Abstract: A bioreactor that has an internal sludge return function for treating wastewater is provided. Said bioreactor comprises a mixing zone (18), a static zone (28), and a mixed liquor circulation channel (26). The internal sludge return is accomplished by the integration of said static zone (28) that settles sludge, and said mixed liquor circulation channel (26) that provides a circulating stream of the mixed liquor for carrying settled sludge back to the mixing zone (18). Therefore, the microorganism concentration in the bioreactor of this invention is increased compared with conventional suspended-growth bioreactors, resulting in the improved wastewater treatment performance, reduced bioreactor size, simplified operation, reduced clarifier size, etc. The bioreactor of this invention can be operation in aerobic, anoxic, and anaerobic conditions to serve various wastewater treatment purposes.

Abstract: The present invention is directed to a pulsed electric-field system for rupturing and destroying molecular cellular units of waste-activated sludge to thereby liberate intracellular water molecules from the solids-content thereof. The waste-activated sludge is contained in waste sludge, such as paper-pulp sludge, municipal waste sludge, animal or plant waste sludge. The pulsed-electric field is generated by an electroporating device producing a non-arcing pulsed electric field. The released intracellular dissolved/organic matter may be recycled back to an aeration tank for supplying food to bacteria of the aeration tank for performing aerobic digestion thereon, whereby the intracellular, dissolved organic matter is used as food for the bacteria of the aeration tank, whereby the aerobic digestion process is accelerated.

Abstract: A method of treating sewage or waste water for removing nitrogen and phosphorus as well as organic materials in the sewage or waste water, and an apparatus therefor are provided. The method applies intermittent aeration and dynamic flow to an equipment having at least a pair of reaction basins with intermittent aeration means, a clarifier with sludge transfer means, and a filter for passing liquid without passing solid between the reaction basins. According to the method, the efficiency of removing nutrient salts is excellent and stable even in the treatment of waste water having low content of influent organisms and low C/N ratio.

Abstract: A waste water treatment process for biologically removing phosphates incorporates a membrane filter. The process includes three zones, an anaerobic zone, an anoxic zone and an aerobic zone containing an anaerobic, anoxic and aerobic mixed liquor. Water to be treated flows first into the anaerobic zone. Anaerobic mixed liquor flows to the anoxic zone. Anoxic mixed liquor flows both back to the anaerobic zone and to the aerobic zone. The aerobic mixed liquor flows to the anoxic zone and also contacts the feed side of a membrane filter. The membrane filter treats the aerobic mixed liquor to produce a treated effluent lean in phosphorous, nitrogen, COD, suspended solids and organisms at a permeate side of the membrane filter and a liquid rich in rejected solids and organisms. Some or all of the material rejected by the membrane filter is removed from the process either directly or by returning the material rejected by the membrane filter to the anoxic or aerobic zones and wasting aerobic sludge.

Abstract: A system that allows the flexibility of primary and secondary treatment of municipal sludge, paper-pulp sludge, animal and plant waste, whereby the treatment thereof via electroporation may be used either as the primary dewatering treatment, secondary dewatering treatment, direct WAS-treatment, and combinations with other conventional dewatering techniques, in order to provide the municipal treatment plant, or the paper-pulp treatment plant, with the most cost-effective and efficient system as possible. The electroporated-treated sludge releases hitherto unreleased biosolids exiting from the PEF-electroporation system, which are returned to aeration tanks. The electroporation process causes the release of intracellular dissolved/organic matter, which is used as “food” for the bacteria of the aeration tanks.

Abstract: A process for biological purification of waste water by the activated sludge method wherein the waste water is continuously passed through one or more treatment zones and a clarification zone, wherein the waste water treated in the last treatment zone at the outlet from the zone under suitable control of aeration and stirring is continuously divided into a predominantly aqueous fraction and a sludge-containing fraction, and wherein a portion of the sludge fraction is recirculated and mixed with non-treated waste water, of which the former is subjected to clarification, and the latter is recirculated to the same or a preceding treatment zone.

Abstract: A residence (13) discharges its waste water into a septic tank (10). A pump (18) draws waste from the tank's liquid layer and feeds it to a distiller (22) as distiller feed. The distiller (22) divides the distiller feed into distillate and distiller residue. The distiller residue is returned to the septic tank (10), whereas the distillate is reused or discharged into a leach field. In either case, the adverse environmental effects of leach-field use are largely eliminated.

Abstract: One or more flow equalization basins or lagoons are utilized for performing hydrolysis of ATP as the first stage of biological phosphorus reduction, selective reduction of biological oxygen demand (BOD), deamination, and denitrification of nitrate and nitrite compounds, in addition to simultaneous flow equalization of wastewater produced by food processing operations on a 2-to-6-day schedule. The inflow half of a single basin or an entire first basin is. operated on an anaerobic/anoxic basis. The outflow half of the single basin or an entire second basin, if present, is operated on an anoxic/aerobic basis. A downstream nitrification reactor is operated on an aerobic/anoxic basis or is operated exclusively on an aerobic basis if followed by an anoxic reactor.

Abstract: The invention relates to a method for purifying protein containing waste water, In which a) a first insoluble material is caused to form in the waste water, b) the mixture obtained in step a) is separated to form pre-purified waste water, c) the pre-purified waste water is treated with aerobic microorganisms and d) the mixture obtained in step c) is separated to form finely purified waste water, and in which step b) and step d) are carried out in the same device. Preferably, steps b) and d) are alternately carried out in the same device.

Abstract: A bioprocessing system for a feed such as wastewater comprises an anaerobic reactor subsystem, an aerobic reactor subsystem, and a recycle loop for partial recycling of the aerobic reactor subsystem effluent. The anaerobic reactor subsystem is capable of providing anaerobic processing of the wastewater in the substantial absence of aerobic processing of the wastewater. The anaerobic reactor subsystem can include a single anaerobic reactor or a plurality of reactors. The aerobic reactor subsystem is in direct communication with the anaerobic reactor subsystem, with the aerobic reactor subsystem being capable of providing aerobic processing of the wastewater in the substantial absence of anaerobic processing of the wastewater. The aerobic reactor subsystem processes the wastewater from the anaerobic reactor subsystem without intervening bioprocessing of the wastewater. As with the anaerobic subsystem, the aerobic reactor subsystem can include a single aerobic bioreactor or a plurality of reactors.

Abstract: A method of biologically cleaning polluted water uses active sludge and at least three zones, where at least one zone operates as a biological treatment zone and at least two zones variably operate as a biological treatment zone and as a clarifying zone. By this method, the polluted water is fed to a zone operating as a permanent biological treatment zone, where a back-mixing is performed during a period between this zone and a zone variably operating as a biological treatment zone and which has operated as a clarifying zone during a previous period. As a result, the drawbacks are overcome which the known T- and V-channel methods are encumbered with.

Abstract: The invention provides a system 10 for treatment and purification of domestic household effluent, and for the elimination within said system of organic solid wastes, comprising elements 12 and 14 for separately collecting first and second constituents of the sewage of a domestic residential unit, lavatory sewage comprising said first sewage constituent, and bath, shower, wash basin, laundry, kitchen sink sewage and the like comprising said second sewage constituent, a first and a second dual-purpose vessel 22 and 24, each vessel having at least one inlet port 18 and 20 and at least one outlet port 26, 28, 30, 32 and being arranged so that during the time period that one of said vessels 22 receives said first sewage constituent and acts as a collector and settling tank, the remaining vessel 24 operates as an anaerobic reaction vessel, the vessel operating as an anaerobic reaction vessel carrying out a decomposition process during which the volume of sludge 34 contained therein is greatly reduced by conversion

Abstract: A method of treating an organic waste water, which is capable of separating and recovering phosphorus components in a liquid or solid form, is provided. According to the method of the present invention, reuse of phosphorus components can be facilitated, while the content of phosphorus components contained in a large quantity of a primary treated liquid can be reduced.

Abstract: A method and apparatus for in-sewer wastewater treatment comprising steps of largely spontaneously growing acidogenic bacteria in sewer lines and providing methanogenic bacteria in these lines. Methanogenic bacteria can be grown using wastewater, solid, or other waste, or other organic feedstock as a substrate. Methanogenic bacteria can be cultivated at a wastewater treatment plant or at other locations in special reactors, or provided from anaerobic wastewater pretreatment plants. Digestion gases can be either vented out or collected and used.

Abstract: In a sealed container, organic material, more especially biowaste is composted. The exhaust air from the sealed container is purified in an exhaust air cleaning unit. In order to improve the cleaning effect, the condensate water from the exhaust air cleaning unit is supplied to a high performance bioreactor, in which it is brought into contact with atmospheric oxygen and is agitated. The suspension leaving from the bioreactor is caused to flow in a circuit through an ultra-filtration module for purifying the water.

Abstract: A reusable immobilized microbial composition is formulated. The formulated microbial composition comprises a synergistic mixture of the bacterial strains of Enterobacter cloaca, Citrobacter amalonaticus, Pseudomonas aeruginosa,Yersinia enterocolitica, Klebsiella oxytoca, Enterobacter sakazaki and Serratia liquefaciens. The formulated microbial composition is immobilized on an appropriate immobilizing agent to form beads. The said beads are tested as microbial seeding material for BOD analysis using Glucose Glutamic Acid (GGA) as a reference standard. The obtained BOD values by the formulated beads are compared with BOD values obtained by sewage as seeding material using synthetic samples as well as industrial effluents. The formulated microbial beads are ready-to-use as well as reusable seeding material in BOD analysis. The said beads can be reused up to five times with same efficacy.

Abstract: A method and plant for the purification of polluted water by the activated sludge method is provided in that a mixture of polluted water and recycled sludge is subjected to biological treatments in at least two treatment zones, and maintaining for a period such conditions in one of the treatment zones that a sludge precipitation occurs therein, supplying in a subsequent period the mixture of polluted water and recycled sludge directly or indirectly to the zone which, during the preceding period, served as a sludge precipitation zone prior to further treatment thereof in one or more treatment zones, and passing the treated water to a permanent clarification zone and separating it into a water fraction and a sludge fraction, at least a part of the sludge fraction being recycled and mixed with polluted water.

Abstract: Method for sewage water treatment using suspended activated sludge where sewage water is supplied to the equalizing tank being then re-pumped to the activation tank from which is supplied to the post-sedimentation tank after the clearing process and from here, after the remaining sludge sedimentation, to the drainage. The activation process is automatically interrupted after a drop of the sewage water level in the equalizing tank below the minimum level setting and the excessive sludge is then pumped off from the activation tank. The sludge re-pumping is interrupted and the activation process restored owing to the subsequent raising of the sewage water level in excess of the operation level setting.

Abstract: The biological process is for treating wastewater in order to remove the phosphorus therefrom and thus obtain clarified water. The process is using two sequencing batch reactors (SBR) in series filled with a sludge-mixed liquor. The process consists of: continuously feeding wastewater into the first (SBR) operating under anaerobic conditions for equalization and anaerobic treatment by controlling in-time any fermentation reaction occurring therein in order to produce an acidogenesis fermenting phase of organic materials and prevent the methanogenesis phase. Then, the fermented wastewater from the first SBR is rapidly transferred by batch into the second SBR. In the second SBR, the wastewater is first anaerobically treated to store a maximum amount of volatile fatty acids (VFAs) in the phosphorus removal biomass.

Abstract: A wastewater treatment process having improved solids separation characteristics and reduced biochemical oxygen demand (BOD) in the purified wastewater comprising the steps of: passing wastewater containing suspended solids and biodegradable organic substances through a main aerobic biological oxidation zone; passing the effluent from said aerobic biological oxidation zone to an aerobic/mixing zone and therein mixing said effluent with effluent from the anoxic/anaerobic zone; passing the effluent from said aerobic/mixing zone to a settling zone and therein separating purified wastewater and sludge containing suspended solids; passing a portion of the sludge formed in the settling zone and volatile acids to an anoxic/anaerobic zone; and recycling an effective amount of the effluent from said anoxic/anaerobic zone to said aerobic/mixing zone.

Abstract: A method of biological treatment of materials by a combination of at least two groups of microorganisms forming sludges in at least two biological treatment zones treating the said materials wherein for purposes of increasing the treatment efficiency and stability at least one said sludges is conditioned in at least one sludge conditioning zone, whereby converting at least a fraction of at least one said group of organisms into organisms of another group, and thus forming the conditioned sludge, and the said conditioned sludge is fed in at least one said biological treatment zone.

Abstract: The present invention relates to a process and a treatment system for biologically removing phosphorus and nitrogen from wastewater. In the anaerobic contact and settlement zone 1, wastewater 7 is first mixed with the returned activated sludge 8 to form a mixed liquor which is then allowed to settle in zone 1, and organic matters present in influent are mostly taken up by the sludge. The supernatant from zone 1 is passed through an aerobic reaction zone 2, furnished with packings, for complete nitrification; the settled sludge from zone 1 is hold in an anaerobic zone 3 for a sufficient period of time for controlling the sludge carbohydrate content to low levels in order to enlarge the sludge capacity for phosphorus removal because the extended anaerobic sludge degradation in zone 3 is very effective in controlling the sludge carbohydrate content to low levels.

Abstract: A method for treating waste water which comprises passing the water through a series of steps including sequentially passing the water through an aeration step, and then a plurality of treatment cells wherein each treatment cell comprises a trickle filter cell. The waste water is subsequently subjected to a denitrification step and to a dephosphorization step. It is then passed through a trickle filter cell and optionally may be treated by passing through a cell wherein the waste water is in contact with peat moss.

Abstract: A first reaction/adjustment tank has a lower portion containing a calcium carbonate mineral, an upper portion containing a calcium carbonate mineral and a plastic filler, and an air lift pump for circulating waste water from the lower portion to the upper portion. Exhaust gas is introduced into a space. A second reaction/adjustment tank has a lower portion containing a calcium carbonate mineral and charcoal, and an upper portion containing charcoal and a plastic filler. Waste water circulates sequentially through the lower and upper portions of the first reaction/adjustment tank, and the lower and upper portions of the second reaction/adjustment tank. Exhaust gas circulates sequentially through the upper portion of the first reaction/adjustment tank and the upper portion of the second reaction/adjustment tank.

Abstract: This invention refers to an original solution for the purification of contaminated water streams with the activated sludge method, involving: a) a two-stage aeration system operating at high rate and low rate conditions respectively, where the first stage operates in anoxic conditions promoting denitration, whereas the second stage operates under oxidant conditions so that nitrates are removed to an extent of 70%; b) a system for moving the biological sludge, where the sludge produced in the first aeration tank is totally rejected, and that produced in the second aeration tank is recycled to the first.

Abstract: A hybrid system and related process for the removal of biological nutrients from wastewater. The system provides an activated sludge system, including both a single-sludge reactor and clarification unit, flowably connected with a final aquaculture pond for final polishing of BOD from the clarified mixed liquor supernatant.

Abstract: A wastewater treatment apparatus is provided which includes at least an aeration chamber and a clarification chamber having a common wall therebetween, a transfer port opening through the common wall between a lower portion of the clarification chamber and the aeration chamber, an aerator mechanism in the aeration chamber for creating wastewater flow currents which flow through an inlet portion of a flow augmenting device located in the common wall above the transfer port. The flow augmenting device is a conduit or pipe having a discharge outlet adjacent the lower portion of the clarification chamber through which exits the flow from the aeration chamber resulting in solid particles being agitated and returned from the clarification chamber lower portion into the aeration chamber through the transfer port.

Abstract: Process and plant for biological purification of polluted water wherein the polluted water is successively subjected to an anaerobic, anoxic and aerobic treatment in the presence of microorganisms, and wherein the anaerobic and the anoxic treatment are carried out in the presence of one or more microorganism cultures which are different from the microorganism culture used in the aerobic treatment. Hereby better exploitation of organic matter in the water is obtained thus improving the removal of nitrogen, and an increased reaction rate per unit mass of biomass is obtained thereby allowing the amount of biomass to be reduced or the total reaction rate of the plant to be increased.

Abstract: A wastewater treatment process having improved solids separation characteristics and reduced biochemical oxygen demand (BOD) in the purified wastewater comprising the steps of: passing wastewater containing suspended solids and biodegradable organic substances through a main aerobic biological oxidation zone; passing the effluent from said aerobic biological oxidation zone to an aerobic/mixing zone and therein mixing said effluent with effluent from the anoxic/anaerobic zone; passing the effluent from said aerobic/mixing zone to a settling zone and therein separating purified wastewater and sludge containing suspended solids; passing a portion of the sludge formed in the settling zone and volatile acids to an anoxic/anaerobic zone; and recycling an effective amount of the effluent from said anoxic/anaerobic zone to said aerobic/mixing zone.

Abstract: A method of treating municipal or industrial wastewater containing undesired concentrations of ammonium or nitrate ions comprising treating the wastewater under anoxic, denitrifying conditions with denitrifying bacteria to reduce the concentration of nitrate ion and produce nitrogen gas and a denitrified liquor; treating the denitrified liquor in an aerobic vertical shaft bioreactor with an oxygen-containing gas to effect BOD removal by the bioxidation of organic compounds in the denitried liquor and produce carbon dioxide off-gas and a shaft bioreactor effluent liquor; clarifying a first portion of the shaft bioreactor effluent liquor to provide a first clarified liquor and a second portion of the shaft bioreactor effluent liquor to provide a second clarified liquor; treating the first clarified liquor under aerobic, nitrifying conditions with nitrifying bacteria, an oxygen-containing gas and the off-gas to oxidize ammonium ion to nitrate ion and provide a first nitrified liquor; recycling by adding the firs

Abstract: A process for biologically removing nitrogen and other nutrients from wastewater using recycled activated sludge. A mixed liquor is formed from influent wastewater and recycled activated sludge and then treated in two successive nitrogen removal stages, each stage having an anoxic denitrification zone and an aerobic nitrification zone. The first nitrogen removal stage entails circulating the mixed liquor back and forth between the anoxic zone and the aerobic zone. The mixed liquor is then transferred to a final clarifier where activated sludge is separated from purified supernatant. To increase the NO.sub.x.sup.- reducing enzymatic activity of denitrification microorganisms, the activated sludge is retained in the final clarifier for a time period sufficient to permit adaptation of these microorganisms to a nitrate/nitrite-respiring metabolic pathway.

Abstract: An automated wastewater treatment miniplant intended for installation and use with individual residences. Wastewater such as raw sewage is received in a settling tank to remove suspended solids, and then flows to an intermediate tank where the sewage is aerated and churned to promote aerobic treatment of organic materials in the sewage. When the wastewater in the intermediate tank reaches a predetermined level, a batch of that wastewater is transferred to an aerator-clarifier tank where further aerobic treatment of the batch wastewater occurs under controlled conditions, without dilution with incoming wastewater. Further aerobic decomposition of the wastewater takes place in the aerator-clarifier tank. Sludge is allowed to settle in that tank, and supernatant liquid within that tank is periodically withdrawn for dispersal in a drain field. Sludge is periodically returned to the intermediate tank to augment the biomass in that tank. Some sludge is periodically wasted from the system.

Abstract: In the aeration reactor described in the specification, an aeration basin has two aeration cells separated by a dividing curtain and connected in series so as to normally receive wastewater in the first aeration cell and then pass the wastewater to the second aeration cell which is followed by a clarifier to separate sludge from the treated wastewater. A liquid level detector in the reactor responds to surges in the rate of flow of the wastewater through the reactor to redirect incoming wastewater and return sludge from the first aeration cell into the second aeration cell and isolate the first aeration cell to preserve active sludge in that cell.

Abstract: A process and apparatus for biological purification of wastewater resulting in reduction of biological oxygen demand, reduction of suspended solids, and for nitrification, wherein the process involves aerating wastewater in a treatment zone for reduction of biological oxygen demand, transferring the mixed liquor from this treatment zone on an alternate basis to a second or third treatment zone which undergoes an aeration/settle, fill and decant cycle. As the second or third zone is receiving influent, it is being decanted in a modified plug-flow fashion. The alternate treatment zones allow for a continuous discharge of treated effluent during the process. During aeration of the second or third treatment zone, mixed liquor is recycled to the first treatment zone. Sludge is retained long enough to achieve nitrification. This invention is particularly suited for modification of aerated lagoon systems to achieve nitrification with a high degree of efficiency.

Abstract: This invention is directed to an activated sludge treatment process for removing phosphorus and nitrogen from wastewater. The process includes providing wastewater influent and activated sludge in a stressed contact zone to form a mixed liquor. In a luxury contact zone, the mixed liquor is mixed and aerated and the organisms in the activated sludge take up at least portion of the phosphorus. The method further includes separating the activated sludge from the mixed liquor, and returning at least a portion of the activated sludge to the stressed contact zone. The inventive process accomplishes wastewater treatment without having to pass the wastewater through an anaerobic zone.

Abstract: An apparatus for waste water treatment, wherein fluorine contained in waste water is treated into a fluoride through a chemical reaction and sludge containing the fluoride is thickened and dehydrated into a sludge cake, has first and second tanks each packed with calcium carbonate mineral. In the first tank, waster water containing fluorine is agitated by air discharged from an air diffuser and caused to react with the calcium carbonate mineral. Through this reaction of the waste water with the calcium carbonate mineral and action of microorganisms on the surface of the calcium carbonate mineral, a pH value and a fluorine concentration of the waste water is adjusted till the pH value and the fluorine concentration fall within their respective predetermined ranges.

Abstract: The present invention provides apparatus and method for increasing the wastewater treatment capacity of an existing pond treatment facility wherein the facility includes at least one treatment pond and means for bringing influent wastewater to the pond. Apparatus according to the present invention includes a porous baffle placed into the pond so as to separate the pond into two separate and distinct, but fluidly connected portions. The baffle thus divides the pond into a first portion for treatment of biological solids in the wastewater with the use of concentrated bacteriological growth and a second portion which provides a reservoir to accommodate high rates of wastewater flows and organic loads such as will occur with storm water flow.

Abstract: A combined aerobic and anaerobic treating method and facility for treating hog wastewater, in which, wastewater flows through six consecutive steps, namely: 1 raw wastewater tank 2 grit removal chamber 3 natural solid-liquid separation device 4 equalization basin 5 aeration tank and 6 final clarifier, and is effectively treated by way of microbiological technology, without adding any chemical precipitatant or coagulant, from highly polluted hog wastewater to qualified effluent for normal discharge. Not only can it help reduce river pollution, but also will be free from secondary pollution by adding chemical additives. An organic fertilizer, which can be directly utilized is a by product.

Abstract: A cyclical process for degrading waste organic matter to gaseous products and substantially zero volume of solid matter by subjecting the waste alternately and cyclically to stages of mesophilic and thermophilic digestion in which the organisms from one stage are inactivated and become a substrate for the organisms in the next stage, this inactivation resulting from a temperature shift. At the end of the cycle, solids are collected and returned to the first microbial digestion stage for recycling together with a fresh input of waste.

Abstract: A method of operating a sequencing batch reactor having a cycle consisting of FILL, REACT, SETTLE and DRAW periods and optionally an IDLE period, wherein supply of feed to the sequencing batch reactor comprises distributing the feed into settled sludge in the bottom part of the reactor. Also provided is a method of operating a sequencing batch reactor having the foregoing cycle, wherein the FILL and REACT periods include at least one non-mixed period.

Abstract: In a method and a device for sewage purification, sewage is purified by continuously passing it through several stages of treatment, wherein the passage of sewage is regulated by a process control device and is monitored by sensors. Treatment ensues in physical processing stages, pre-flotation stages, two-step biological clarification stages and one post-flotation stage. The pre-flotation stages as well as the biological clarification stages are each provided with gas-water mixers, and the pre-flotation stages, the biological clarification stages and the post-flotation stage are provided with solid foam separators having outlet channels. Clear water from a clear water overflow basin is supplied to the individual stages through the gas-water mixers and through a clear water return pipe. It is also possible to provide chemical treatment prior to biological clearing, to provide clear water recycling for additional treatment, and to provide solids treatment and a reduction stage.

Abstract: A continuous cyclic process for desulfurizing a petroleum liquid which contains organic sulfur molecules, a significant portion of which are comprised of sulfur-bearing heterocycles. This process involves oxygenating the petroleum liquid and treating it with a biocatalyst capable of catalyzing the sulfur-specific oxidative cleavage of organic carbon-sulfur bonds in sulfur-bearing aromatic heterocyclic molecules such as dibenzothiophene. a particularly preferred biocatalyst is a culture of mutant Rhodococcous rhodocrous bacteria, ATCC No. 53968. In the present process, the activity of this biocatalyst is regenerated; it can be used for many cycles of treatment. A system for conducting the continuous cyclic process of biocatalytic desulfurization of petroleum liquids is also disclosed.

Abstract: The specification discloses a process and apparatus for the purification of wastewater in several successive stages wherein the wastewater is aerated in a first region and is then subjected to intermediate clarification in a second region and including a post-clarification aeration in a third region and post-clarification sedimentation in a fourth region.In order to provide a simple, space-saving, low-cost yet reliable wastewater treatment arrangement, the apparatus is arranged to include all four regions in one basin by providing separating walls in the basin. These regions can be preceded by other processing stage regions and followed by filtering or storage regions.In order to allow adjustment for varying loads and for changing relationships between hydraulic and biochemical loads, the separating walls between the regions are arranged to be movable to permit changes in the relative volumes of the regions.

Abstract: In a two-stage activation plant, part of the activated sludge (sludge circuit (1)) from the first stage (11) is transferred to the second stage (12) and part of the activated sludge (sludge circuit (2)) from the second stage (12) is transferred to the first stage (11), so that mixed biocenoses are formed in both stages (11 and 12). The biomass to be denitrified from the first stage is transferred to the second stage by the sludge circuit (1) and the biomass to be nitrified from the second stage is transferred to the first stage by the sludge circuit (2), so that not only carbon compounds are decomposed but nitrogen compounds may be removed by nitrification and denitrification in both stages (11 and 12).

Abstract: A sequencing batch waste treatment facility with pretreatment mixing and equalization by mixing with selectively bred bacteria to achieve a selected waste to bacteria ratio, wherein waste is treated and reduced to acceptable biological oxygen demand levels for municipal-type waste treatment or general discharge per regulatory permit. A treatment colony of mature bacteria is cultivated and maintained in a treatment tank while a colony of young bacteria, separate from the treatment colony, is selectively bred in a bacteria tank to be particularly adapted to digest the waste being treated. Newly received waste is mixed to break macroscopic solid waste apart, into microscopic solid waste and to blend solid waste and liquid waste components into a waste slurry. Some of the selectively bred bacteria are portioned and mixed into the waste slurry up to an equalization point. The equalized batch of waste slurry is subsequently transferred to 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: 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).

Abstract: An activated sludge treatment process is disclosed wherein a sewage sludge component is fermented for a period of at least 15 days to form soluble carbonaceous substrates, the fermented sludge component is contacted with influent sewage to form a conditioned sewage, and the conditioned sewage is supplied to the activated sludge plant.

Abstract: A wastewater treatment system is provided which includes (a) two chambers in which microbiological cultures grow aerobically, a first chamber which receives wastewater to be treated and a second chamber which produces activated sludge; (b) a float sludge separator for removing from the system float sludge made with the aerobic culture from the first chamber; and (c) an activated sludge separator for separating activated sludge, which is settleable, and treated wastewater from the aerobic culture in the second chamber. In the system, one portion of the activated sludge from the activated sludge separator is fed to the first chamber, to seed culture growth there, and another portion of the activated sludge is recycled to the second chamber, to seed culture growth there.

Abstract: A wastewater treatment system and method is disclosed, including a circular aeration basin and a contiguous annular clarifier channel. Rotational flow of an aerated mixture of untreated wastewater and return sludge is induced in the aeration basin at its periphery with relatively less turbulent flow at the center.A clarifier inlet is fluidly connected to the aeration basin through openings provided in the aeration basin wall, the clarifier inlet including means to dissipate turbulence.A sludge removal manifold extends within the clarifier having valve-controlled suction arms. The spaced suction arms provide for precise control of sludge blanket depth and sludge age independent of rate of sludge return to the basin.Process sludge withdrawn from the clarifier is mixed with raw wastewater and returned to the aeration basin.The relatively less-turbulent flow in the central area of the basin allows process sludge to accumulate in said central area.