Abstract: Liquid to be treated flows into a combined sedimentation and thickening tank. The upper part of this tank is a sedimentation zone in which the liquid passes through parallel flow paths between downwardly inclined separator plates below which the solids fall to the bottom of the tank into the thickening zone whereat the solids are stirred and removed by a suitable stirring and scraping device. The liquids flowing with the solids through the parallel paths are removed at the end of said paths and delivered directly to the top of the sedimentation zone thus leaving the thickening zone essentially flow-free. Flocculants may be added to the water to be treated in a separate flocculation compartment arranged upstream from the sedimentation compartment. A separate destabilization compartment may be provided upstream from the flocculation compartment. A square sedimentation zone may merge smoothly into a circular thickening zone. The thickening zone may extend beneath the flocculation compartment for compactness.

Abstract: Activated sludge treatment system for removal of pretreatment BOD and nitrogen values from waste water, utilizing a mixed liquor tank comprising a nitrate cracking channel zone, a denitrification channel zone and an aeration zone in specified relationship and adapted to provide specified operating conditions in the respective zones.

Abstract: The following disclosure teaches ways and means for clarifying raw sewage and thickening secondary sewage sludge. The disclosed apparatus comprises a tank having upper and lower feedwells disposed therein. Raw sewage is introduced into the lower feedwell and flows into the lower part of the tank to be clarified therein, and secondary sludge is aerated and introduced into the upper feedwell so that it flows therefrom and thickens in the upper part of the tank by flotation type thickening.

Abstract: The present disclosure is directed to a sewage treatment device of the marine type and operates on an extended aeration principle employing an aerator, clarifier and disinfector. The clarifier is disposed beneath the aerator and the top of the clarifier with a common wall therebetween which forms the bottom of the aerator. A first passage conducts fluid from the aerator to the clarifier and has a central port in the common wall. A second passage conducts fluid from the clarifier to the disinfector. The aerator has an influent inlet and the disinfector has an effluent outlet.The treator includes in the aerator vessel nozzle means for admitting air to the vessel in a direction to cause fluid in the vessel to move orbitally about a vertical axis with the nozzle means being disposed at a level proximate the common wall between the aerator and clarifier.

Abstract: The invention is an improved controlled natural purification system for an advanced wastewater treatment and protein conversion and recovery. The system provides for treating municipal wastewater and associated organic industrial discharges anaerobically and aerobically. The system consists of such treatments in a tank complex where the waste organics are reduced to inorganic forms available for microalgae culture in tanks uniquely designed for rapid growth. The system includes a recovery mechanism to recover the algae for food purposes. Utilizing organic wastewater as the renewable resource, the system has the potential to develop from a wastewater treatment process that removes excess nutrients, producing reusable water and a commercially valuable algal by-product, to large scale algae farming cost-effectively producing millions of tons per year of sterile, stable, high protein algal foodstuff.

Abstract: Device for compacting fluid sludges containing fibrous materials, consisting in slowly stirring the sludge mechanically in the top part of a device, then pressing it moderately in a conical intermediate part of the device and then compacting it in a bottom cylindrical chamber of the device.

Abstract: Production fluid from a well and emulsion breaking chemicals enter a settling vessel where much of the fluid separates into distinct levels by gravity with water at the bottom, an oil-water emulsion above the water, oil-with-emulsion above the emulsion, and gas above the oil-with-emulsion. The oil with the emulsion has two to five percent emulsion in it. The oil-with-emulsion flows over a weir into a weir box and then into the inlet of a centrifugal, pitot separator which breaks the emulsion contained in the oil by the action of a centrifugal force field to produce distinct streams of oil and water. The water feeds back into the vessel and the oil goes to storage. In the event that the emulsion feed to the separator is insufficient, the oil-with-emulsion level in the weir box falls and oil recirculates from the separator into the vessel to raise the level of oil-with-emulsion. Water leaves the vessel as required to maintain an appropriate water-emulsion interface level.

Abstract: Processes are provided for accomplishing wet oxidation using a reaction zone wherein the gas phase (oxygen) is allowed to pass therethrough at a flow rate independent of the liquid phase (waste water) flow rate so that more oxygen can be supplied to a given volume of waste water than is possible for a conventional reactor of the equivalent size. A high efficiency wet oxidation is provided by which the process technology can be practiced either in a single stage or multistage. The reactor is directed to operate at temperatures ranging from about 350.degree. to 600.degree. F. at pressures ranging from about 800 to 2200 psig and the reactor provides a gas phase/liquid phase separation feature.

Abstract: A process and apparatus for the treatment of aqueous waste materials or effluents, particularly the aqueous waste materials of bottling plants and installations, in which a trickling element is employed for the basic rough processing to effect the removal of biological oxygen demand (BOD). The discharge stream of effluent from the trickling element is conveyed into an oxidation-reaction tank, providing for the chemical oxidation of light organic floc resulting from biological action in the trickling element and further BOD reduction, and for the oxidation of any biomass sloughing off the media in the trickling element. The treated waste material or effluent discharge emanating from the oxidation-reaction tank is conducted through a mixing tank which is adapted to simultaneously receive the final rinse waste effluent from the bottling plant, and to intermix the two effluents and subject these to further oxidation treatment through the intermediary of admixing air therewith.

Abstract: Sewage sludge and municipal solid waste are simultaneously processed by first dissolving a catalyst, such as sodium aluminate, in the sludge, then mixing the sludge-aluminate mixture with the municipal waste to form a carbonizing mixture. After dewatering and drying, the mixture is carbonized in a furnace heated by a mixture of city gas and pyrolysis gases given off by the furnace.

Abstract: A waste treatment apparatus operated either by gravity or by positive displacement pump in which a variable inflow of contaminated liquid is aerated, clarified, and filtered. The filtered liquid is used to backwash one of at least a pair of rapid sand filters, while the other rapid sand filter is being utilized. The alternating cycle of backwashing and filtering by the respective rapid sand filters, all of which is integrated with overall filtering operation, insures that at least one filter is fully operative at any time.The apparatus is adapted for variable inflow and can adapt to such unfavorable exigencies as overtaxing inflow and clogging at the rapid sand filter or at an earlier stage of contaminated liquid treatment. Sensors are located suitably throughout the apparatus to adjust the system to overflow conditions or clogged conditions, and the flows can be redirected through a preferred stage.

Abstract: A selfcontained apparatus for on-site renovation of sanitary waters comprises of three aeration chambers, a mineral storage and dispensing container, a submerged suspended solids separator located in the third aeration chamber, a flow equalizer, a chemical oxidizing agent dispensing system, a chemical oxidation-clarification chamber and a charcoal containing chamber, all enclosed in a single tank designed for use on land as a single or multiple family wastewater renovation system, or off-shore as a marine sanitation device.

Abstract: The present invention relates to a biological sewage treatment plant designed for the treatment of sewage by means of the active sediment method. The sewage treatment plant consists of a tank in the shape of a cylinder, wherein the concentric biosorption, biostabilization and settling chambers formed by vertical stationary screens coupled with each other are accommodated. The said chambers are divided into the internal and external sections formed by annular movable screens, connected to the rotary construction located above the tank. In the above mentioned construction there are suspended turbine aerators and aerating brushes. The movable screens are provided with floats with variable dipping depth consisting of vertical containers connected at a top with the gas supply pipe and, at the bottom, provided with suitable holes. The movable and stationary screens have ribs, wings and blades.

Abstract: A self-contained apparatus for on-site renovation of sanitary waters comprises of three bioreaction chambers, a mineral storage and dispensing container, a submerged suspended solids separator located in the third bioreaction chamber, a flow equalizer, a chemical oxidizing agent dispensing system, a chemical oxidation-clarification chamber and a charcoal containing chamber, all enclosed in a single tank designed for use as on-site single or multiple family waste water renovation system.

Abstract: Treatment plant for treating a fluid formed by waters and sludges and comprising a decanting system; a first centrifuging system for separating, on the one hand, the spent waters and, on the other hand, the sludges formed by organic compounds containing or not heavy metals and the sludges formed by higher-density mineral compounds; an irradiation device for irradiating, by means of an accelerated electron beam for example, the sludges formed by organic compounds and especially those containing heavy metals so as to convert them into mineral compounds which are less toxic and have a high density; a second centrifuging system for subsequently separating and eliminating these mineral compounds.

Abstract: Apparatus for the treatment of wastewater has an enclosed unit providing a facultative zone wherein a mixture low in dissolved carbon comprising raw sewage and partially processed sewage undergoes denitrification brought about by faculative organisms contained in the prevailing low oxygen environment. Effluent from the facultative zone is charged into an enclosed columnar oxidation unit where a controlled flow of air or oxygen oxidizes nitrogen compounds present in raw sewage into nitrates. Part of the effluent from this columnar oxidation unit wherein the limited flow of oxygen has been mostly consumed in oxidizing the nitrogen compounds and is low in dissolved oxygen is recycled to the facultative zone and part flows into a columnar denitrification zone wherein anaerobic microorganisms substantially completely remove nitrogen as gas from the nitrates producing an effluent with a low nitrate content. Columnar oxidation units and denitrification units are in essentially deep-bed filters.

Abstract: Effluent to be biologically purified is poured serially through three interconnected tanks with the first two tanks acting as activation tanks and the last tank acting as a post-clarification tank. After the concentration of activated sludge in the first tank has dropped to a predetermined value, the flow through the tanks is reversed so that the last tank, previously the post clarification tank, acts as one of the activation tank and the first tank, previously one of the activation tank, acts as the post clarification tank, while the middle tank continues to operate as the other of the activation tanks.In one embodiment, an aerator is provided in each tank and the aerators in the first and last tanks are switched on or off depending upon the direction of flow of effluent. In another embodiment, two movable aerators are provided and are disposed in use, in those tanks which are acting for the time being as activation tanks.

Abstract: The following disclosure teaches means for thickening primary and secondary sewage sludge. The disclosed apparatus comprises a tank having upper and lower feedwells disposed therein. Primary sludge is introduced into the lower feedwell and flows into the lower part of the tank to thicken therein. Secondary sludge is aerated and introduced into the upper feedwell so that it flows therefrom and thickens in the upper part of the tank by flotation type thickening.

Abstract: A method for separating components suspended in a liquid, in which a gas-liquid mixture is pressurised, and then is depressurised just before being introduced in a separation device so as to obtain a substantially colloidal gas bubble mixture, the gas bubbles adhering to particles of the suspended components which are made flotating thereby, the device for executing this method comprising a liquid compression pump, a relief valve, and a nozzle opening into the separation device just behind this nozzle.

Abstract: A novel mobile system for cleaning and processing catch basin and/or lagoon waste products is described wherein the degree of waste product dilution is carefully controlled prior to transmission to mobile dewatering truck capable of producing a substantially dry land fill suitable end product and water suitable for recirculation or environmentally acceptable discharge to a process head or sanitary sewer.

Abstract: A novel mobile system for cleaning and processing catch basin and/or lagoon waste products is described wherein the degree of waste product dilution is carefully controlled prior to transmission to a mobile dewatering truck. The truck comprises dewatering apparatus which is uniquely controlled to produce a substantially dry land fill suitable end product and water suitable for recirculation or environmentally acceptable discharge to a process head or sanitary sewer.

Abstract: Methods and apparatus for treating water/wastewater to remove grit, susped and colloidal solids of organic and inorganic nature, microorganisms and surfactants. Dense suspended solids (grit) are first removed by a centrifugation process. The influent water/wastewater is then passed through coagulation and flocculation chambers, an upflow clarifier and a high-rate settling chamber for final sedimentation. Next, the influent passes through a foam filter to remove colloidal particles. The water/wastewater under treatment is then pressurized and saturated with air and subsequently depressurized, causing the dissolved gas to bubble out of solution floating out suspended contaminants. At this point, ozone is introduced into the influent to create a thicker, more dense foam by oxidizing organic matter and for disinfection purposes. The foam floated to the surface of the influent is scraped off and furnishes the foam for the foam filter.

Abstract: Liquid to be treated flows into a combined sedimentation and thickening tank. The upper part of this tank is a sedimentation zone in which the liquid passes through parallel flow paths between downwardly inclined separator plates below which the solids fall to the bottom of the tank into the thickening zone whereat the solids are stirred and removed by a suitable stirring and scraping device. The liquids flowing with the solids through the parallel paths are removed at the end of said paths and delivered directly to the top of the sedimentation zone thus leaving the thickening zone essentially flow-free. Flocculants may be added to the water to be treated in a separate flocculation compartment arranged upstream from the sedimentation compartment. A separate destabilization compartment may be provided upstream from the flocculation compartment. A square sedimentation zone may merge smoothly into a circular thickening zone. The thickening zone may extend beneath the flocculation compartment for compactness.

Abstract: Apparatus for collection and removal of settled solids from the bottom part of a sedimentation zone, comprising a scraper blade attached to a bridge and drawn reciprocatingly and repetitively in a longitudinal path along the sedimentation zone. Means are provided whereby the scraper blade is drawn toward the end walls of the sedimentation zone for transverse alignment therewith at the approach of the bridge to the end walls, so as to eliminate solids accumulation adjacent thereto.

Abstract: Apparatus for collection and removal of settled solids from the bottom part of a sedimentation zone, comprising a scraper blade attached to a bridge and drawn reciprocatingly and repetitively in a longitudinal path along the sedimentation zone. Means are provided whereby the scraper blade is drawn toward the end walls of the sedimentation zone for transverse alignment therewith at the approach of the bridge to the end walls, so as to eliminate solids accumulation adjacent thereto.

Abstract: An improved technique for reprocessing, through a reaction zone, a portion of an agitated flow of waste water that is coupled into a wedge-shaped or frusto-conical separating zone via such reaction zone is described. A recirculation conduit, independent of an inlet aperture at the bottom of the separating zone for admitting an upward flow of water from the separating zone, has an inlet end communicating with the separating zone at an upper region thereof, the outlet of the recirculation zone emptying into the agitated water stream in the reaction zone. The inlet aperture at the bottom of the separating zone has a cross-sectional area which is small relative to the cross-sectional area of the separating zone and small relative to the cross-sectional area of the reaction zone.

Abstract: An apparatus to transform raw sewage into a substantially colorless and odor free effluent by the alternate action of aerobic and anaerobic bacteria as the sewage flows through a primary chamber and a secondary chamber to a settling chamber and finally to a holding tank from which the effluent discharges to a disposal area.

Abstract: A sewage treatment system is divided into two stages with a collection system dispersed therebetween. The first stage includes anoxic treatment units producing an anaerobic effluent which is moved through the vacuum tight collection system to the second stage of treatment including an oxidation unit producing an aerobic effluent containing nitrates, dissolved oxygen and activated sludge. The two liquids are mixed in a chamber and are subjected to treatment before discharge for producing a highly treated effluent from which a major part of the nutrients have been removed.

Abstract: Disclosed herein is a system for chemically treating a waste water including a storage tank, a reaction tank, and a pump for transferring the waste water from the storage tank to the reaction tank. Conduits connecting the pump to the tank and control valves controlling the flow through the conduits are arranged so that, by coordinated actuation of the valves, the pump recirculates the waste water through the reaction tank to provide intermixing of the treatment chemicals and discharges the waste water from the reaction tank after treatment. The chemical reagents are introduced into the system on the suction of the pump so that gravity feed or separate pumping means is not required for the reagents. The tanks are preferably circular and mounted in a spaced relationship on a common base forming the bottoms thereof.

Abstract: A method and apparatus for treating liquid sewage as effluent with oxygen-containing gas. The liquid is circulated firstly through a tubular compression coil which is rotated about a vertical axis, and secondly through a tubular decompression coil which is also rotated about a vertical axis. The oxygen-containing gas is supplied to the liquid as it passes through the compression coil.

Abstract: Apparatus for draining of muddy liquids, especially of sludges and slurries in sewage clarification plants, where first of all an ionic coagulant, eg., an anionic or cationic coagulating agent, is added to the muddy liquid in a first ionic coagulating means to obtain an aqueous sludge which is separated from the muddy liquid in a first coagulating chamber by sedimentation in a straining zone and wherein the aqueous sludge is subsequently filtered and pressed, whereafter the liquid is treated in a second coagulating or mixing chamber.The apparatus to carry out the process comprises in addition to the first coagulation chamber coagulation chamber for the muddy liquid, a revolving screening belt constituting the filtering means for the straining zone and a series connected revolving screen belt press which aids in dewatering the filtered solids.

Abstract: Apparatus in which contaminants from the raw or waste waters are removed by combined biological-chemical degradation of such contaminants comprises first, second and third chambers. An aeration zone is provided in the first chamber. A slanted plate is located in the second chamber to define an aeration zone which overlies a sludge separation zone. Means for transferring such waters from the equalization zone to the upper region of the aeration zone is provided. The slanted plate provides for a downflow of waters through the aeration zone and an upflow of waters through the sludge separation zone, where due to the lower end of the slanted plate being spaced from the lower portion of the second chamber wall forms a constriction to the flow of waters to increase the rate of flow and form a fluidized bed of active media in the sludge separation zone.

Abstract: An apparatus for treatment of sewage and waste materials, and while applicable to larger installations, is particularly desirable for relatively small, for example family and multi-family installations, utilizing high rate bio-chemical oxidation/physio-chemical adsorption, in which the sewage is subjected to a primary biological treatment, and a secondary settling treatment, with the primary-secondary effluent, following addition thereto of an organic-inorganic chemical material comprising prereacted floc, a phosphate precipitating material and a nonionic polyelectrolyte, operative to maintain pH and zeta potential favorable to floccuation, being subjected to a tertiary treatment by passage through a mixed filtration and adsorption bed containing activated carbon, the mixed bed being periodically regenerated by a partial wet-gas oxygenation cycle, utilizing a reflex operation in which the products of regeneration are returned to the primary treatment, and in which the final effluent may, for example, contain

Abstract: A method for removing mercury from water contaminated with mercury comprising contacting water containing metallic mercury with finely divided anthracite coal. The mercury laden water can be first treated with sodium borohydride to reduce dissolved mercury to the metallic form. The water treated with reducing agent, is filtered through a pressure leaf filter coated with a filter aid, contacted with anthracite coal and contacted with chelating resin.

Abstract: The following disclosure teaches means for thickening primary and secondary sewage sludge. The disclosed apparatus comprises a tank having upper and lower feedwells disposed therein. Primary sludge is introduced into the lower feedwell and flows into the lower part of the tank to thicken therein. Secondary sludge is aerated under super atmospheric pressure and introduced into the upper feedwell so that it flows therefrom and thickens in the uppper part of the tank by flotation type thickening.

Abstract: An integrated system for treating wastewater containing biodegradeable organic contaminants by oxygenation thereof in the presence of activated sludge in an enclosed oxygenation zone with at least 50% oxygen feed gas and removal of the residual organic contaminants by adsorption in an activated carbon adsorption zone. At least part of the oxygen-depleted vent gas discharged from the oxygenation zone is concurrently flowed upwardly through the adsorption zone with the oxygenated effluent to maintain aerobic biological conditions in the adsorption zone for physical adsorption and biochemical oxidization of the residual organic contaminants therein.

Abstract: A sewage purification system for purifying liquid sewage containing biologically degradable solid waste material. The sewage is subjected to successive treatment steps in three basic consecutive stages during which the sewage is agitated to break up the solid waste material and encourage the proliferation of microorganisms for the digestion thereof, settled to effect separation of the purified liquid component from the residual solid waste material in suspension component with recycling of the latter, and thereafter distributed into the ground.

Abstract: A housing has an interior casing receiving a coolant. This casing is associated with a forced cooling system and has open ended tubular portions therethrough formed of electrically conducting metal. Glass ozone generating tubes are removably supported in the tubular portions by axial movement and are held in spaced ozone generating position by spacers on the tubes. The tubes have an electrically conducting silver coating on the interior surface and have an interior band engageable with the coating for admitting high voltage to the tube from a conductor leading into the tube. A treatment tank associated with the ozone generating system has a recirculating conduit operably connected with the housing for the ozone generating tubes. An additional conduit extends from the treatment tank to a storage tank and a filter for filtering out coagulated material is provided in this conduit.

Abstract: A novel mobile system for cleaning and processing catch basin and/or lagoon waste products is described wherein the degree of waste product dilution is carefully controlled prior to transmission to a mobile dewatering truck capable of producing a substantially dry land fill suitable end product and water suitable for recirculation or environmentally acceptable discharge to a process head or sanitary sewer.

Abstract: A combined dialyzer and adsorber unit in one disposable package. The dialyzer is integral with the adsorber which contains a chemical adsorbent to regenerate a dialysate solution. In a preferred embodiment the dialyzer is mounted in the form of a sleeve around the adsorber container as a core. Dialysate is introduced into the dialyzer, then immediately circulated through the chemical adsorbent contained in the adsorber. There the major components of the impurities dialyzed out from the dialyzer can be adsorbed, whereby the dialysate is regenerated. The sleeve can be the adsorber and the core the dialyzer. In addition, the adsorber can have included therein, either mixed in with the adsorbent material or in a separate compartment, a water soluble dialysate material which can be dissolved by circulating water through the unit prior to starting to dialyze the patient.

Abstract: A process and apparatus for decreasing the phosphorus content of waste water by means of contacting the waste water with the products of aqueous reaction with elemental iron, preferably subjecting the mixture to sequential aerobic and anaerobic conditions, and concentration of the suspended solids fraction which contains the major portion of the influent phosphorus in solid stable form, and separating the relatively clear liquid fraction therefrom.Contacting the waste water with products of the aqueous reaction with elemental iron may be brought about by recycling at least part of the separated solids through at least part of the process.

Abstract: A mixing chamber for thickening sludge, especially sludges in a sewage clarification plant by means of a flocculation agent in combination with an overflow drainage means wherein the sewage feed to the bottom of the mixing chamber enters a mixing zone and flows upwardly into an overflow at the top and out through a diversion means for the thickened sludge leading to a sedimentation belt or to a press filter, handling to the outside of the mixing chamber. The top of the mixing zone is widened by means of a flow section for the thickened sludge which is formed by dewatering through the perforated screen walls and the waste water is disposed downstream of the agitated mixing zone.

Abstract: An improved sewage treatment system including a horizontally elongated tank divided transversely into a primary, aeration compartment, a secondary, settling compartment and a tertiary, filtering compartment. In a first aspect of the invention, overflow of treated effluent from the tank enters a further treatment section, which may constitute a longitudinal extension of the tank, wherein the effluent is constrained by baffles to flow in an elongated path while having chlorine or ozone mixed therewith to provide further purification. Another aspect of the invention resides in the novel structure of the filtering section wherein filter screens of different guage or opening size are used to achieve a greater degree of purification.

Abstract: A waste water treatment system for the renovation of waste water includes a four stage treatment for removal of gross solids, suspended, colloidal and dissolved organic matter, dissolved nitrogenous material, phosphates odor, color, coliform and residual solids.

Abstract: Liquid treating apparatus wherein the inlet of a settling chamber communicates with the outlet of an aeration chamber. Retaining member(s) in the aeration chamber which divide it into two or more compartments are of sufficient porosity to permit the liquid to flow through at the required rate while retaining materials of a selected configuration or size. A permeable restraining member in the settling chamber separates the inlet from the outlet thereof and is of a mesh to permit liquid flow therethrough in a diffused manner. The restraining member extends above the high liquid level and terminates adjacent to the bottom of the settling chamber. An imperforate partition at the inlet end of the settling chamber carries a porous deflector which extends upwardly and inwardly in the settling chamber to restrain downward movement of liquid passing over the upper end of the partition.

Abstract: An improved, compact biological sewage treatment plant comprised of a series of serially connected treatment tanks of arcuate shape when viewed in top plan view, joined operatively together essentially in an end-to-end circumferential ring-like manner, forming a central space adapted to house additional sludge dehydrating and auxiliary treatment apparatus and equipment for control and maintainance of the plant. A particular advantageous feature includes providing additional concentrically disposed series of said treatment tanks all operatively connected to provide for selectively expandable capacity as needed, with a minimum of adverse environmental impact on the surrounding populace.

Abstract: A method for the anaerobic fermentation of organic waste materials in a digestion zone, which method comprises introducing into the zone algae produced externally of the zone, and/or at least part of the liquid substrate in which such algae have been grown.Apparatus for anaerobic fermentation consisting essentially of a liquid storage tank comprising an inner bag-like container made of flexible material and provided with inlet and outlet means for the introduction of feed materials and the simultaneous removal of liquid and gaseous products, an outer supporting wall or frame, and at least one layer of insulating material arranged between the outer wall of the frame and the container.

Abstract: Apparatus for collection and removal of settled solids from the bottom part of an arcuate sedimentation zone, comprising a scraper blade suspended by cable means from a bridge and drawn reciprocatingly and repetitively in an arcuate path around the sedimentation zone. Means are provided for shortening the suspended lengths of the cable means at the approach of the bridge to a radial end wall of the zone so that the scraper blade is drawn toward the wall for radial alignment therewith, thereby eliminating unscraped `dead space` adjacent the end walls.

Abstract: An integrated system for the separation of liquid and solids entrained in a carrier effluent including a primary gross oil and solids separator, a secondary solids separator and a three stage centrifuge for final separation of fine solids and said entrained liquid from the carrier effluent.

Abstract: Odor suppression in a septic tank sewage system involves reception of sewage in a septic tank wherein solids are allowed to settle; receiving liquids discharging from the septic tank into an enclosed aeration zone outside the septic tank; agitating the liquids in the aeration zone and delivering a stream of air into the liquids being agitated; and draining aerated liquid from that zone, these and other steps are carried out in a particular manner, of unusual advantage.