Abstract: Apparatus and a method are disclosed for reducing sulfate contained within a flowable material to hydrogen sulfide by the use of two stages of reaction. The flowable material is deoxygenated and then introduced into a first reactor which contains a sulfate reducing bacteria such as a Desulfovibrio or Desulfotomoculum. Hydrogen sulfide is removed from the first reactor and the remaining portion of the flowable material is subjected to a separating action to produce a supernatant component and a sludge component. The sludge component is reintroduced to the first reactor which is generally devoid of packing or support and the supernatant is introduced into a second reactor which is preferably in the nature of a supported film reactor. Mixed products including carbonate may be removed from the first reactor. The second reactor also contains anaerobic sulfate reducing bacteria. Hydrogen sulfide, low sulfate water and carbonates may be withdrawn from the second reactor.

Abstract: A method is disclosed for the biological aerobic purification of waste waters wherein a temperature from 30.degree. to 60.degree. C. is maintained in a first process stage and a temperature from 20.degree. to 40.degree. C. is maintained in a second process stage, with the temperature in the first process stage always being higher than the temperature in the second process stage and wherein a part of the activated sludge of the second process stage, after being seperated, is returned to the first process stage. The process provides a high decomposition output and produces an activated sludge which exhibits good sedimentation behavior.

Abstract: The present invention relates to the use of non-floating, non-abrasive, highly-filled polyurethane (urea) compositions of high water-absorbability, which during their production contain no cells capable of growth as carriers for biomasses in the biological treatment of waste-containing liquids. These carriers have a filler content of greater than 15% by weight and less than 95% by weight (based on the moisture-free weight of the filler-containing polyurethanes). The fillers are selected from the group consisting of natural materials containing finely-divided fossil lignocelluloses or the secondary products thereof (e.g., peat, lignite, mineral coal or coke), active carbon, finely-divided distillation residues, inorganic fillers, homogeneous or cellular plastics particles (and more particularly polyurethane foam (waste) particles) and mixtures thereof. The polyurethane (urea) is a hydrophilic and/or hydrophobic polyurethane(urea), and preferably contains cationic groups.

Abstract: Process for denitrifying subterranean waters to make them potable. The sub-soil is employed as an infiltration site. Wells (3,4), for example four in number, surround a catchment well (5). The wells (3,4) are filled with a mixture based on straw and marl, to permit the denitrification reaction by a heterotrophic route by virtue of the bacteria present in the sub-soil and particularly in the subterranean waters. The denitrified water arrives at the catchment site (5) where it is withdrawn for the distribution (at 7) and for injection (8,9) into the infiltration sites (3,4). A simple, effective and inexpensive process is thus available for making potable the waters from subterranean tables.

Abstract: A method and apparatus for the purification of water or other contaminated aqueous liquids. The water is passed through a filter comprising a solid backwashable filter medium preferably having pores or slots of 125 microns (0.005 inches) or less made of biologically nondegradable and non-corrosive material, and having a specific, non-pathogenic aerobic activated sludge layer deposited thereon. The aerobic sludge layer is prepared by aerating mixtures of raw water, diatomaceous earth and preferably an inert particulate biologically non-degradable filter material (such as cellulose powder), for a minimum period of 24 hours, and preferably at least five days. The resulting mixtures containing a specific, non-pathogenic aerobic activated microbiological sludge is recirculated through the solid filter medium in a specific sequence until an activated sludge layer is deposited thereon to the desired thickness.

Abstract: In the biological purification of wastewater containing organic impurites, wherein the wastewater is passed through a reaction (1), e.g., continuous flow-stirred tank having circulating means (12) to achieve thorough mixing therein, or a fluidized bed or suspended bed type reactor, the wastewater is aerated in the presence of activated sludge with an oxygen containing gas fed through a gas feed conduit (9), and in a post clarification stage (5), the wastewater-activated sludge mixture from the reactor (1) is separated into purified water and sludge, the improvement comprises conducting the biological purification in the reactor (1) in the presence of a carrier material for microorganisms. The carrier material comprises particles of macroporous material having a low specific gravity, and in piece and/or granulated form in an amount such that the suspended individual particles are freely movable in the wastewater. Soft polyurethane foam particles are especially preferred as the carrier materail.

Abstract: A process is provided for reducing the concentration of water soluble ionic heavy metal species and sulfate ions in aqueous waste solutions containing the same. The process comprises passing said waste solution through a treatment zone containing a porous matrix on which are retained populations of at least one bacteria of the genera Desulfovibrio and Desulfotomaculum. The passing of said aqueous solution through said treatment zone is carried out at predetermined rates of flow, and contact between said solution and said bacteria is conducted under anaerobic conditions and at predetermined pH and temperature levels. The process provides for the conversion of the water soluble sulfate ions to hydrogen sulfide and reaction between said hydrogen sulfide and water soluble ionic heavy metal species to water insoluble heavy metal species which are substantially retained on the porous matrix and which are recoverable therefrom.

Abstract: In the treatment of wastewater, the mixture of wastewater and the sludge is transported through a treatment zone, and then through a filter zone containing a bed of support particles, e.g., particles of polyurethane foam, to deposit the biomass onto the support particles. The loaded support particles are subsequently regenerated within the filter zone by means of a regenerating means in the same area as the filter zone, e.g., by strong aeration or by being compressed between press-rolls, whereby the system requires neither additional land for regeneration of the support particles nor a secondary settling tank.

Abstract: A process is provided for reducing the concentration of water soluble ionic selenium species in aqueous waste solutions containing the same. The process comprises passing said waste solution through a treatment zone containing a porous matrix on which are retained populations of at least one bacteria of the genus Clostridium. The passing of said aqueous solution through said treatment zone is carried out at predetermined rates of flow, and contact between said solution and said bacteria is conducted under anaerobic conditions and at predetermined pH and temperature levels. The process provides for the conversion of the water soluble ionic selenium species to water insoluble selenium metal, which metal is retained on the porous matrix and can be recovered therefrom.

Abstract: A process is provided for reducing the concentrations of water soluble ionic selenium species, sulfate ion and ionic heavy metal species in aqueous waste solutions containing the same. The process comprises passing said waste solution through a treatment zone containing a porous matrix on which are retained populations of at least one anaerobic bacteria of the genus Clostridium and at least one anaerobic bacteria selected from the group consisting of bacteria of the genera Desulfovibrio and Desulfotomaculum. The passing of said aqueous solution through said treatment zone is carried out at predetermined rates of flow and contacts between said solution and said bacteria is conducted under anaerobic conditions and at predetermined pH and temperature levels.

Abstract: A process and apparatus are provided for the biological purification of phosphate-containing wastewater, wherein the wastewater is treated, in the presence of activated sludge at least a portion of which is fixed on a carrier material. The process is conducted in at least one aerobic, an anaerobic, and optionally an anoxic zone, to thereby discharge a substantially phosphate-free wastewater stream. In order to attain a high purifying effect with low cost expenditure, the activated sludge is carried on a movable carrier. The carrier material is conveyed from the anaerobic zone, optionally through the anoxic zone, to the aerobic zone, and simultaneously a like amount of carrier material is returned from the aerobic zone, optionally through the anoxic zone, to the anaerobic zone. In this process, the activated sludge is enriched with phosphates, and a portion of the phosphate-enriched activated sludge is separated from the discharged effluent.

Abstract: This invention relates to a process for the biological purification of wastewater in at least two immediately successive treatment stages, followed by a post clarification stage wherein the process is adapted so that a wastewater-activated sludge mixture in one of the treatment zones exhibits only a minor biological load and a nitrification process is conducted therein. In accordance with the invention, an intermediate clarification tank is not required due to substantially all biological degradation having occurred in the stage immediately before the nitrification stage. To enhance nitrification a macroporous carrier material for supporting nitrifying bacteria, for example, activated carbon or polyurethane foam, is added into this nitrification treatment stage. The material can be readily retained in the nitrification zone by providing appropriate retaining means. This process offers the advantage that the concentration of nitrifying agents, i.e.

Abstract: In a two stage activated sludge plant, where in the first stage the major proportion of the organic pollutants is decomposed and in the second stage the decomposition of the residual organic pollutants is conducted in conjunction with nitrification, the nitrifying bacteria are fixed on a low-density, macroporous carrier, e.g., particulate, polyurethane, optionally with activated carbon as well. The second stage can be operated as a mixed activated sludge tank or a biological filter, and in either case, it is possible to avoid a post clarification stage.

Abstract: A process for waste water disposal is herein disclosed, in which waste water of high BOD concentration is subjected to an aeration treatment in an aeration vessel so as to reduce the BOD concentration thereof by circulating within said aeration vessel a quantity of coal or active carbon of which 80% or higher is of particle size between 2 and 5 mm and less than 50% is of particle size difference within a range of 0 to 0.5 mm, and microorganisms implanted thereon. Said aeration vessel is adapted for effective disposal of waste water of high BOD concentration without any requirement of water dilution and comprises a pair of long side walls, a pair of short side walls, a bottom wall defined by these pairs of side walls, an upper opening, wherein a lower portion of one long side wall is at an angle of 45.degree. to 60.degree. with respect to the horizontal, and a plurality of air blower pipes provided along the inner surface of the other long side wall adjacent said bottom wall.

Abstract: A process for treating wastewaters with a powdered adsorbent and one or more fixed media filters, wherein biological oxidation occurs. The adsorbent is optionally regenerated and reused. In multistage operation, adsorbent is contacted with wastewater in stagewise countercurrent flow, through each fixed media filter and subsequent clarifier, or through clarifier only.

Abstract: Disclosed is a process for treating waste water through the use of activated carbon. The carbon is generally added to waste water having a pH from about 4 to about 11, and is commonly added after the waste water has undergone primary treatment. Preferred modes of operation comprise using low concentrations of activated carbon having a high surface area and a zeta potential greater than about -10 millivolts. It is also preferred to use activated carbon in conjunction with an activated sludge process having an average sludge age greater than about ten days, especially where the waste water undergoes a pretreatment prior to the activated sludge process to reduce chemical oxygen demand, oil and solids content. Low concentrations of activated carbon based on feed waste water are generally used while maintaining substantially higher carbon concentrations in the process.

Abstract: The invention relates to method and apparatus for the treatment of wastewaters using a rotating biological contactor in combination with an adsorbent.

Abstract: In the activated sludge process for treating wastewater loss of biologically active microorganisms from the aeration-mixing tank to the clarifier is reduced and the biological process whereby wastewater is treated is made more efficient by the addition of inert solid particulate matter to the liquid while in the aeration tank to provide mobile sites upon which the organisms will attach and grow.

Abstract: Fired clays, in the form of medium-sized granulates containing small quantities of trace elements which serve as nutrients for microorganisms, are used as substrates for biological filters.

Abstract: A process for removing the vapors of certain fluoro(alkyl vinyl ethers) from a mixture with the vapor of tetrafluoroethylene by contacting the mixture of vapors with a chilled aqueous liquid coolant solution that is substantially immiscible with the ethers. The process provides an advantageous method for recovering the fluoro(alkyl vinyl ether) monomer remaining in the polymerization kettle after it has been copolymerized with tetrafluoroethylene.