by action of sulfate-reducing bacteria, which alter the BaSO4 equilibrium by removing sulfate ions and permitting additional barite to dissolve. Ground water from the surficial, unconsolidated deposits and surface water in streams contain little or no barium. Because barium is chemically similar to calcium, it probably could be removed by cation exchange or treatments similar to those used for water softening.

Ground - Water Geochemistry: Arsenic in Landfills

Hounslow, A W

Ground Water Vol 18, No 4, p 331-333, July/August, 1980. 1 Fig, 10 Ref. 1980

Abstract: Arsenic leaking from landfills commonly exists in +3 (arsenite) and +5 (arsenate) valence states, depending on the oxidation-reduction state of the groundwater and the presence of iron. Arsenite ion is 60 times as toxic to humans as arsenate ion. Three types of aqueous environments may be described: aerobic--dissolved oxygen present, hydrogen sulfide absent, unsaturated zone present, arsenate soluble, ferric hydroxide insoluble, arsenate adsorbed anaerobic--dissolved oxygen absent , hydrogen sulfide absent, mildly reducing, shallow groundwater, arsenite soluble ferrous iron soluble anaerobic--dissolved oxygen absent, hydrogen sulfide present, deeper groundwater, arsenic sulfides insoluble, heavy metal sulfarsenites insoluble, iron sulfide insoluble, coprecipitated arsenic sulfides. The most likely environmental pollution source is the mildly reducing anaerobic water, in which iron and toxic arsenite are most prevalent and most mobile.

Chemical Quality of Ground Water on Cape Cod, Massachusetts

Frimpter, M H ; Gay, F B

Geological Survey Water-Resources Investigations 79-65 (open-file report) 1979. 11 p, 6 Fig, 2 Plates, 2 Tab, 9 Ref.1979

Abstract: Cape Cod is a 440 square mile hook-shaped peninsula, which extends 40 miles into the Atlantic. Freshwater in Pleistocene sand and gravel deposits is the source of supply for nearly 100 municipal and thousands of private domestic wells. Most ground water on Cape Cod is of good chemical quality for drinking and other uses. It is characteristically low in dissolved solids and is soft. In 90 percent of the samples analyzed, dissolved solids were less than 100 mg/l(milligrams per liter) and pH was less than 7.0. Highway deicing salt, sea-water flooding due to storms, and saltwater intrusion due to ground-water withdrawal are sources of sodium chloride contamination.Chloride concentrations have increased from 20 to 140 mg/l, owing to saltwater intrusion at Provincetown 's wells in Truro. In Yarmouth, contaminated ground water near a salt-storage area contained as much as 1,800 mg/l chloride. Heavy metals, insecticides, and herbicides were not found at concentrations above the U.S. Environmental Protection Agency 's recommended limits for public drinking-water supplies, but iron and manganese in some samples exceeded those limits. Ninety percent of 84 samples analyzed for nitrate reported as nitrogencontained less than 1.3 mg/l and 80 percent contained 0.5 mg/l or less of nitrate as nitrogen. Water containing nitrogen in excess of 0.5 mg/l has probably been affected by municipal or domestic sewage or fertilizer, and water with less than this amount may have been affected by them.

Obstacles to Geothermal Development

Budiansky, S P

Environmental Science and Technology Vol 14, No 3, p 255-257, March, 1980. 1 Fig.

Abstract: Legal, financial, and environmental problems associated withgeothermal development are minor compared with problems associated with the development of other energy resources. However, these problems must be solved if delays are to be avoided. Direct use of geothermal energy, unlike high-temperature applications, does not cause air pollution but can result in water pollution. The use of injection wells can minimize ground water pollution, water table lowering and land subsidence. The deterioration of ground water quality surrounding an injection well over a 30 year period has been simulated by researchers at EG and GIdaho. Direct use applications are also faced with laws and regulations which were based on the concept of high-temperature,electric-generating, and revenue producing resources. These laws do not apply to low-temperature resources. With some modification, existing water law can provide the basis for direct use development. For example, geoheating would be classified as ' reasonable use ' of water resources, and appropriate rights over the entire volume of the resource should not be required for closed systems which return the water they use.

The Effect of Organic Carbon on the Concentrations of Iron and Hydrogen Sulfide in Ground Water

Stoufer, R N

1975

NOTES: Available from the National Technical Information Service, Springfield VA 22161 as PB-291 555, Price codes: A05 in paper copy, A01 in microfiche. M. A. thesis December 1975. 85 p, 18 fig, 10 tab, 54 ref, append. OWRT B-077-MO(3), 14-31-0001-3608.

Abstract: Twenty water supply wells in northern Missouri were sampled to determine the relationships between dissolved organic carbon and microorganisms on iron and sulfide concentrations in unpolluted ground water. The concentrations of ferrous iron, sulfide, organic carbon, major ions and the pH and Eh were determined on each water sample. Organic carbon and dissolved ferrous iron were readily measurable in samples. Organic carbon was generally present at low levels (2 mg/l). Even though thee was no evidence of coliform or streptococcus microorganisms none of the water samples was sterile. Two to six generaof non-pathogenic bacteria were present in each sample, the majority being nitrate reducers. Sulfate-reducing bacteria were detected in half of the samples. The data suggest that there is a poor correlationbetween the redox potential and dissolved organic carbon in ground water. The organic carbon content of the rocks appears to be a more important factor in controlling the redox potential of ground water.The data for nitrate-ammonia and sulfate-sulfide indicate that many ofthe water samples were not in internal equilibrium with respect to oxidation-reduction reactions.

Ground Water Resources of the Bedrock Aquifers of the Denver Basin Colorado

Romero, J C

1976. p 109 12 plates, 28 fig, 7 tab, 66 ref, 2 append.

Abstract: The bedrock aquifers of the Denver Basin contain vast quantities of groundwater suitable, in most localities, for all beneficial purposes. The major problems which will confront both administrators and users of this groundwater include those associated with declining water levels and deterioration of water quality. Areas in which current water level declines are rapid enough to cause concern are the South Platte River corridor, the Strasburg-Byers-Deer Trail area, and parts of metropolitan Denver. Water quality problems of the Denver Basin 's bedrock aquifers are confined predominantly to the Laramie Formation and Laramie-Fox Hill aquifer. Water from these units is locally known to contain troublesome amounts of hydrogen sulfide, methane, iron, floride and sodium. Many of these problems can probably be eliminated by avoiding multi-aquifer completions, particularly in the case of mixing Laramie-Fox Hill aquifer water with Dawson Group water. Successful management of the Denver Basin bedrock aquifers will require the collection and utilization of additional data. The importance of additional electric logs, geologic sample logs and aquifer test data cannot be over-emphasized. Also of major importance are water quality testing, an observation well network and accurate measurements of water withdrawn from the aquifer. If managed with caution, the basin can supply the water needs of several generations.

Ground Water Supplies Of Northeastern Illinois -- Quality Problems With Well Waters

Larson, T E

Journal American Water Works Association, VOL 56, NO 2, P 169-172, February 1964.

Abstract: most problems in well water quality are inherent and not Receptive to correction by any means other than external treatment.These problems are usually related to the natural hardness or iron Content of the water from the aquifer or from one of the contributing Aquifers. Perhaps the most annoying problems are due to the iron Content of the water. At times the occurrence of such problems is Inexcusable or may be condoned only because of lack of information or Adequate interpretation of information. Another less frequently Encountered but more objectionable problem is that of hydrogen sulfide In well waters. This 'rotten-egg' odor almost always demands treatment. Case studies of these problems, their causes and corrective measures taken in 3 aquifers are presented. It is concluded that in many cases the pollutants enter the well from outside the producing zone due to improper or nonexistent sealing however, it should be remembered that preventive measures taken during construction are usually superior to and less costly than corrective measures.

Gas in Ground Water

Journal of the American Water Works Association, Vol 61, No 8, P 413-414, August, 1969.

Abstract: a summary of gas characteristics in ground water is given in order to acquaint water utilities employees and others with its nature, origins, and hazards. both methane and hydrogen sulfide are commonflammable gases found in ground water, the latter being less dangerous because it has a distinctive odor. Examples of isolated explosions attributed to gas in ground water occurring in Michigan and New York State, as well as a possible one in Louisiana, are mentioned. The inimum concentration of methane in water sufficient to produce an explosive methane-air mixture (5-15 per cent methane in a gas-air mixture) above

the water from which it evolves can be as little as 1.1 ppm at normal conditions, in poorly ventilated air spaces. Under these conditions explosions can occur in shower stalls, water treatment plants, storage reservoirs, water tanks, and other poorly ventilated air spaces. Suffocation is another hazard of gas in ground waters. Safety measures for decreasing the hazards include aeration of the water before use, and adequate ventilation of air spaces around the well in places where the water is to be used.

Spectrophotometric Microdetermination of Sulfate

Davis, j b ; lindstrom, f

Analytical chemistry, vol. 44, no. 3, p 524-532, March 1972. 11 fig, 1 Tab, 22 ref.

Abstract: sulfate reduction to hydrogen sulfide is the basis for the Spectrophotometric method which has been developed for the selective Determination of sulfate in the 0-10 and 0-100 microgram (ppm in water) Ranges. Aqueous sampl Es are treated with a mixture of hydriodic acid, Acetic anhydride, and sodium hypophosphite and heated in a modified Countercurrent reaction apparatus to evolve hydrogen sulfide. The gas Is swept by nitrogen into a buffered solution of a ferric Ion and 1,10-phenanthroline, where it reduces the ferric ion to the ferrous Ion. A bright orange tris (1,10-phenanthroline - iron ii) complex forms And is measured spectrophotometrically at 510 nm. Over twenty common Ions and three sulfonated surfactants were tested to determineInterference. Only nitrite and those ions capable of yielding hydrogen Sulfide under the same conditions interfered while the sulfonated Surfactants did not interfere.

Ground water for planning in northwest Ohio, a study of the carbonate Rock aquifers

Ohio Dept. Of Natural Resources, Columbus. Div. Of Water 1970. 123 P, 73 Fig, 10 Tab, 30 Ref.

Abstract: the northwest Ohio water development plan, prepared by the Ohio water commission (1967), recommended a drilling and testing program to evaluate the quantity and quality of the ground water available in the northwest Ohio area. seventy-six large diameter limestone and dolomite wells were drilled, tested, and analyzed as the basis for this two and one-half year study. the limestone-dolomite aquifer in northwest Ohio currently yields 32.69 million gallons per day to municipal andindustrial wells. large additional quantities are pumped for irrigation and domestic supplies. estimates of well-field capacities in various undeveloped areas have been included in this report as a guide for potential development. the quality of the ground water is equally as important as quantity in planning for future use. softening is recommended for ground-water supplies throughout the study area. hydrogen sulfide is often present in varying amounts. however, in nearly all instances, objectionable concentrations of hydrogen sulfidecan be removed by simple and inexpensive processes. ground-water development in some portions of the area would be restricted by quality considerations, with present treatment methods. even considering the quality limitations, the potential of the carbonate aquifer in northwest ohio far exceeds the present ground-water development.

Hydrogen Sulfide in Wastewater

Removal of H2S by Metal Ferrites Produced in the Purification of Metal-Bearing Waste Water . Study of the Reaction Mechanism

Barrado, E ; Prieto, F ; Lozano, B ; Arenas, F J ; Medina, J

Water, Air, and Soil Pollution vol. 131, no. 1-4, pp. 367-381, 2001

Abstract: Waste water polluted with heavy metals can be successfully purified by precipitation of the metals from an alkaline solution containing iron (II), giving rise to a ferrite sludge. The solid metal ferrites obtained in this manner can be used to remove hydrogen sulphide from a gas stream. Based on a Taguchi experimental design,ferrite solid particle and pore size, and the temperature resulting in maximum retention of H sub(2)S by the solid were optimised. Under the optimum conditions, predicted by the method, each gram of ferrite was able to retain 0.274 g H sub(2)S. In addition, a ferrite containing a known lead concentration, obtained by the precipitation method underoptimal conditions of pH, temperature and Fe/Pb ratio, was used to study the exothermic H sub(2)S retention reaction. The chemical reaction occurring between the ferrite and the H sub(2)S was investigated by characterisation of the compounds before (Pb sub(0.04)Fe super(II) sub(0.96) Fe super(III) sub(2)O sub(4).nH sub(2)O solids composed of Pb sub(x)Fe sub(3-x)O sub(4), magnetite Fe sub(3)O sub(4) and hydrated lead oxide PbO sub(n).H sub(2)O) and after (PbS, PbSO sub(4), S, FeS sub(2) and alpha -FeO(OH)) the retention process.

Biological prevention and removal of hydrogen sulphide in sludge at Lillehammer Wastewater Treatment Plant

Einarsen, A M ; Aesoey, A ; Rasmussen, A I ; Bungum, S ; Sveberg, M

Water Science and Technology vol. 41, no. 6 183 pp 2000

ABSTRACT: Formation of H sub(2)S and other odorous compounds in sludge can be prevented efficiently by controlled dosage of nitrate. Lillehammer WWTP (N) had problems with malodour that originated mainly from the sludge treatment. High levels of H sub(2)S caused poor working conditions, and resulted in an overloaded hypochlorite scrubber. In addition, neighbours were complaining. Controlled dosing was necessary to avoid increased loads on the nitrogen removal process and floating sludge in the thickener, and to keep the H sub(2)S concentration and chemical costs low. This resulted in considerably better working environment and eliminated complaints from neighbours. A cost-benefit for Nutriox registered Septicity Control has been performed.

The ability of selected chemicals for suppressing odour development in rising mains

Hobson, J ; Yang, G

Water Science and Technology vol. 41, no. 6 183 pp. 2000

Abstract: The use of Nutriox registered and ferric chloride to suppress hydrogen sulphide and odour generation in rising mains is evaluatd in a pilot scale study. Without chemical dosing the hydrogen sulphide built up to the commonly predicted levels after six months. Thereafter, addition of both Nutriox registered and ferric chloride to sewage entering the rising main totally suppressed the formation of H sub(2)S. Nutriox also nearly totally suppressed the odour measured olfactometrically. The use of ferric salt at near stoichiometric levels effectively removed dissolved sulphide. Odour removal was generally good though on occasions reduction of dissolved sulphide levels to below 0.1 mg/l was not guaranteed to be accompanied by near total suppression of odour generation. The use of ferric ions at stoichiometric levels, after H sub(2)S and odours have formed in the rising main, also eliminated the dissolved sulphide. When used in this way, a significant residual odour potential, 110,000 ou/m super(3) remained in the sewage. The simultaneous reductions of odour and hydrogen sulphide observed in this study implied an apparent threshold odour concentration of 0.1 ppb for H sub(2)S, significantly lower than most values quoted in the literature.

Bioscrubbing, an effective and economic solution to odour control at wastewater treatment plants

Hansen, N G ; Rindel, K

Water Science and Technology vol. 41, no. 6 183 pp; 2000

Abstract: Based on odour nuisances from the Damhusaaen Wastewater Treatment Plant in Copenhagen, it was decided that the critical sections of the inlet structure to the treatment plant should be covered and enclosed. The ventilation air, 6000 m super(3)/h, is cleaned in a bioscrubber process. These installations have reduced the odour in the surroundings of the treatment plant to the extent that it is no longer noticeable. A cleaning efficiency for hydrogen sulphide of >99% and low residual emissions, <0.1 mg/m super(3) of organic sulphur compounds, are obtained in the bioscrubber. The consumption of the sodium hydroxide for neutralising the sulphuric acid formed is stoichiometric in relation to the amount of sulphur compounds removed. This results in relatively low operating costs corresponding to half toone fourth of the operating costs of a chemical scrubber at normal influent concentrations. In addition, the bioscrubber has proven reliable with only little maintenance and low space requirements. A bioscrubber can thus be considered an environment-friendly and competitive alternative to chemical scrubbers and biofilters.

A bioscrubber for hydrogen sulphide removal

Koe, L C C ; Yang, F

Water Science And Technology vol. 41, no. 6 183 pp, 2000

Abstract: A study was carried out to investigate the feasibility of using treated wastewater effluent to support the operation of a fixed-film bioscrubber for odorous H sub(2)S removal. A laboratory scale fixed-film bioscrubber was set up using bacteria of the genus Thiobacillus. The bacteria were isolated from a sample of municipal sludge, cultured in the laboratory and immobilised onto the scrubber's plastic packing media by an immersion method. Series of experimental runs were carried out to determine the optimal operational conditions for the bioscrubber. Results indicated that for the gas retention times equal to or exceeding five seconds, and with a H sub(2)S loading rate below 90 g-H sub(2)S/m super(3)-hr, the bioscrubber could remove H sub(2)S and odour with efficiencies greater than 99%. The behaviour of the bio-scrubber under various operation scenarios are presented and discussed in this paper.

Hydrogen Sulphide Dispersion Modelling - Urban And Rural Case Studies

Parsons, S A ; Smith, N ; Gostelow, P ; Wishart, J

Water Science And Technology vol. 41, no. 6 183 pp, 2000

Abstract: Sewage treatment works are subject to a range of parameters governing the quality of effluent and sludge produced. An additional product from treatment plants is odorous air. The causes, source, formation and measurement of odour are widely reported and reasonably

understood. An important factor in the design and management of works is the prediction of such odours. The importance of this work is explained by the possibility of future legislation controlling odour at wastewater plants. Odour dispersion modelling involves the on-site measurement or prediction of the emission rate of an odorous compound, often hydrogen sulphide, and the subsequent prediction of the atmospheric concentrations of that compound downwind of the source. This paper used the USEPA models SCREEN3 and ISCST to determine hydrogen sulphide contour concentrations emitted from unit processes at two different sewage treatment works in the United Kingdom. Results indicated that the first site, located in an urban catchment, emitted hydrogen sulphide at varying rates. The predicted downwind concentrations using "urban" dispersion coefficients correlated well with measured concentrations. At the second site, emission rates were less variable. Results from the second site produced the best correlation using "rural" dispersion coefficients. Results from both sites suggest that the definition of the surrounding land use is critical in predicting odour dispersion. The problem of determining land use is highlighted and the importance of correct meteorology is stressed. Both sites were predicted to be capable of producing hydrogen sulphide concentrations at a detectable level outside the site boundary. Odour complaints were therefore anticipated. The operational performance of a unit treatment operation is proposed as a major influence on hydrogen sulphide emission. The idea of a large database of expected emission rates from individual unit treatment processes is proposed as an input for dispersion modelling and as an aid to future design.

A review of the odour impact component of the Tasman pulp and paper air discharge permit

Vaczi, S

Ogilvie, D (ed )

ISBN: 1-877134-11-2

314 pp; 1997

Abstract: The investigation into the environmental impacts of Tasman's odorous emissions, including an assessment of mitigation options, cost the company close to $1.5 million and three years' work. An extensive monitoring system was installed to supply meteorological data, and olfactometry was used to measure the odorous emissions from the mill. This combined information provided the necessary inputs to enable dispersion modelling to be performed successfully. The work resulted in very good agreement between model predictions and ambient TRS monitors. Community annoyance levels were predicted for different mitigation options using the dispersion model concentration predictions and the dose-effect relationship between annoyance levels and the 99.5% odour concentrations. The validity of this method was verified by a community survey of odour annoyance. It was found that hydrogen sulphide is not contributing to the perceived intensity of the mill odour and the meteorology of the region plays a dominant role at triggering odour complaints. A steam stripper was installed to remove odorous compounds and methanol from a dominant odorous discharge to the aerated lagoon treatment system.

Biotechnological treatment of sulfate-rich wastewaters

Lens, P N L ; Visser, A ; Janssen, A J H ; Pol, L W H ; Lettinga, G

Critical Reviews In Environmental Science And Technology vol. 28, no. 1, pp. 41-88

1998

Abstract: Sulfate-rich wastewaters are generated by many industrial processes that use sulfuric acid or sulfate-rich feed stocks (e.g., fermentation or sea food processing industry). Also, the use of reduced sulfur compounds in industry, that is, sulfide (tanneries, kraft pulping), sulfite (sulfite pulping), or thiosulfate (pulp bleaching, fixing of photographs), contaminates wastewaters with sulfate. A major problem for the biological treatment of sulfate-rich wastewaters is the production of H sub(2)S. Gaseous and dissolved sulfides cause physical(corrosion, odor, increased effluent COD) or biological (toxicity) constraints that may lead to process failure. H sub(2)S is generated by sulfate-reducing bacteria, in both anaerobic and aerobic (anoxic microenvironments) wastewater treatment systems. No practical methods

exist to prevent sulfate reduction. Selective inhibition of SRB by molybdate, transition elements, or antibiotics is unsuccessful at full scale. Selection of a treatment strategy for a sulfate-rich wastewater depends on the aim of the treatment. This can be (1) removal of organic matter, (2) removal of sulfate, or (3) removal of both. Theoretically, wastewaters with a COD/sulfate ratio of 0.67 or higher contain enough COD (electron donor) to remove all sulfate by sulfate-reducing bacteria. If the ratio is lower, addition of extra COD, for example, as ethanol or synthesis gas (a mixture of H sub(2), CO sub(2), and CO) is required. Complete COD removal in wastewaters with a COD/sulfate ratio of above 0.67 also requires

methanogenic COD degradation. Methods to reduce sulfide toxicity and to allow optimal COD removal are presented. Sulfate can be removed from the wastestream by the coupling of asulfide oxidation step to the sulfate reduction step. Sulfur can be recovered from the wastewater in case H sub(2)S is partially oxidizedto insoluble elemental sulfur.

Effect of distillery effluent on the dissolved organic matter, hydrogen sulfide and salinity of channel water

Boominathan, R ; Khan, S M M N

environment and ecology vol. 13, no. 1, pp. 52-55, 1995

Abstract: The present study deals with the level and effect of dissolved organic matter, hydrogen sulfide and salinity in Uyyakondan channel water before and after the dissolution of distillery effluent from nearby distillery. The three parameters obviously increased after the

entry of effluent which put adverse effects on the ecosystem.

Evaluation of chemicals to control the generation of malodorous hydrogen sulfide in waste water

Tomar, M ; Abdullah, T H A

Water Research vol. 28, no. 12, pp. 2545-2552, 1994

Abstract: The effect of hydrogen peroxide, sodium/calcium hypochlorite and ferrous/ferric salts on hydrogen sulfide dissolved in waste water were investigated to establish an effective odour control system for Kuwait Sewage Networks. The waste water samples were collected from the inlet structure of main pumping station with pressure pipelines and analyzed for dissolved sulfide and pH before and after addition of chemicals individually and in combination under controlled laboratory conditions. The waste water contained dissolved sulfide in the range of 18 to 25 mg/l and pH ranged between 7.2 and 7.8. Various concentrations of above mentioned chemicals were tried to determine the accurate chemical

requirement for oxidation or precipitation of dissolved sulfide in waste water. The reaction temperature was maintained at 35 degree C ( plus or minus 2 degree C), the normal temperature of waste water in Kuwait during summer. To oxidize 1 g of sulfide 1.25, 2.0 and 1.8 g hydrogen peroxide, sodium hypochlorite and calcium hypochlorite were required respectively. To remove 1 g of sulfide by precipitation with ferrous sulfate and ferric salt solution, 8 g and 4 g ferrous and ferric salt were required respectively under laboratory investigations. A combination of sodium hydroxide and sodium hypochlorite was also studied to control malodorous hydrogen sulfide in waste water. The addition of sodium hydroxide with sodium hypochlorite in waste water reduced the demand of hypochlorite 50%. This procedure was found to be cost effective and best suited for the warm climate of Kuwait and was implemented in the field at a screw conveyor type lifting station with gravity sewer pipelines. When sodium hypochlorite was injected withoutshock loadings of sodium hydroxide 46% reduction of dissolved sulfides was recorded and it was increased to 57% with shock loadings of sodium hydroxide, though the quantity of sodium hypochlorite was reduced to half than the former case. Similarly, 45 and 70% reduction in the emission of gaseous hydrogen sulfide was recorded with NaOCl injection without and with NaOH shock loading respectively. The cost comparison of all the chemicals when applied in field is also presented.

Large Scale Anaerobic-Aerobic Treatment of Complex Industrial WasteWater Using Biofilm Reactors

van Leeuwen, H L J M ; Hols, J ; Weltevrede, R ; Mulder, A ; Heijnen, J J Gist-brocades

Water Science and Technology WSTED4, Vol. 23, No. 7/9, p 1427-1436, 1991.

Abstract: Warm concentrated industrial wastewaters are preferably treated in an anaerobic reactor for reasons of energy generation and low surplus sludge production. However, there are problems to be solved in the practical application of the technology. These problems include a low growth rate of the microorganisms, their low settling rate process instability, and the need for after-treatment of the noxious anaerobic effluent which often contains NH4(+) and HS(-). An investigation was undertaken to determine the use of biomass immobilized on small suspended carriers as a suitable means to overcome these problems.

Research at Gist-brocades, Delft, The Netherlands, led to the construction of a full scale plant which utilized an anaerobic pretreatment process and an aerobic posttreatment process. The

anaerobic pretreatment process used a liquid/solid fluidized bed as the reactor. Results revealed that the anaerobic fluidized bed system offered an acceptable alternative in that the process enabled a good anaerobic treatment at high loads and short liquid residence times for

a normal load. The aerobic posttreatment system consisted of an aerobic airlift suspension reactor. The use of this system has shown the process to be efficient for high rate aerobic purification. High biomass concentrations and purification capacities in a difficult wastewater were possible to achieve.

Waste Water Treating Process

Leonard, J P ; Haritatos, N J ; Law, D V

Chemical Engineering Progress Vol. 80, No. 10, p 57-60, October, 1984. 3 Fig, 3 Tab, 1 Ref.

Abstract: The Chevron Waste Water Treating Process (WWT) is an economical method of treating sour water which produces high quality hydrogen sulfide suitable for feeding a sulfur recovery unit, anhydrous ammonia suitable for sale and stripped water suitable for reuse or discharge. The WWT process considered consists of four main processing steps: degassing and feed storage, acid gas stripping, ammonia stripping, ammonia purification and liquefaction. The WWT process is flexible and versatile. The two major reasons for building a WWT instead of a SWSfollowed by an ammonia-burning SRU are the economics of ammonia recovery and improved SRU operation. The economics of the WWT process strongly depend on the amount of ammonia present in the feed. The more ammonia in the sour water, the more incentive there is to recover it as a valuable by-product. Separation of ammonia from the hydrogen sulfide in the WWT has the following advantages for the SRU: elimination of ammonia-related problems in SRU 's such as lower operating factor, plugging in condensers and seals caused by ammonia salts, and catalyst deactivation increased overall sulfur recoveries and reduction in the size of SRU 's and tail gas units because ammonia and the air needed to burn it act as diluents. As an example, consideration is given to a refinery SRU that gets 70% of its acid gas feed from an amine plant with the rest coming from a sour water stripper. The gas from the sour water stripper contains 24 metric ton/d of ammonia. Removing the ammonia from the SRU reduces the SRU feed and combustion air flow ratesby about 45%, thus reducing the size and cost of the SRU. The tail gas flow rate from the SRU is reduced by about 55%. Removing the ammonia diluent from the SRU can also increase the sulfur recovery by as much as 2%. (Baker-IVI)

Preliminary Investigations into the Effects of Refinery Waste Water , and the Single Effect of its Major Pollutants on Commercially Interesting Crops

Al Nakshabandi, G A ; Hameed, Z ; Abdulhadi, A ; Saleem, B

Progress in Water Technology Vol 12, No 3, p 109-117, 1980. 4 Fig, 2 Tab, 4 Ref.

Abstract: The effects of refinery waste water and irrigation water containing NH3, H2S, oil, and phenol on commercial crops were investigated. Corn, barley, alfalfa, and radish were irrigated with solutions containing varying amounts of one of the pollutants, or with a dilution of API separator discharge from KNCP. Germination of the field crops was not affected by any of the pollutants however, radish germination was retarded by 100% and 75% solutions of refinery wastewater. Growth rates of radish, barley, and corn did not differ significantly from controls under all treatments. Alfalfa was affected.Thus, most crops tolerated the different types and concentrations of pollutants, except for heavily polluted waste water used in one test. (Small-FRC)

Designing for Arid Climates

Roberts, D G M ; Banks, P A

Water and Sewage Works Vol 127, No 1, p 59, January, 1980.

Abstract: Special problems encountered when designing sewage systems for arid locations include foul sewage and fouled processes and machinery. Sewage can reach a temperature of 35 deg C and quickly become septic. Also, low per capita water consumption makes the sewage strong and reduces flows. The resulting emission of hydrogen sulfide can cause severe corrosion of concrete and asbestos-cement pipes. Problems can be minimized by avoiding turbulence of the sewage or using forced ventilation. Also, epoxy coatings can be added to the insides of precast and in-situ concrete sewers. In areas of windblown sand, extremely efficient air filters are essential to avoid fine particle dust problems in the system. In activated sludge processes, windblown sand can enter moving machinery and cause increased bearing wear. Sand can also quickly fill small treatment lagoons. Extended aeration requires high power costs, but produces less sludge than conventional plants. (Small-FRC)

Compost Filters for H2S Removal from Anaerobic Digestion and Rendering Exhausts

Rands, M B ; Cooper, D E ; Woo, C P ; Fletcher, G C ; Rolfe, K A

Journal of the Water Pollution Control Federation Vol 53, No 2, p 185-189, February, 1981. 2 Fig, 5 Tab, 5 Ref.

Abstract: The Moerewa Meat Waste Treatment Plant has had problems with the disposal of anaerobic digester gas for the past 20 years. The plant produces an abundance of compost from the periodic removal of sludge from anaerobic solids, balancing tanks, and anaerobic digesters. Pilot plant compost filters for removing waste gases were set up to examine the suitability of such a system to remove odors, especially H2S, and to explore the possibilities of using similar equipment as an alternative to expensive odor control methods. Favorable pilot plant results led to the construction of full-scale compost filter plants in 1978. By 1979, most of the problems had been overcome and the filter was handling the full gas flow from the aerator. An analysis of the screened compost showed it had a bulk density of 0.813 kilograms/liter, and composition values of moisture 45.5%, nitrogen 0.81%, carbon 36.7%,

and ash 33.9%, respectively. The average pH of the compost was 7.82, and the carbon/nitrogen ratio was 45.4. Watering was also instituted to prevent channeling and drying out of the compost and cracking of the retaining walls which gave rise to small leaks.

Fundamentals of Sewer Ventilation as Allied to the Tyneside Sewerage Scheme

Pescod, M B ; Price, A C

Water Pollution Control Vol 80, No 1, p 17-33, 1981. 8 Fig, 9 Tab, 6 Ref.

Abstract: The concentration of hydrogen sulfide (H2S) in the atmosphere of interceptor sewers arriving at the sewage treatment works at Howden, Great Britain, is important due to the proximity of a lead oxide plant which the Northumbrian Water Authority is bound by agreement to protect from exposure to even very low ambient H2S levels. A project was undertaken to achieve continual extraction of air from the sewers and replacement with fresh air so that the oxygen content of the sewer atmosphere would not be a limiting factor in reoxygenation of flowing sewage and would not contribute to the development of H2S in the

interceptor sewers as they approached the treatment plant. Factors which have been identified as contributing to the natural ventilation of sewers include sewage drag, wind-across-vent extraction, difference in temperature between sewer atmosphere and surface ambient air, sewage rise and fall, and change in barometric pressure. A general model for element of sewer length between one educt vent and the next, was developed and applied to the Tyneside sewerage scheme to estimate the oxygen concentration in the atmosphere of a range of sewer sizes. These studies allowed some of the fundamental factors in natural ventilation to be quantified and correlated with influencing variables. Ventilatingair flows were then calculated for the interceptor sewers under varying meteorological conditions. A criterion has been suggested to allow the calculation of maximum distance between educt vents on a sewer which will prevent oxygen deficiency in the sewer atmosphere from affecting bacterial respiration in the flowing sewage. The results have been applied in the design of natural ventilation for the interceptor sewers on Tyneside.

Treatment and Control of Hydrogen Sulfide Odor

Peat Biofilters in Long-Term Experiments for Removing Odorous Sulphur Compounds

Hartikainen, Tarja, University of Kuopio, Finland; Martikainen, Pertti J.; Olkkonen, Minna; Ruuskanen, Juhani

Water Air Soil Pollut v133, n1-4, p335(14), Jan 02

Abstract: At a waste pumping station in Finland, a packed filter bed of fibrous peat was evaluated for the removal of hydrogen sulfide, and in the laboratory, a peat biofilter with a volume of 2 l was studied in terms of the removal of H2S, methyl mercaptan, and dimethyl sulfide. Results from the in situ experiment showed that the native acid peat contained sulfur-oxidizing microbes, as oxidation of H2S occurred without any inoculation, but better removal was achieved using a neutralized peat. The highest S removal achieved with both neutralized and natural peat was 135 g/m3/d. When the natural peat biofilter was limed and inoculated in the laboratory study, a Me2S removal efficiency of 95% was achieved within two weeks. When methyl mercaptan was added to the waste gas containing Me2S, the removal efficiency of the latter was reduced significantly, but the removal efficiency of methyl mercaptan was 99%. When all three gases were present, removal of S averaged 80 g/m3/d. The lifetime of the biofilter decreased with increasing gas load.

Odor Control of an Anaerobic Lagoon with a Biological Cover: Floating Peat Beds

Picot, B., Universite Montpellier I, France; Paing, J.; Toffoletto, L.; Sambuco, J. P.; Costa, R. H. R.

Water Sci Technol v44, n9, p309(8), 2001

Abstract: A floating biological cover was evaluated for controlling odor emission from anaerobic lagoons. The biological cover consisted of a peat bed, and the effects of adding ferric chloride and plants to enhance the efficiency of biofiltration were considered. The study was conducted in five laboratory-scale pond reactors. The pond reactors were found to represent large-scale anaerobic ponds producing hydrogen sulfide. The presence of the floating peat bed significantly reduced H2S emissions, and emission-rate reductions were greatest in the system containing a combination of peat, Fe, and plants. Subsequent analysis of the systems revealed that H2S removed from the biogas was retained in the peat. The addition of ferric chloride increased the complexation of sulfide in the peat filter and improved H2S removal. In the system also containing aquatic ants, plant roots took up most of the S as sulfate, thereby enhancing further the efficiency of the peat bed.

A Pilot Study of a Biotrickling Filter for the Treatment of Odorous Sewage Air

Wu, L., Aromatrix Pte Ltd, Singapore; Loo, Y.-Y.; Koe, L. C. C.

Water Sci Technol v44, n9, p295(5), 2001

Abstract: At a local wastewater-treatment plant in Singapore, biotrickling filtration was used to treat hydrogen sulfide gas. The pilot-scale biotrickling filter was operated under normal operating sewage off-gas conditions, under high H2S loading conditions in the presence of sewage off-gas, and under shock H2S loading conditions in the presence of sewage off-gas. Acclimatization and immobilization of the bacteria are described. Under normal operating conditions, the H2S removal efficiency was 90% at inlet concentrations ranging 0.5-17.8 ppmv. As the H2S loading rate was increased from 20 to 100 ppmv, the removal efficiency decreased to 70%. Performance decreased further under shock loading, but recovery was observed when the H2S concentration was reduced to 50 ppmv, and recovery was complete when the influent concentration was reduced to 20 ppmv.

Simultaneous Activated Sludge Wastewater Treatment and Odour Control

Hardy, P., Cranfield University, Bedford, Beds, UK; Burgess, J. E.; Morton,

S.; Stuetz, R. M.

Water Sci Technol v44, n9, p189(8), 2001

Abstract: Static-vessel tests and pilot-plant experiments were conducted toevaluate simultaneous activated-sludge wastewater treatment and odor control. A range of different activated sludges were used, along with different hydrogen sulfide concentrations. The origin of the activated sludge was found to have a strong effect on the ability to absorb H2S. Best

results were obtained using an industrial sludge, removing 100% of the inlet H2S, which may have been due to previous biomass acclimation. Sparging 5 ppm H2S into the activated sludge did not impact the wastewater-treatment process adversely.

Removal and Decomposition of Malodorants by Using Titanium Dioxide Photocatalyst Supported on Fiber Activated Carbon

Nozawa, M., Tokyo University of Agriculture and Technology, Japan; Tanigawa, K.; Hosomi, M.; Chikusa, T.; Kawada, E.

Water Sci Technol v44, n9, p127(7),2001

Abstract: A compact deodorizing system has been developed that consists of a sheet material comprised of titanium dioxide supported on fiber activated carbon. Results are presented from experiments conducted to evaluate the efficacy of the system for removing ammonia, methyl mercaptan, and hydrogen sulfide from the gas phase. Experiments were conducted in the presence and absence of the sheet material and UV-irradiation. Concentrations of the malodorants and the reaction products were measured by gas detective tubes. Four different combinations of the TiO2/fiber activated C sheet and light sources were utilized. Results showed that NH3 and methyl mercaptan were oxidized to nitrate and sulfate, respectively, by photocatalysts in the presence of both systems, while methyl mercaptan was effectively decomposed with UV irradiation without the TiO2/fiber activated C sheet. The results suggested that the decomposition characteristics of the malodorants varied with the dominant wavelengths of the light sources.

Animal Production and Air Quality

Sweeten, John M., Texas A&M University, Amarillo

USDA Agricultural Outlook Forum 2001, Arlington, VA (8),Feb 22-23, 01

Abstract: Air quality problems commonly encountered in US livestock production operations are surveyed, highlighting ammonia and hydrogen sulfide as odorous gases of most concern. Data gaps are identified in terms of total suspended particulate emission rates and human responses and health effects associated with odors and particulate matter. Current federal and state policies concerning odor and air quality control at animal feedlots are summarized, and prospective approaches to odor control are examined. Research and technology transfer needs are cited.

Feasibility of Fluidized-Bed Bioreactor for Remediating Waste Gas Containing H2S or NH3

Chung, Ying-Chien, National Science Council, Taipei, Taiwan; Liu, Chia-Ho; Huang, Chihpin

J Environ Sci Health-Toxic Hazard Subst & Environ Eng vA36, n4, p509(12),2001

Abstract: A laboratory-scale bioreactor packed separately with immobilized Pseudomonas putida and Arthrobacter oxydans was evaluated for the treatment of gaseous hydro