4632758 Anaerobic wastewater treatment system

PATENT ABSTRACTS An improved method of reducing the nitrate, nitrite and ammonium compound content of an aqueous tobacco extract employing microorganisms is described. The nitrates, nitrites and ammonium compounds are eliminated on a continuous basis via an aerobic assimilatory metabolic pathway by introducing aqueous tobacco extract and necessary additives into a work mixture, containing suitable microorganisms, at a dilution rate which does not exceed the growth rate of the microorganisms while withdrawing a portion of the work mixture at a rate such that the volume of the work mixture remains constant. Optionally the biomass may be removed from the withdrawn mixture.

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An anaerobic apparatus for treating wastewater is disclosed. The treating apparatus comprises a reactor housing a media having a plurality of surfaces for receiving bacteria. The wastewater that is to be treated, is introduced into the bottom of the reactor and forced up over the surfaces of the media, whereby the bacteria on the surfaces of and in the voids of the media consume the organic materials in the wastewater by an anaerobic digestion process to produce methane and a biological sludge. The biological sludge is collected and stored in a bottom storage portion of the reactor, whereby further digestion occurs to condense the mass of such sludge. A first conduit array is disposed above the media for withdrawing the treated wastewater. A second conduit array is disposed in communication with the storage portion for withdrawing biological sludge from the reactor.

REMOVAL OF DIOXINS, PCB'S AND OTHER HALOGENATED ORGANIC COMPOUNDS FROM WASTEWATER

4632759

Wei-ch Ying, Stanley Sojka assigned to Occidental Chemical Corporation

WASTEWATER TREATMENT METHOD

Combinations of physicochemical and biological treatment processes are capable of removing dioxins, polychlorobiphenyls (PCB's) and other halogenated organic compounds from wastewaters. The dioxins and PCB's are removed by at least 90 percent in the pretreatmerit steps of neutralization, oxidation, and sedimentation; the residual amounts are removed in a powdered activated carbon enhanced sequencing batch reactor (PAC-SBR) operating at a high mixed liquor suspended solids concentration ()5000 rag/L). Powder activated carbon (PAC) is supplemented to the bioreactor to ensure complete removal of the dioxins ((0.8 ppt) and PCB's ((2 ppb). The PAC-SBR enhanced biological treatment process is capable of meeting stringent effluent limits on not only on dioxins and PCB's but also on other toxic halogenated organic compounds. The treatment cost of this process is substantially less than either the conventional granular activated carbon adsorption technology or two stage treatment of biodegradation and carbon absorption.

Per-Erik Andersson, Thomas G Welander, Sundsvall, Sweden assigned to'Purac Aktiebolag

4632758 ANAEROBIC WASTEWATER TREATMENT SYSTEM Thomas E Whittle assigned to Commonwealth Engineering & Technology lnc

At anaerobic treatment of wastewater it was found that resin and fatty acids in the wastewater have a toxic effect on the bacteria culture. According to the invention, this is solved by additions of iron or aluminium and calcium or magnesium.

8605770 AN APPARATUS FOR THE PURIFICATION OF WATER, WASTE WATER IN PARTICULAR, BY A B I O L O G I C A L O X I D A T I O N METHOD Vilho DUNDER, Storgatan 40, S-95300 Haparanda, Sweden assigned to 1NSIN@@RITOIMISTO LUJARi OY The apparatus comprises a biorotor (2) preferably formed by a sector modules (20), within which biorotor a granular medium (1 I) is provided to form a substrate for the biomass, said medium simultaneously serving as a hydraulic bearing during the rotation of the rotor partly immersed in water so that it holds up the entire biorotor structure as well as the active biomass.