Abstract: The sewage lagoon system has a first pond containing mechanically and biologically degrading dissolved and undissolved organic and anorganic pollutant matter, without a recirculation of the forming activated sludge. The first pond is connected to a nitrification lagoon. It contains vertical contact beds for gathering nitrobacteria, which are horizontally flown through. The flow and the introduction of air in the nitrification lagoon are effected by air-water pumps generating a directed flow and provide the transversal flow through the contact beds. The circulation rate in the nitrification lagoon is at least 10 times the throughflow rate.

Abstract: The present invention relates to a process and apparatus for purifying waste gases by scrubbing with an adsorbent suspension. The adsorbent suspension in a concentration from 40 g/l to 200 g/l is here distributed uniformly or almost uniformly in at least one gas-scrubbing device, passed through at least one ordered mass transfer zone and contacted with the gas and then passed into at least one separately arranged reactor, the biologically degradable or convertible impurities are reacted, with the additional use of aerobic bacteria and oxygen, with forced motion and the purified liquid or suspension is recycled, wholly or as part stream, to the gas-scrubbing device, distributed therein and contacted again with the gas which is to be purified.

Abstract: Wastewater containing impurities refractory to secondary treatment is first introducted into an aerobic biological treatment stage operating with an oxygen-enriched stream and subsequently into a precipitation stage where the biologically treated wastewater is combined with Ca(OH).sub.2 to precipitate Ca(OH).sub.2 CaCO.sub.3 sludge which adsorbs or occludes impurities. The clear liquid, separated from the resultant sludge, is passed to a second precipitation stage where it reacts with a CO.sub.2 and oxygen-containing waste gas at least in part from the aerobic biological treatment stage, thereby forming additional CaCO.sub.3. Waste gas withdrawn from the second precipitation stage, being enriched in oxygen is recycled to the aerobic biological treatment stage.

Abstract: The invention relates to a method and apparatus for treating waste material mass in a reactor comprising gas distribution members (2, 22), heating members (4, 23) and mixing members (6, 25) for the waste material mass, as well as a waste mass feed member (9, 31) and discharge opening (11, 34). According to the invention, the decomposition of the waste mass is intensified by heating the mass by means of the heating members (4, 23) connected to the gas distribution members (2, 22), by conducting gas onto the surfaces of the heating members (4, 23).

Abstract: A process and apparatus for biological purification of waste water wherein waste water and oxygenated gas are introduced into a reactor using ascending cocurrents. The reactor is equipped with a lower fluidized bed and an upper fixed bed for filtration. The particles in the beds are composed of expanded materials having a density less than 1. The particles in the fixed bed are both smaller and lighter than those of the fluidized bed.

Abstract: An activated sludge sewage treatment process wherein sewage is received into a sewage treating basin in first zone into which activated sludge is mixed and retained for a period sufficient to form a non-bulking sludge and absorb biodegradable dissolved compounds into the activated sludge, and aerated and subjected to a quiescent condition to permit settling of the sludge in a zone characterized in that it has less than approximately twenty percent of the biochemical oxygen demand of the original sewage and where in the sludge is non-bulking, decanting treated sewage from the upper portion of the basin after allowing the sludge to settle, and cyclically repeating the process, anaerobically fermenting the influent sewage, and recycling anaerobically fermented partially treated sewage to the input of the influent sewage is disclosed.

Abstract: A process for treating organic waste water in which a first step provided the stage precedent to a second step using an aerobic filter bed employs an upward flow type solid-liquid separator packed with a filter medium, with the SS (suspended solids) removal at the preceding stage being performed at a high SS removal rate and in a short time.

Abstract: A two-step process for microbiological purification of contaminated water, comprising a first step using anaerobic conditions in a reactor having a stationary bed and a biofilm fixed thereon followed by conventional microbiological purification, characterized in that in said first step the water is supplied at the upper end of the reactor and is brought to trickle over the fixed biofilm without drenching the bed and while maintaining a continuous gasphase within the bed.

Abstract: Wastewater and recycled activated sludge are homogeneously mixed in a first aeration zone by injecting an oxygen-containing gas such as air into the lower portion of the zone under conditions which produce a complete mix reaction and sufficient oxygen is supplied to meet the biological oxygen demands of the mixed liquor. The gas is introduced, preferably by a plurality of fine bubble membrane diffusers, in the form of fine bubbles having a diameter less than about 4 mm. The bubbles provide both the mixing to keep solids in suspension and the oxygen required to maintain the overall dissolved oxygen content in the first aeration zone as close to 0 as possible. The mixed liquor is sequentially contacted with an oxygen-containing gas in second and third aeration zones under conditions which produce a complete mix reaction, preferably by fine bubble membrane diffusers, clarified and a portion of the settled sludge is recycled to the first aeration zone.

Abstract: A process for the treatment of wastewaters heavily polluted by fats, proteins and/or carbohydrates of vegetable or animal origin or their processing products by degradation by microorganisms in a continuous flow reactor without separation of fats and/or sludges, comprising passing the wastewasters through a first part of a reactor containing aerobic and anaerobic microorganisms to consume the free oxygen present in the water, with at least partial degradation of the pollutants to fermentation products, and on flowing through another, adjoining part of the reactor, the fermentation products and any pollutants still present are coverted in the presence of the anaerobic microorganisms into--predominantly--digester gas and biomass. Optionally, fertilizing and/or pH-stabilizing substances or other auxiliaries are added in order to reduce the susceptibility of the system to failure.

Abstract: An improved method and apparatus for treating a biodegradable organic material in an aqueous medium to produce methane gas is disclosed. The method involves flowing the aqueous medium under pressure through a hydrolytic-redox, immobilized microbe bioreactor to form a reaction product and then continuing the flow of the reaction product through an anaerobic, immobilized microbe bioreactor whereby methane gas is evolved. The aqueous medium is flowed in a downward direction counter to the flow of the gaseous carbon dioxide given off during the reaction and the aqueous medium may be recycled.

Abstract: A method of treating raw water containing phosphorous and nitrogen compounds and organic matter in which the raw water is passed through an aerobic zone containing a porous material. Anaerobic treatment is carried out in the presence of a hydrogen donor. The porous material is tobermorite and/or xonotlite with a porosity of 50% to 90% and is produced by foaming and hardening a silica-based material, a lime-based material and water, and subjecting the porous material to hydrothermal synthesis. The order of the aerobic and anaerobic treatments may be varied.

Abstract: An apparatus for sludge thickening including a sludge thickener allowing suspended solids of sludge supplied thereto to settle by their own weight while being thickened. The sludge supplied to the sludge thickener is subjected to aeration for a predetermined period of time in a sludge aerator. Aeration of the sludge strips the anaerobic gas, which is attached to the suspended solids in the form of bubbles or dissolved in the sludge, to atmosphere. By aeration of the sludge before being fed to the sludge thickener, floating of the thickened sludge in the thickener can be avoided.

Abstract: A method for the substantial separation of at least one gas component from a gas mixture to generate a residue gas substantially depleted of the gas components to be separated. A semipermeable membrane is provided which has a feed gas side and a sweep gas side. The feed gas side is contacted with a feed gas mixture containing at least one gas to be retained and at least one gas to be separated therefrom. The sweep side is simultaneously contacted with a sweep gas having a pressure lower than that of the feed gas. The partial pressure of certain gas components present on both sides of the membrane are balanced to cause the remaining gas components to diffuse in either direction across the membrane depending upon their differential partial pressures. Apparatus for the gas separation is also provided.

Abstract: A dispersion of air or oxygen in liquid sewage and/or or sludge is admitted tangentially into the lower portion of an upright vessel wherein the dispersion rises and is compelled to flow through eccentric flow restricting passages in several superimposed horizontal partitions so that the dispersion is repeatedly induced to form a turbulent helical flow. The rising dispersion flows around a tube which returns a portion of the dispersion into the lower part of the vessel and causes the remaining portion to overflow into a receptacle having an outlet at a level below the open top of the tube. The dispersion which descends in the tube is readmitted tangentially into one or more chambers which are separated from each other by the partitions in the vessel and communicate with each other by way of the respective flow restricting passages.

Abstract: In a sludge thickener, supernatant fluid is drawn off via peripheral ducts and oxygenated at a suitable location. The supernatant fluid is thereafter reintroduced into the thickener via diffusers distributed transversely of the thickener and intermediate the peripheral ducts. The generation of nauseating smells is thereby prevented, and an advantageous increase of the concentration of the sludges is attained.

Abstract: The invention relates to a method for producing a product from which compost can be suitably produced and which contains sludge obtained from a sewage purification process, in which method the sludge is mixed in a fluid state with a finely-divided carbon-carrier selected from the group sawdust, peat and bark, and with polyelectrolyte, and is then mechanically dewatered to a dry substance content of at least about 28 percent by weight.

Abstract: A method and apparatus for increasing the capacity of an activated sludge wastewater treatment plant which utilizes microscreens in conjunction with rotating biological contactors that are placed in the primary settling tank, the aeration tank and the final clarification tank. A rotatable microscreen is placed upstream of the primary settling tank and downstream of the final clarification tank. The result is a more efficient and less energy consuming system which reduces the organic loads. Preferably, the microscreening preceding the biological treatment stage will have a mesh size in the range of about 50-200 mesh and the microscreen placed after the biological treatment stage will have a mesh size in the range of 6-44 microns. Additional benefits are obtained in recycling the treated water which is passed through the rotating biological contactor as well as utilizing it to aid in rotating the contactor.

Abstract: The invention provides a process for the performance and control of chemical or biochemical process cycles in two or a plurality of series-connected reaction stages or basins, with which gassing of a fluid is controllable. The process provides for a recirculation of the fluid between reaction stages or basins in that the basins are preferably arranged concentrically to one another, can be charged selectively, and have at least one connection between one another through which the fluid passes so that the contents of the basins are caused to assume a horizontal rotational flow. Recirculation of the fluid is provided by overflow dams, wall openings, or other devices.

Abstract: A method and an apparatus for dissolving gas in a body of sewage comprising providing a skirt member having a lower open end extending upwardly from said body of sewage to define a volume of said sewage separate from an adjacent body of clarified liquid in said tank, removing a flow of sewage from said body of sewage and pressuring said flow, introducing oxygen into said pressurized flow to form a mixture of oxygen and sewage, introducing said mixture as a jet downwardly into the inlet of a chamber disposed in said volume defined by said skirt member to induce sewage in said chamber and thereby oxygenate said sewage, discharging said oxygenated sewage downwardly through an outlet of said chamber at a reduced velocity, and reducing the momentum of said discharged oxygenated sewage by directing the same onto baffles spaced from the outlet of said chamber.

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: This invention provides a method for treating wastewater by circulating wastewater around a system comprising a downcomer and a riser which communicate directly at their lower ends, the level of the wastewater in the downcomer being maintained above the level of the wastewater in the riser to provide a hydrostatic pressure head which causes circulation of the wastewater around the system, supplying a gas containing oxygen to the wastewater as it passes through the downcomer, pumping the wastewater from the top of the riser back into the top of the downcomer and removing treated wastewater from the riser at the same rate as wastewater is introduced into the system characterized in that the height of the hydrostatic pressure head is controlled by adjusting the height at which treated wastewater is removed from the riser and the level of the wastewater in the riser. The invention also provides an apparatus for putting the method into practice.

Abstract: In purification of a liquid waste, the liquid waste material is introduced into a sedimentation tank, and the relatively heavy material settles within the tank and is converted into a sludge through anaerobic activity. The supernatant foul liquid waste from the sedimentation tank is introduced into a submerged bioaeration-beds tank, and the supernatant foul liquid waste descends to successively flow between a plurality of irrigated sheets positioned in superimposed spaced relation within the bioaeration-beds tank. The liquid waste from the bottom of the bioaeration-beds tank is returned to the upper region thereof by an oxygen-containing medium, and the returned liquid waste and the supernatant foul liquid waste descend together and successively flow between the irrigated sheets, whereby the downwardly flowing foul liquid waste is purified by the activity of aerobic micro-organisms in biomembranes formed on both sides of the irrigated sheets, the purified liquid being recovered from the bioaeration-beds tank.

Abstract: A process for simultaneously converting swine, poultry and cattle wastes to useful products comprising combining said wastes with water to form a slurry, removing feathers and grit from said slurry, subjecting said slurry to anaerobic fermentation for a period of time to produce a methane-containing gas stream and a slurry containing a partially fermented solid residue, separating the methane-containing gas stream from the slurry, separating partially fermented solid residue from the slurry and drying the partially fermented solid residue to form a feed product therefrom. The quantitative ratio of cattle wastes containing cellulosic or fibrous materials to the poultry and swine wastes containing more rapidly fermentable materials is controlled to thereby control the pH of the slurry during anaerobic fermentation. At least a portion of the methane-containing gas stream produced is utilized as fuel for carrying out the drying step.

Abstract: A method and apparatus for the treatment of wastewater in which the wastewater is circulated around a system comprising a downcomer and a riser communicating with each other at their lower ends, the level of the wasterwater in the downcomer being maintained above the level of the wastewater in the riser and providing a hydrostatic pressure head which causes circulation of the wastewater around the system at a pre-selected rate, a gas containing free oxygen is supplied to the wastewater as it passes through the downcomer, and the wastewater is pumped from, or form near, the top of the riser back into the downcomer (or vessel communicating therewith) at a position(s) above the highest level to which the wastewater in the downcomer can fluctuate during normal operation of the system when operating at maximum load.

Abstract: A biological waste water treatment carried out in a single tank. The conditions in the tank are controlled to provide a biological reaction zone containing waste water and biodegrading organisms and an overlying clarification zone from which an effluent of treated waste water flows. The recycle stream is continuously withdrawn from the biological reaction zone, supplemented with influent waste water, passed through an oxygen-dissolving device, and the supplemented stream returned to the reaction zone. The oxygen is monitored and supplied to satisfy the demands of the organisms and, at the same time, to keep the oxygen in solution. According to the invention, the supplemented recycle stream is continuously injected along the bottom of the biological reaction zone in a horizontal shallow inflow having a width substantially greater than its depth and a flow considerably greater than that of the influent.

Abstract: A method and apparatus is provided whereby a pressurized long vertical shaft bioreactor is protected against extreme surges of influent waste liquid. The method provides for the transfer of excess waste from the top of the bioreactor head tank to an adjacent collection vessel where, in response to the pressure created in the bioreactor, the collected waste is caused to overflow and is returned to the influent waste stream. The method permits the return of waste from the reactor to the influent stream while bypassing the normal circulation route through the reactor. Simplification of control is provided and float or level control valves may be eliminated thereby reducing construction, operating and maintenance costs.

Abstract: A process is provided for the biological treatment of aqueous waste in a pure oxygen activated sludge/ozone disinfection system as well as apparatus to accomplish the process.In this process, the off-gas from an ozone disinfection tank, after removal of residual ozone, is blended with the pure oxygen stream needed to supply the requirements of activated sludge treatment basin and ozonation zone. This blending of two streams is carried out either in pipe line or in a specially built (and baffled) vessel. The combined stream is then compressed and split into two portions. One portion of the gas is diverted to the activated sludge treatment plant. The rest of the gas is dried to a dew point level and then fed to ozone generator. The discharge from the ozone generator contains a small percentage of ozone and is routed to the ozone disinfection tank. An alternate of the system, compresses the off-gas first and then combines it with pure oxygen stream.

Abstract: A process for digestion of sludge wherein the sludge is oxygenated in a first digestion zone at temperature of from 35.degree. to 75.degree. C. to partially reduce the biodegradable volatile suspended solids content of the sludge. The partially stabilized sludge is anaerobically digested in a covered second digestion zone at temperature of from 25.degree. to 60.degree. C. to further reduce the biodegradable volatile suspended solids content of the sludge, to less than about 40% of the biodegradable volatile suspended solids content of the sludge introduced to the first digestion zone.