Abstract: Hydrogen sulfide present in an aqueous system is removed and the production of hydrogen sulfide by sulfate-reducing bacteria (SRB) is eliminated by introducing into the system nitrite and nitrate and/or molybdate ions, whereby denitrifying microorganisms outcompete the sulfate-reducing bacteria for the available carbon nutrients, thus preventing the SRB from producing hydrogen sulfide and the nitrite along with the denitrifying microorganisms remove hydrogen sulfide already present in the system. The system which contains the denitrifying microorganisms and which is essentially free of hydrogen sulfide can enhance oil recovery by means of a microbial enhanced oil recovery mechanisms.

Abstract: The invention relates to a process for treating industrial waste water which comprises either: (a) pre-treating the waste water with at least two different pre-treatments selected from adsorption, membrane filtration and oxidation and then, biologically purifying the waste water or, (b) neutralizing and biologically purifying the waste water and then after-treating the waste water either by membrane filtration in combination with adsorption or oxidation or, by oxidation optionally in combination with adsorption or filtration on a nanofiltration membrane or, by filtration on a nanofiltration membrane.

Abstract: The present invention provides a process for the regulation of the activa sludge step of a clarification plant by control of the decomposition efficiency of the activated sludge, wherein an activated sludge sample is incubated under precisely defined conditions, which are optimised with regard to the pH value, the temperature and the salt concentration, with the substrate or substrates of interest above the saturation range and, in the initial phase, the decrease of the substrate or the increase of a decomposition product is determined kinetically as a measure of the decomposition efficiency for this substrate and the measured value determined is used as regulating value for the control of the clarification plant.

Abstract: In order to investigate an object, such as a culture of micro-organisms, the object is repeatedly captured at two different magnifications by a suitable image pick-up device. The images at the two different magnifications are then analysed by a suitable picture image recognition device and the results of the repeated analysis are compared, thereby to derive a measurement of the change in the object with time. Thus, for a culture of micro-organisms, the number of cells can be determined at one magnification and the number of microscopic spherical bodies can be determined at another magnification, to obtain a measure of the activity of the culture. Preferably, one or more conditions of the object are then controlled on the basis of the measurement of change.

Abstract: The biochemical oxidation of two wastewater feeds, one containing at least ten times more ammonia nitrogen, and the other at least ten times more chlorinated hydrocarbons, than present in a conventional municipal wastewater stream were treated in an aerated packed bed bioreactor inoculated with microorganisms ("cells") especially cultured and acclimated to the task. Arbitrarily shaped pieces of numerous microporous synthetic resinous materials (familiarly referred to as "porous plastics") are discovered to provide not only an excellent packing for the bioreactor, but also a peculiar catalytic function not normally associated with a bio-support. Microporous polytetrafluoroethylene (PTFE foam) appears to be too inert to generate a high level of microbial activity for either feed which was tested, while microporous polyethylene appears to be exactly what the cells ordered.

Abstract: The invention provides a composition for enhancing the biodegradation of biodegradable organic wastes comprising a combination of organic-waste consuming microorganisms and liposomes wherein the liposomes supply essential nutrients for bacterial growth while concomitantly increasing the polarity and wettability of the waste, thereby increasing their availability for enhanced bacterial interaction therewith and methods for the use thereof.

Abstract: A system is provided to treat wastewater from a metal-working facility, such as an automotive manufacturing plant in a bioreactor using live microorganisms. Such wastewater contains waste fluids which are a mixture of relatively easily biodegradable fats and oils, much less easily biodegradable synthetic fluids, oils and greases, and nonbiodegradable material including inorganic finely divided solids such as metal and silicon carbide particles. Such waste fluids require a hydraulic retention time (HRT) and a solids retention time (SRT) which is 10 times greater than for sewage. High quality water is separated from suspended solids which are removed from the reactor at an essentially constant rate and fed to an ultrafiltration membrane. Concentrate is recycled to the reactor, except for a bleed stream to remove solids periodically.

Abstract: The present invention relates to an air emission control system for removing volatile organic compounds (VOCs) and other objectionable contaminants from an emitted gas stream which is generated from a water treatment means. Specifically the improved air emission control system of this invention relates to collecting, dehumidifying, bypassing, diluting, monitoring, purifying recycling and reusing the emitted gas stream, and also relates to feeding an inert gas, upon demand, for reducing oxygen content of said emitted gas stream, in turn, for preventing a gas purification contactor from being ignited and/or exploded due to oxidation of carbonaceous substances inside said gas purification contactor. A complete water treatment and gas emission control system is developed by applying the air emission control system to either single stage water treatment or multiple stage water treatment.

Abstract: A microbial media comprising numerous U type loops having at least two types of fibers woven on a central stay, at least one of these fibers being polyvinylidene chloride, acryl, nylon, polypropylene, polyethylene or carbon; and a waste water treatment method using same.

Abstract: A process for treating effluents, such as precious metal tailings, having a pH of at least 9 and containing cyanide is described in which Caro's acid is added to the effluent having a pH of at least 9 and commencing the reaction of the cyanide with Caro's acid at 0.degree. C. to 80.degree. C. in the absence of an added alkali; adding sufficient Caro's acid within a mole ratio of Caro's acid to cyanide of 0.3/1 to 3/1 to reduce the pH of the effluent to below 9, continuing the reaction between Caro's acid and the cyanide to reduce the amount of cyanide remaining in the effluent and to recover an environmentally compatible effluent reduced in amounts of cyanide.

Abstract: A process for treating wastewater in a dynamic bio-sequenced manner in a single SBR reactor already filled with an activated sludge mixed liquor. In this process which is simple, fast and biologically and hydraulically "on going" and which allows one single SBR reactor to process typically twice as many batches of water per day as is presently processed within the existing SBR process, a given amount of wastewater rapidly introduced into the SBR reactor below the clear water level to cause the level of the wastewater within the tank to raise relatively uniformly and vertically and the supernatant clarified water to enter decantation pipes and be discharged out of the reactor. Then, the scum floating on top of the wastewater is collected and discharged and the mixed liquor is mixed and aerated as long as necessary to achieve the required treatment.

Abstract: A method of biologically purifying liquids that are heavily contaminated with organic or inorganic impurities, by using bacteria in the presence of a solid support on which bacteria can be fixed, comprises the following steps: the liquid to be purified is continuously injected without prior filtering into a reactor in which a solid support having grain size lying in the range 1 mm to 5 mm and density lying in the range 1.01 g/cm.sup.3 to 1.3 g/cm.sup.3 has been put into turbulent motion by blowing in gas in the presence of bacteria and while satisfying the conditions required by the metabolism of the bacteria; and the treated liquid is taken continuously from the reactor after a transit time that is long enough to ensure purification of the impurities contained in the liquid to be purified.

Abstract: A process for treating waste water containing chlorinated organic substances, particularly waste water from production of epichlorohydrin which contains more than 10 mg of adsorbable organic halogen compounds (AOX) per liter, comprising charging the waste water at a pH of 10 to 14 (measured at room temperature) into a reactor and maintaining a temperature of at least 75.degree.C., a pressure of at least 1 bar (abs.), and a residence time of at least 0.5 hours in said reactor, thereby partially dechlorinating and/or dehydrochlorinating chlorinated organic compounds contained in the waste water, and thereafter subjecting the waste water to further dechlorination and/or dehydrochlorination treatment in the presence of a hydrogen-containing gas, a hydrogen-releasing compound and/or a catalytically active material; and optionally subjecting the waste water to a biological treatment with the use of microorganisms; and apparatus for carrying out the foregoing process.

Abstract: The Langelier index and pH of city drinking water are improved by mixing and reacting a slurry of calcium carbonate and slaked lime covered with calcium carbonate produced in a slaked lime dissolving vessel with carbonic acid-containing water in a mixing and reacting vessel to make a calcium hydrogen carbonate aqueous solution which in turn is continuously added to water in a water-receiving vessel together with the aqueous solution of slaked lime. As a result, unused undissolved matter is decreased, and the Langelier index of drinking water can be improved.

Abstract: Method for the anaerobic decomposition of degradable organic waste and for the extraction of biogas from the latter in a reactor (1), according to which method the waste is put in a reactor (1) which contains an active, anaerobic, methanogene biomass and which is exposed to anaerobic fermentation without any mixing in the reactor (1), characterized in that the waste is supplied in the shape of a semi-solid or solid organic substrate at the top of the reactor, in that a phase separation into a liquid phase (6) and a solid phase (4) is allowed in the lower part of the reactor, whereby at least during a fermentation period without any mixing in the reactor (1), a liquid phase (6) is secreted at the bottom in the reactor (1) from a top solid phase (4), in that this liquid phase (6) is removed before fresh substrate is supplied, whereby a maximum amount of solid phase (4), namely substrate and biomass, is retained, and in that, after the removal of the liquid phase (6), the solid phase (4) is removed from the reac

Abstract: The invention relates to a bioreactor unit for the aerobic biological treatment of hydrocarbon contaminated waste water and off-gases. The bioreactor comprises a biotreatment chamber comprising a vertically extending housing unit forming the walls, floor and ceiling of the biotreatment chamber. The housing unit also comprises a door for accessing the biotreatment chamber. The biotreatment chamber also comprises waste water inlet means for discharging waste water under pressure from the upper portion of the biotreatment chamber, onto a plurality of superimposed water treatment trays disposed substantially horizontally inside the chamber, the water treatment trays being adapted for retrieval from the biotreatment chamber through the door of the housing unit. Each water treatment tray has at least one bottom porous section adapted to receive contact media.

Abstract: A method for treating water comprises:(a) connecting a plurality of tanks each capable of holding water in series such that water can be transferred along the series of tanks from a first tank to a last tank, wherein each of the tanks comprises a bottom and light-transmitting sides;(b) stocking the tanks with water and organisms for removing pollutants from the water,(c) inputting water containing pollutants to the first tank; and(d) outputting water from which said pollutants have been removed from the last tank.

Abstract: A process and an apparatus for treating waste water in oxidations ponds, oxidation ditches, or other bodies of water in a waste water treatment facility to abate the malodors caused by the presence of volatile contaminants. In the process, a water stream is withdrawn from the body of waste water and contacted with an air stream in an air-water contact apparatus. The water stream is thereby aerated and stripped of potentially odor causing volatile contaminants and an off-gas stream is produced containing the stripped volatile contaminants. At least a portion of the aerated and stripped water stream is returned to the body of waste water to inhibit anaerobic decomposition of organic impurities.

Abstract: The present invention relates to a sewage disposal apparatus employing large buoyant filter media and is directed to prevent effectively clogging in these filter media. The intended object of the invention can be attained by circulating the filter media by a circulation arrangement to allow the filter bed as a whole to flow very calmly, and more efficiently by removing sludge deposited on the filter media utilizing the circulatory movement of the filter media.

Abstract: Wastewater is treated by promoting the presence and growth of BPR organisms, which have the ability to absorb and retain an amount of phosphorus in excess of the amount required by the BPR organisms for metabolism and cell growth. In the process, a mixture of influent wastewater (10) and activated sludge (14) containing BPR organisms is first subjected to a period of incubation in an anoxic zone (20) followed by a period of incubation in an anaerobic zone (30). Volatile fatty acids (VFA's) (16) are added in the anaerobic zone (30). The mixture is then subjected to an aerobic zone (41). The wastewater mixture (46) leaving the aerobic zone is clarified in a clarifier (50), causing activated sludge to settle. The activated sludge contains BPR organisms which are engorged with phosphorus absorbed from the wastewater. The clarified wastewater (52) becomes effluent from the system. The activated sludge (54) is removed from the clarifier (50).