Abstract: An apparatus provides for treatment of primary effluent from residential and commercial establishments to allow subsurface or surface disposable of wastewater. A single tank includes dosing and recirculation chambers 28, 30 having no direct fluid communication therebetween and divided by a vertical chamber wall 32. A filter layer 26 is positioned atop both chambers such that wastewater that is filtered therein then flows into both the dosing and recirculation chambers. The position of the wall 32 determines the proportion of filtered wastewater that flows into each chamber by gravity.

Abstract: A bioreactor tank is internally partitioned into two chambers within which wastewater is respectively aerated and from which a bacteria purified permeate is withdrawn after filtration, while a high bacteria content remnant is recycled between the chambers to repeatedly undergo biological treatment by aeration within one of the tank chambers.

Abstract: An apparatus for treating organic sludge by aerobic digestion has an aerobic digestion tank 1, a circulation line 6 provided with a pump for pumping circulated sludge, a liquid/gas ejector 7 for aspirating an oxygen-containing gas, which has been humidified, and for mixing it with the circulated sludge, a liquid/liquid ejector 8 for mixing the circulated sludge with sludge in a later step, a downward directing pipe 9 for passing downwards therethrough a gas/liquid mixture and an ozone-treated unit 31.

Abstract: The invention relates to a method and apparatus for recycling a wash solution used in powder coating which uses filters. The invention also relates to methods and apparatuses for recycling wash solutions used in spray washing, steam cleaning or car washes using filters.

Abstract: A filtration apparatus includes a laundry waste sump, a primary 50 micron static screen filter, a 9,000 gallon equalization tank, at least one secondary media/carbon filter, a sludge holding tank with a pump to return excess water to the equalization tank, a backwash pump, an air blower, and a clear well tank water source for backwash. An exemplary embodiment of the invention also includes a surge tank between the primary and secondary filters and a surge tank between the secondary filter and the clear well tank.

Abstract: This metal containing waste water treatment method introduces a metal containing waste water from above into a submerged membrane separation tank 1 in which a reaction section 2, a submerged membrane section 3 having a submerged membrane 5 and a precipitation section 4 are arranged in order from top to bottom, causes a reaction by adding a pH adjuster to the reaction section 2, subsequently separates water from metal by the submerged membrane 5 of the submerged membrane section 3 and subsequently precipitates and concentrates the metal in the precipitation section 4. As described above, according to this treatment method, the pH adjuster is added to the reaction section 2, and therefore, solid-liquid separation can be effected by the submerged membrane 5 with a hydroxide formed. Moreover, the metal can be precipitated and concentrated by the action of gravity without using energy in the precipitation section 4.

Abstract: An apparatus and method are provided for removing accumulated underwater debris from a reservoir for a recirculating water system, such as used for a golf course sprinkler system. An eductor is provided which is driven by a high pressure water pump. The high pressure creates a vacuum which is utilized to actuate a vacuum line. The vacuum line is moved to and fro in the reservoir to entrain the debris from the reservoir in water and to carry the entrained debris to the eductor. The entrained debris is discharged from the eductor into a separator having a permeable membrane which traps the debris and allows the water to return to the reservoir. Various separators are provided. The eductor includes an adjustably mounted nozzle to adapt to different sized debris being removed from the reservoir.

Abstract: A self contained filter for a recirculating tank is used in a septic system. The self contained filter is a mattress-like filter made of woven material encapsulating aggregate material therein. The weave of the mattress-like woven material is smaller than the aggregate material. In another aspect, at least one mattress-like filter is placed within a tank.

Abstract: The invention is a water purification system through denitrifying reduction with faculative anaerobes in which a nitrate harmful in the breeding of creatures such as tropical fishes and coral for appreciation and fishes and shellfishes for food and the like is decomposed and denitrifying-reduced in a short time. In this case, an aerobic circulating pathway of water reduced through a filter using aerobes is separately arranged from an anaerobic circulating pathway of water reduced through a closed type anaerobic filter device (10) using anaerobes. A nitrate produced in the aerobic circulating pathway is exuded into the anaerobic circulating pathway through powdery sand (5). This nitrate is decomposed in the anaerobic circulating pathway. A nitrogen gas inside the anaerobic circulating pathway produced in the decomposition of the nitrate is discharged at an isolated state so as not to contact with water in the aerobic circulating pathway.

Abstract: There is a process for removing by-product tar during the manufacture of isopropyl alcohol. The process comprises the following: a) reacting propylene with concentrated sulfuric acid and water to form isopropyl alcohol and a spent acid having a by-product tar; b) capturing at least a portion of the isopropyl alcohol; c) contacting the spent acid with a gas in bubble form; d) allowing a least a portion of the tar to separate from the remainder of the spent acid to form a layer of tar and a layer of cleaned acid solution; e) capturing the tar; and h) recycling the cleaned acid solution to step a) as a source of sulfuric acid. There is also a process for removing by-product tar during the manufacture of methyl ethyl ketone. The process is substantially the same except that 1-butene is substituted for propylene. There is also a process for removing tar from a spent acid.

Abstract: An apparatus for the fixed-film anaerobic digestion of flushed livestock manure includes an enclosed digester tank (fixed or flexible roof), internal media for biofilm development, a biogas collection and flare system, various pumps, and hydraulic control systems. The preferred media has substantially vertically-oriented, uninterrupted channels to promote enhanced bacterial attachment and biofilm development. The immobilization of microbial biomass within the reactor as a biofilm allows effective treatment of the wastewater at ambient and higher temperatures, as well as reasonable hydraulic retention times. The composition and concentration of bacterial groups in the biofilm developed on the media in the fixed-film digester result in a significantly enhanced anaerobic degradation process. This novel fixed-film digester design expands the potential application of anaerobic digestion to dilute livestock waste with significant levels of suspended solids.

Abstract: A fluid filtration assembly (10) operable to provide both return-side and supply-side filtration, as, for example, of a fluid entering and leaving a sump (14) as it circulates in a vehicle transmission (12). The fluid filtration assembly (10) broadly comprises a return-side filter (18) and a supply-side filter (20). The return-side filter (18) includes a filter media (33) operable to filter relatively small particles. Fluid flow through the return-side filter (18) may be accomplished using any of three described alternative embodiments, including upflow, downflow, and direct feed. The supply-side filter (20) includes a filter media (42) for filtering needed fluid as it is drawn back into circulation. The supply-side filter media (42) is a low restriction filter media operable to filter only relatively large particles, thereby decreasing bottle-neck effects and minimizing pressure drops.

Abstract: An apparatus for treating water contaminated with metal sulfates and sulfuric acid such as acid mine drainage (AMD) which in part recycles high pH effluent from later steps in the process back to the earlier steps of the process. The recycled high pH effluent added with magnesium hydroxide to the entering AMD generates precipitates separable from the stream to leave sulfate ladened water. A tangential filtering process is used to separate the sulfate ladened water into one stream of pure water and a second stream containing sulfate. One portion of the second stream is treated with ammonia to yield a cake of ammonia sulfate and aqueous ammonia. Ca(OH)2 is added to another portion of the second stream to produce calcium sulfate cake and the high pH effluent that is recycled back to the first step in the cycle.

Abstract: An enhanced activated sludge wastewater treatment method increases volumetric pollutant loading, hydraulic loading capacity and nutrient removal efficiency at a conventional activated sludge wastewater treatment plant. The method describes the control of return activated sludge rates, and the operation of partitioned aeration and reaeration zones according to measured properties of the mixed liquor to achieve the claimed benefits. Operating an existing treatment plant according to the enhanced treatment method provides a more consistent treatment process that is resistant to shock loading and increases plant capacity without the need for costly construction and operation of additional reactors and clarifiers.

Abstract: A self contained filter for a recirculating tank is used in a septic system. The self contained filter is a mattress-like filter made of woven material encapsulating aggregate material therein. The weave of the mattress-like woven material is smaller than the aggregate material. In another aspect, at least one mattress-like filter is placed within a tank.

Abstract: A paint overspray particulate filtration system includes a collection tank, a floatation consolidation tank, and a vacuum filter assembly having a filter medium that traverses a pair of vacuum chambers. A positive displacement vacuum producer for the first vacuum chamber discharges a first supply of pressurized air at a temperature preferably greater than about 170° F. and a pressure preferably greater than about 6 psig, while a centrifugal compressor discharges a second supply of pressurized air at a temperature of perhaps up to 110° F. and at a pressure of perhaps 4 psig. The first pressurized air supply is heat exchanged with the second pressurized air supply, whereupon the cooled first pressurized air supply is directed through a submerged diffuser nozzle to aerate the collection tank and/or the consolidation tank. The warmed second pressurized air supply is directed onto the paint sludge carried atop the filter medium to enhance sludge dewatering.

Abstract: A fluid filtration system of well workover fluids, the system comprising: a first settling tank which stores fluid; a second settling tank which stores fluid; a low pressure pump in fluid communication with the first and second settling tanks; a low pressure filter in fluid communication with the first and second settling tanks; a high pressure pump in fluid communication with the second settling tank; and a high pressure filter in fluid communication with the second settling tank, wherein the high pressure filter comprises: an inlet; an outlet; a plurality of input feed lines in fluid communication with the inlet; a plurality of output feed lines in fluid communication with the outlet; a plurality of filter canisters, wherein at least one filter canister is in fluid communication with each input feed line and each output feed line.

Abstract: A system for filtering well water residing in a water storage tank or reservoir in which water laden with sediment and debris is removed by a pump from the center of the bottom of the tank, passed through one or more sand filters, and returned to the tank. The suction caused by the pumping action creates a vortex in the water in the storage tank which promotes the collection and accumulation of sediment and debris in the center of the bottom of the tank. The tangential injection of the return water aids in the creation of the vortex or swirling motion around central axis of rotation which in turn causes particulate matter, dirt, and debris to gravitate to the bottom of the tank and collect in the center of the tank's floor, which is skimmed by either the same or a separate stand-alone pumping action. The degree of separation of the particulate matter from the well water is substantial with a large majority of the particulate matter accumulating near the center of the bottom of the tank.

Abstract: In a vertical shaft bioreactor, improved devices and methods are provided for enhanced secondary and/or tertiary treatment of wastewater, including residential, municipal and industrial wastewater. The devices and methods of the invention are useful for enhanced secondary wastewater treatment, including BOD and TSS removal. Tertiary treatment can alternately or additionally be achieved in the bioreactor with nitrification of ammonia, with nitrification and denitrification, and with nitrification, denitrification, and chemical phosphorus removal. A vertical shaft bioreactor is also provided which achieves thermophilic aerobic digestion and pasteurization of sewage sludges, optionally to produce class A biosolids.

Abstract: A method and apparatus for processing waste streams wherein a slipstream is formed on the upstream side of an ultrafiltration membrane (120) to carry collected and concentrated filter reject to a microfilter (170) via a slipstream through a conduit (155) at a very low flux through the microfilter. The low flux gives the particles in this stream a chance to interact and thus form an irregular matrix that itself helps to trap particles. The effluent from this matrix and microfilter is returned upstream of the ultrafiltration membrane via a conduit (165) to be repeatedly collected and concentrated. The suspended solids removed from the reject stream and microfilter may then be disposed of directly without further processing. For metal ions, the removal efficiency of ultrafiltration membrane can be improved by injecting sulfide compounds or other compounds upstream of ultrafiltration membrane.

Abstract: Said equipment include a tank-filter (1, 15) in which a pretreatment stage is carried out. The tank (1) is a decanter to which a flocculant that is uniformly mixed with an agitator (3) can be added. The sludge is removed by delivering it to a filter bag (5). The permeates are then fed to a collecting tank (6) and pumped to the same tank (7) receiving the clarified waters. The permeates are then decanted from said tank (7) through a safety filter (8) to a battery of activated carbon columns (9) where they arm purified by adsorption until the established threshold values have been reached. In another embodiment, the reservoir-filter (15) is a polypropylene bag filter with diatomaceous earth, wherein the liquid passes directly to the decanting tank and is then pumped to the battery of activated carbon columns (9).

Abstract: A filtration system for cleaning the fluid in a wash tank. The filtration system includes a process tank from which fluid is pumped to a filter element located in the wash tank. The filter element is formed of hollow porous tubes. The fluid is pumped from the process tank through the hollow porous tubes and back to the process tank. The fluid in the hollow porous tubes is at a greater pressure than that of the fluid in the wash tank in which it is submerged, such that fluid, but not particulate matter, with flow through the pores in the tubes to the wash tank. Cleaned fluid is thereby provided to the wash tank and fluid with a higher concentration of contaminants is returned to the process tank.

Abstract: A filtration apparatus includes a laundry waste sump, a primary 50 micron static screen filter, a 9,000 gallon equalization tank, at least one secondary media/carbon filter, a sludge holding tank with a pump to return excess water to the equalization tank, a backwash pump, an air blower, and a clear well tank water source for backwash. An exemplary embodiment of the invention also includes a surge tank between the primary and secondary filters and a surge tank between the secondary filter and the clear well tank.

Abstract: A filtration system for processing effluent from septic-based sanitation systems includes at least one treatment tank for receiving effluent from a septic tank. The tank includes filtering media therein, the filtering media adapted for filtering the effluent to produce filtered effluent. The system includes structure for recirculating the filtered effluent, wherein a first portion of the filtered effluent is directed back onto the filtering media and a second portion of the filtered effluent is directed out of said tank. The system can obviate the need for a drain field in septic-based sanitation systems.

Abstract: A system and method for removing pollutants from wastewater. The system includes a constructed wetland cell in which the filtered wastewater is flowed generally vertically. The flow of wastewater is unsaturated through the wetland cell to aerate the wastewater. The wastewater may be further aerated by a blower or injector. The treated wastewater from the wetland cell is blended with untreated wastewater, then either recirculated through the wetland cell or conveyed to a disposal system.

Abstract: The invention relates to a method of recycling wash-water resulting from the treatment of a film provided with a carbon particles based backing layer, and especially from a washing treatment to remove the said carbon particles based backing layer. The method comprises the step of passing the wash-water through an microfiltration unit equipped with a microfiltration membrane made from a polytetrafluorethylene-based membrane. The method enables the regeneration of the wash-water and its recycling with a high efficiency and considerable lowering of the water consumption used in this step of the processing.

Abstract: A process for the removal of oil from oil-contaminated water is efficient, inexpensive, and capable of oil removal to a level where the water may be disposed of by conventional sewage treatment or reused. The apparatus which performs the process consists of an elongate housing having at least one upwardly extending oil collection tower and an oily water inlet mediate the oil or oil-enriched water outlet and the “clean” water outlet. The elongate housing and preferably also the oil collection tube are filled with beads of hydrophobic polymer.

Abstract: A fluid filtration system of well workover fluids, the system comprising: a first settling tank which stores fluid; a second settling tank which stores fluid; a low pressure pump in fluid communication with the first and second settling tanks; a low pressure filter in fluid communication with the first and second settling tanks; a high pressure pump in fluid communication with the second settling tank; and a high pressure filter in fluid communication with the second settling tank, wherein the high pressure filter comprises: an inlet; an outlet; a plurality of input feed lines in fluid communication with the inlet; a plurality of output feed lines in fluid communication with the outlet; a plurality of filter canisters, wherein at least one filter canister is in fluid communication with each input feed line and each output feed line.

Abstract: An installation for recovering debris stopped by a filter at the inlet of a heat exchanger: a washing water manifold (36) at the outlet of the filter (11) feeds a separator (37) provided with an outlet pipe (39) for water free of debris to which is connected a hydro-ejector (50) which is connected to the outlet pipe (16) of the exchanger (19).

Abstract: A truck houses a closed recirculation system having a series of hoses, filters and pumps interconnecting a first point and second point, preferably hydrants, of a water supply system. A flow of water pumped outside of the water supply system through the filters causes an increased water flow within the section of the water supply system between the second and the first point to clean the section of deposits, sediment, particulates and other undesirable matter. All of the filtered water is returned to the water supply system. The water may be inspected and chlorinated.

Abstract: A wastewater treatment unit (10) including a recirculation chamber (32), a dosing chamber (34) having no direct fluid connection to the recirculation chamber (32), and at least two filter layers (28, 30) in a single tank (12). Each filter layer (28, 30) containing filter media (56) and being located above the recirculation (32) and dosing chambers (34). The wastewater treatment unit (10) also including an influent pipe (50), a recirculation pump (72) located in the recirculation chamber (32), and an effluent discharge pipe (88) connected to the dosing chamber (34).

Abstract: Disclosed is a bioreactor apparatus having a bed of buoyant media pellets floating within a filtrate to be processed. The apparatus includes a tank (22) having a peripheral wall for containing filtrate (34) and a bed (36) of media pellets (38). A central manifold (100) is rotatably supported within the tank, the central manifold being mounted for rotation about a vertical axis (22) and having a plurality of longitudinally spaced openings (140) intermediate its ends, the openings adapted to eject filtrate in a generally horizontal direction and along a substantially vertical plane toward the wall of the tank, cyclically fluidize pellets in a directly narrow zone. In a preferred aspect, there is also a thrust manifold (140), generally parallel to the axis of the central manifold and having a plurality of longitudinally spaced openings intermediate its ends directed horizontally and generally perpendicularly to the plane.

Abstract: A treatment and filtration device for use with a wastewater output contaminated with a chemical associated with a dry cleaning operation. An enclosed basin is capable of being filled with a volume of the wastewater for timed treatment. A first elongated module is arranged within the basin at a first location, the first module accomplishing initial filtration of the wastewater and substantial recovery of the chemical contaminant. A second elongated module is arranged within the basin at a second spaced apart location relative to the first module, a series of exterior and porous membranes interconnect the first and second modules as well as inwardly opposing wall edges of the basin proximate the modules and in order to divide the basin into first and second zones. The second module vaporizes a substantial remaining component of the chemical contaminant concurrent with discharging, from the first zone into the second zone, a further filtrated water output.

Abstract: The process is composed of the following steps: (a) production of the fresh wiping solution, (b) introduction of the fresh wiping solution into one or more wiping tanks, where it is contaminated by the inks. In addition, it comprises the following steps: (c) treatment of the used solution exiting from the wiping tank or tanks with a chemical agent, producing a solution and sedimented ink, (d) separation by settling of the solution obtained in step (c), producing a clean solution and a concentrated solution with sedimented ink, (e) filtration of the concentrated solution, producing a clean solution and solid waste, and (f) use of the clean solution obtained in steps (d) and (e) as fresh wiping solution.

Abstract: A wastewater treatment system for use with a conventional septic tank, or other small-scale wastewater treatment facility, for enhancing wastewater treatment without requiring complex control or maintenance limitations. The system incorporates a plurality of primary functions that combine to oxidize, nitrify, denitrify and remove water borne total dissolved solids prior to effluent discharge. Included is a fluidized-bed reactor containing biofilm attached to carrier particulates for use in the purification of wastewater. The fluidized-bed reactor is configured to include two distinct regions, namely a “lower” aerobic region and an “upper” anoxic region, during normal operating conditions. The lower aerobic region uses aerobic facultative bacteria to oxidize Carbonaceous Biochemical Oxygen Demand (CBOD), organic (Kjeldahl) nitrogen, and ammonia while consuming the dissolved oxygen in the water.

Abstract: Method and multipurpose apparatus for internally cleaning a hydraulic control system are disclosed. The method is carried out by establishing a turbulent flow of cleaning fluid through the hydraulic control system and maintaining the turbulent flow until the hydraulic control system has been cleaned without diverting a portion of cleaning fluid through a bypass valve, by use of a variable speed pump coupled to a fluid accumulator. The apparatus comprises a filtration system for cleaning up recovered fluid, a primary pump, an accumulator, a first manifold for fluid injection, a second manifold for fluid recovery, and a return conduit from the second manifold to the filter.

Abstract: The present invention provides a system and method for selectively removing one or more organic and also preferably one or more inorganic contaminants from plating baths. More particularly, the invented method relates to the use of a source of energy in combination with chemical oxidants, alone or in conjunction with a catalyst to oxidize organic contaminants in the plating bath to a level such that the electroplating bath can be recovered and reused after appropriate chemical adjustment. The oxidative treatment method may be a continuous process or a batch process that is performed in a single pass and the endpoint of the oxidative process detected by a sensor. Residual organics, if desired, and chloride ions in the bath are removed from the solution by a chemisorption or physisorption treatment.

Abstract: A wastewater treatment system includes a septic tank having a discharge in flow communication with a plurality of biofilter containers having filter media therein. Wastewater or effluent from the septic tank is allowed to trickle downwardly through the filter media and each container includes an outlet for discharging the wastewater to the environment or transferred to other treatment facilities.

Abstract: An integrated biological treatment process and bioreactor system provides means for simultaneous removal of biodegradable solids (TSS), nitrogen (N) and phosphate (P) from water and wastewater. The system comprises microbial consortia immobilized in separate bioreactors for anaerobic processes, P removal, denitrification and, optionally, BOD removal and polishing.

Abstract: An apparatus for converting a typical anaerobic septic tank system into an efficient aerobic treatment system for treatment of liquor containing biodegradable wastes. The apparatus includes a collapsible reactor module that can pass through a relatively small opening in a septic tank cover. The reactor module contains media through which liquor to be treated is recirculated and aerated.

Abstract: In a filtration system wherein wastewater is recirculated back through a filtration bed for a second pass therethrough, the recirculated wastewater being directed through a set of secondary distribution pipes located in the filtration bed below those distribution pipes through which the wastewater is first carried through the bed, with hood elements arched over the respective secondary pipes.

Abstract: A method and apparatus for flushing flush lanes comprising providing a process pit to recycle flushed water; providing a solid waste separator; providing a storage lagoon; pumping a first selected volume of water from the storage lagoon and a second volume of water from the process pit through the flush lanes; collecting water flushed through the flush lanes and solid waste carried therewith in the process pit; separating solid waste from a third volume water from the process pit in said solid waste separator and returning the third volume of water less the solid waste to the storage lagoon.

Abstract: The apparatus is a small flow wastewater treatment system. The system uses a recirculating packed media filter for the initial treatment of effluent from a device such as a septic tank. The incoming wastewater is furnished to the recirculating packed media filter intermittently to permit air into the filter for maintaining high levels of oxygen for bacteria action. The recirculating packed media filter is followed by a subsurface flow constructed wetland. The wastewater entering the apparatus of the invention is divided into two parts so that 5 to 25 percent of the incoming flow bypasses the recirculating packed media filter and goes directly into the subsurface flow constructed wetland to encourage bacteria action that converts nitrates into gaseous nitrogen.

Abstract: In a filtration system wherein wastewater is recirculated back through a filtration bed for a second pass therethrough, the recirculated wastewater being directed through a set of secondary distribution pipes located in the filtration bed below those distribution pipes through which the wastewater is first carried through the bed, with hood elements arched over the respective secondary pipes.

Abstract: A continuous flow slurry cleaning method, apparatus and system including a filter portion and a mud re-circulation manifold for receiving partially filtered slurry, containing the slurry and mixing the slurry with liquid ready for use and thereby enabling a continuous, re-circulating flow through the filter portion. The continuous flow slurry cleaning apparatus and system further include a tank for storing and delivering liquid ready to be used by a drilling machine. The continuous flow slurry cleaning method, apparatus and system further includes a mud circulation/agitation system for keeping solids in suspension and for mixing additives along with the liquid ready for use and thereby modifying the makeup of the liquid ready for use.

Abstract: An apparatus using activated sludge for the removal of biological nutrients from a wastewater includes a bioreactor for containing a mixture of wastewater under treatment and activated sludge. The bioreactor is divided into a plurality of serially connected treatment zones and includes a wastewater inlet, a downstream aerobic zone and an upstream aerobic zone between the wastewater inlet and the downstream aerobic zone. A membrane filter is provided in the downstream aerobic zone so that it functions as an immersed membrane filter with a bioreactor containing an operative volume of wastewater and activated sludge. The immersed membrane filter filters treated water flowing from the bioreactor through a first outlet. An aerator is operative associated with the membrane filter for purging solids from the membrane filter.

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, BOD OR 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 device of three-chamber type for purifying liquid in a cup-shaped vessel (17, 18) has an inlet tube (20) for the liquid at a certain level and an outlet tube (21) at a lower level than the inlet tube. The vessel is vertically divided by a substantially horizontal distribution disc (14) below the inlet and outlet tubes. The disc has at least one opening (19) and is provided with a substantially vertical distribution pipe (15) for receiving the liquid from the inlet tube (20). A first sedimentation chamber (A) is formed below the lower end of the distribution pipe (15), a second chamber (B) is formed over the lower end of the distribution pipe (15) and below the distribution disc (14) and a third chamber (C) is formed over the distribution disc (14).

Abstract: The invention relates to a method for separating solid particles from a liquid in a dish-washer. For the separation a filter (19) of expanded metal is provided, which forts openings (21) the bounding surfaces (22) of which are inclined in relation to the plane of the filter. The liquid with particles entrained therein is directed towards descending bounding surfaces in the filter for guiding the liquid flow through the filter under separation of the particles from the liquid.

Abstract: The present invention relates to a sludge treatment plant in which sludge is flocculated and then dewatered to form a cake and a reject liquor is modified by recycling 3 to 40% of the reject liquor into the sludge immediately before the dewatering process.