Abstract: Displacement washing of slurry body is provided in a centrifuge filter (peeler centrifuge) by introducing wash liquid along the inner surface of the drum while the drum is rotating. The wash liquid moves through the filter into the slurry body in a broad front to displace the mother liquor of the slurry body toward the axis of rotation of the drum. The mother liquor is removed by an overflow pipe or dip tube to a point outside the centrifuge filter for disposal.

Abstract: A process for the removal of cyanides from contaminated oily solid waste performed by utilizing a single processing zone wherein multiple processing steps are carried out to remove contaminants. The steps include loading a contaminated oily solid waste into a zone where the solid is reduced in size, adjusting the pH of the oily solid waste, dewatering or deoiling the oily solid waste and drying the resulting solid, extracting the resulting dried solid with organic solvent, and further drying the extracted solid to remove residual moisture, cyanide, solvent, and volatile organics.

Abstract: A wire-type pulp washing machine includes an endless moving foraminous wire which extends about a breast roll defining an on-running end and a couch roll defining an off-running end with a generally horizontal upper run of the wire extending between the rolls with showers providing a counter-current washer. The endless wire forms a wire return run having a horizontal wire section beneath the upper run. Pulp which has been washed on the upper counter-current washer may be removed and subjected to a chemical action, such as a bleaching action, and then reapplied to a horizontal return run section of the wire by a headbox to form a pulp mat on the inside surface of the wire. This pulp mat is subject to further countercurrent washing by the application of wash water to an upper surface of the mat and by draining of the wash water through the wire by suction boxes. This wash water may advantageously be applied as the wash water to the last stage of the counter-current washer along the upper run.

Abstract: A method for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream.

Abstract: Method and apparatus for treating a gas containing aqueous fiber suspension in a fiber line process of a pulp mill including at least one of pulp screening, washing and bleaching includes (a) transferring the gas containing fiber suspension at a consistency to a treatment station; (b) treating said fiber suspension at the same level by removing a portion of the water from the fiber suspension so as to generate aqueous filtrate and treated fiber suspension having a relatively higher consistency; (c) simultaneously pumping and degassing the filtrate at the same level; and (d) pumping the treated fiber suspension having the relatively higher consistency away from the treatment station at the same level by imparting to the treated fiber suspension sufficient shear force so as to render the fiber suspension pumpable.

Abstract: A batch type process for purification of a polymer resin, in which a predetermined volume of acid is rapidly emptied and stirred into a fixed volume of polymer slurry for chemically treating impurities in the slurry, is converted to a continuous operation by supplying a substantially constant stream of polymer slurry and a controlled stream of acid to a mixing vessel. pH control of the polymer slurry required for effective purification of the polymer resin is achieved by manipulating the flow rate of the acid stream responsive to a feedforward control signal which operates in conjunction with a feedback signal. The feedforward signal is based on an upstream measurement of slurry flow rate to the mixing vessel and the feedback signal is based on a downstream pH measurement of slurry flowing from the mixing vessel.

Abstract: A method of rinsing a slurry contained between a pair of converging mesh belts comprising the steps of splitting the slurry into two streams, each stream adjacent one of the converging mesh belts, introducing a stream of rinsing fluid between the two slurry streams, the point of introduction of the rinsing fluid between the two slurry streams is not more than 12 inches before and not more than 72 inches after the slurry streams contact the converging mesh, and creating compressive forces within the pair of mesh belts, which compressive forces continue for a distance of at least 24 inches after introduction of the stream of rinsing fluid.

Abstract: An improved solvent dewaxing process in which a method and apparatus for continuous hot wash of a dewaxing filter is disclosed. A hot wash solvent is continuously sprayed below the doctor blade followed by a cold solvent spray below the hot solvent spray. Additionally, a solvent management process for changing the proportions of the solvent in response to different viscosity feedstocks thereby increasing filtration efficiency is also disclosed.

Abstract: Phosphoric acid wastewater treatment to substantially eliminate discharge of contaminants to the environment. Acid pond water from conventional wet-phosphoric acid manufacturing is replaced by gypsum pond water having a pH closely matching that of the surroundings. Essentially all fluorides are insolubilized and substantially all phosphoric acid is recovered, minimizing loss to the environment.

Abstract: Tall oily fatty acids when combined with certain non-ionic surfactants having an HLB number from 10-14 are superior dewatering agents for Bayer Process alumina trihydrate filter cakes.

Abstract: In a method for filtering a suspension through a stationary filter having a vertical filter element arranged in a pressure vessel and for re-conditioning the filter after filtering, the filtrate is discharged from the bottom of the filter element during the main part of the filtering. After filtering, unfiltered suspension is discharged in a known manner from the pressure vessel later to be returned to the suspension inlet. Thereafter, back-wash is performed with another medium other than filtrate, an outlet for material deposited on the filter element being opened for removal of said material together with the back-washing medium. Preferably, before back-wash, drying of the material deposited on the filter element takes place by means of a gas medium circulating within the filtering plant.

Abstract: A process and apparatus for treating waste which contains ferromagnetic components, such as the grinding sludge from grinding ferromagnetic materials which contains ferromagnetic particles contaminated with water and oil, in which the waste is introduced into a separating tank containing a washing solution and mixed with the solution by stirring until the oil dissolves. Subsequently, a magnetic field is produced at the separating tank wall which causes magnetic components to accumulate on the wall. The wash solution is then filtered to remove non-ferromagnetic solids. The magnetic field is subsequently removed, and accumulated ferromagnetic components are released into the wash solution. The ferromagnetic components are then filtered out from the wash solution and dried, and the filtered wash solution is conveyed to an oil separation tank where oil separated from the waste is recovered.

Abstract: In the process for the purification of diemthyl terephthalate (DMT) by recrystallization from methanolic solution, the mother liquor containing the impurities, substantially the isomers DMI, DMO and aldehydes, is separated off and passed to a workup tank. The moist crystals are dried by melting with the evaporation of methanol. The mother liquor is then separated off by filtration, and the moist crystals obtained from the separation are washed before melting. The washing liquid is recycled together with a portion of the separated mother liquor into the recrystallization tank.

Abstract: A method is described for safely and effectively washing solid gels or films containing biological macromolecules such as proteins or nucleic acids. The method involves placing the gels in an open plastic container and decanting a wash solution horizontally so as to leave the gel at the bottom of the container without using external means to hold the gel down. The undamaged gel can then be safely removed and detection experiments can thus be carried out. A preferred apparatus for carrying out this method is also described and consists of an elongated open-topped side spouted tray.

Abstract: Improved filtration rates and decreased sodium chloride and moisture content in sodium bicarbonate filter cakes are obtained by including a filter aid containing a mono and/or dialkylester of sodium sulfosuccinate in the filter feed suspension.

Abstract: A continuous process for the separation of small particles from larger particles in a biological preparation passes a liquid stream of the preparation through a first filter or screen, which retains larger particles, passing smaller particles in the liquid. The large particles have retained on their surfaces wetting water, in which are entrained some of the small particles. The large particles are directed to a liquid having a concentration of smaller particles lower than the concentration of smaller particles in the wetting water, and mixed therein. The smaller particles separate from the larger particles in the mixed suspension, which is then directed to a second filter or screen, for further separation. The smaller particle/liquid stream may be recycled to the biological preparation stage, the liquid suspension for the large particles, or to a separator means where the smaller particles are separated off from the liquid stream.

Abstract: A method and apparatus for removing pollutants from contaminated soil in which the soil is first purified from coarse constituents by screening or crushing and then subjected to extraction with washing water mixed with additives, after which the soil is separated from the washing water and additionally rinsed with rinsing water whereupon the rinsing water is freed in a purification process from the pollutants extracted from the soil. The extraction with washing water, which may contain additives if required, is substantially separate from the single or mulit-stage rinsing and sorting process; a very fine fraction having a particle size up to 150 .mu.m, and preferably up to 10 .mu.m, is separated by dry or wet sorting before extraction; and the dried very fine fraction is distilled at a temperature of 300.degree. C. to a maximum of 600.degree. C., preferably distilled in vacuo at a temperature of 380.degree. C., for purification from organic pollutants and from cyanide and mercury compounds.

Abstract: After quenching, the slag that is generated in garbage and waste incinerators is subjected to an additional washing process in a washer unit (2). During the wash process, harmful substances such as chlorides and heavy metals, for example, are washed out of the slag. The subsequent separation of the water from the slag is effected in a separator system (4) and in a drying system (7). The slag is dried to a maximum water content of 20% and the fine components with a grain size of less than 2 mm are removed from the slag either during or after the drying process. These fine components and the wash water sludge contain practically all the soluble harmful substances, and must be processed or dumped while observing special precautions. The remaining clean slag is practically free of soluble harmful substances and can be used as construction material.

Abstract: Hydrocarbons are recovered from acid sludge by mixing the sludge with methyl ethyl ketone and base. A hydrocarbon-rich methyl ethyl ketone stream and a solids-containing stream are separated from the mixture, and a hydrocarbon stream is separated from the hydrocarbon-rich methyl ethyl ketone stream.

Abstract: A container having a longitudinal passage is provided with a filter for collecting thereon cellular components having a particle size range of 5 microns or greater. Where the cellular components are to be harvested from a hostile environment such as voided urine specimen, the hostile environment is discharged, after passing through the filter, from the container through one end thereof to separate the cells from the hostile environment as soon as possible. The cellular components harvested on the filter are washed with a suitable media such as a saline solution and a nutrient preservative media, or fixative, such as by way of example formaldehyde is added to the container to assist in stabilizing the harvested cellular components on the filter. Where the cellular components are harvested from a hostile environment, a suitable closure may be added to one end of the container to close off the longitudinal passage before the preserving media is added.

Abstract: A centrifugal separation method for living cells is disclosed in which a cell containing solution is charged in a rotor chamber confined by a steam pressure-resistant wall. A rotor having septa is disposed in the rotor chamber. The septa are rotatable in the same direction at the same angular velocity as the rotor while at least part thereof is immersed in a solution in the rotor when cells are to be centrifuged from the cell-containing solution. After the cells are separated and adhered to the inner surface of the rotor, a supernatant in the rotor is discharged from the rotor. Then a fresh cultivating medium is introduced into the rotor, and the septa and the rotor are rotated at mutually different angular velocities while at least part of the septa is immersed in the fresh medium in the rotor. As a result, the cells are again suspended in the fresh medium.

Abstract: In a vacuum belt filter, in order to allow for additional washing of filter cake, a plate is mounted in an inclined disposition above the upper run of the belt with its lower end directed upstream so that as the belt is progressed filter cake moves up over said plate. At the top of the plate, the cake drops into a receptacle and is washed and reslurried by liquid from jets before being returned to the belt downstream, preferably immediately below, the inclined plate. As an alternative to immediate return to the belt, reslurried cake may be transported from the receptacle to a reservoir for further washing or prolonged leaching before it is returned.

Abstract: Heavy metals are reclaimed from a concentrated wastewater solution containing heavy metal cations and an acid by adding to the wastewater a bed of scrap aluminum in a total amount between about 160% and about 180% of the stoichiometric requirement for complete reduction of the dissolved heavy metal cations to their elemental states and adjusting the acid content of the wastewater to 5% to 20% by volume and allowing the heavy metal cations to react with the scrap aluminum to oxidize the aluminum and to reduce the heavy metal cations to their elemental states thereby producing demetallized wastewater which is neutralized with caustic to produce a treated effluent.

Abstract: This invention relates to a method of improving the dewatering of alumina trihydrate obtained by the Bayer process. The method comprises treating the alumina trihydrate with the product of mixing an alkaline liquor and a C.sub.8 to C.sub.20 fatty acid, fatty acid precursor such as an ester or amide, or a fatty acid blend. The product, a fatty acid salt, is an effective dewatering aid.The alumina trihydrate may be washed with a liquor including said product, or the product may be added to a Bayer liquor slurry prior to filtration of the alumina trihydrate.The invention also contemplates a watering aid consisting of the product of mixing an alkaline liquor with a C.sub.8 to C.sub.20 fatty acid or fatty acid precursor.

Abstract: It is desirable to be able to treat medium consistency (e.g. about 8-12% by weight) paper pulp suspensions with treatment liquid (e.g. a wash liquid), and to thicken the pulp to about 30-50% consistency at the same time. A moving (e.g. rotating) channel is defined by a root wall and upstanding side walls--some or all of which are perforated--and treatment liquid is introduced by an arcuately elongated distributor with perforated side walls into the center of the pulp within the channel, filtrate flowing out through the perforated walls. A pivoted wall portion of the stationary housing of the treatment device restricts outflow of the thickened pulp cake from the device, the cake flowing between a doctor blade and the pivoted wall portion.

Abstract: The present invention relates to a process and a device for selectively separating the solvents employed in the preparation and purification of products. In this connection the different solvents are removed from the product to be treated by means of mechanical separation and subsequent admission of steam, and are collected separately. As a result of this, mixing of solvents from the preparation and from the purification is avoided, so that the working up of a solvent mixture is superfluous. The proces and the device are preferably used in the process for producing starch ethers and cellulose ethers.

Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material, adsorbing residual contaminants from the liquid fraction are adsorbed onto decomtaminated solids to produce decontaminated liquids and contaminated solids.

Abstract: A process and apparatus for the separation and purification of cellulose ethers and other cellulose derivatives in a filter unit at relatively high temperatures and with narrow-mesh filters, employing a pressure vessel having candle filters to which pressure is introduced for separation of the suspension liquid, for the removal of residual liquid from the filter cake formed, and also for washing the filter cake.

Abstract: A column unit is provided consisting of a centrifuging vessel and a receiving body with feed and discharge openings located at opposite ends. Desired column material is located within a middle portion of a hollow cylinder of the receiving body. A portion of the receiving body containing the discharge opening and the column material is received by the centrifuging vessel. The entire column unit is inserted into a conventional stand in a centrifuge. Accordingly, when sample material is introduced into the receiving body through the feed opening, it may flow without misdirection through the column material and discharge opening and into the centrifuge vessel.

Abstract: A process is disclosed for recovering a cellulose ether from a cellulose ether suspension in which the cellulose ether is recovered as a filter cake from a pressure filtration, particularly using a rotary pressure filter. Clogging of the separation or filtration device is avoided, providing for a long useful life. A multi-layer wire mesh filter medium is employed, formed of mesh layers of different wire thicknesses and/or mesh size. After removal of the filter cake, the filter medium is cleaned with steam, compressed air or pressurized water.

Abstract: The invention concerns a method for treatment of solid and fluid materials contaminated by at least predominantly lipophilic harmful substances, in particular hydrocarbons and the like, especially for oil-infested grounds and waters, as well as suitable systems and emulsifier substances for carrying out the method. The contaminated materials, for microdispersed emulsifying of the harmful substances, is intimately mixed with at least one emulsifying substance as well as possibly with water. Subsequently, the emulsion is separated from the material while adding water, and preferentially biologically decomposed.

Abstract: The invention relates to processes and apparatus for the elutriation of particles of a Ziegler-Natta type alpha-olefin polymerization catalyst, based on transition metal compound(s) and preferably also comprising magnesium compounds, by means of an elutriation liquid which is a non-polar liquid, for example a hydrocarbon chemically inert in relation to the catalyst. A preferred process comprises the following stages:preparation of a homogeneous suspension of the catalyst in the elutriation liquid, andelutriation of the catalyst by means of the suspension and the elutriation liquid in one or two elutriation columns (F1),(F2), separating the large and fine catalyst particles respectively.The apparatus comprises a tank (M2) for the preparation of the catalyst suspension and the elutriation column or columns (F1),(F2).

Abstract: The present invention relates to a method and an apparatus for washing pulp according to which method the pulp is supplied onto a movable liquid-pervious support surface (2) to form a substantially continuous layer (7); and washing liquid is supplied to the pulp layer and passed in several successive washing phases through different areas of the layer in such a way that the washing liquid gradually flows in the opposite direction compared with the flow direction of the pulp layer. According to the invention the washing liquid is divided in two or more partial flows which pass alternately through different washing phases in such a way that the washing liquid which in one phase has passed through the pulp layer flows past at least the washing phase preceding it in the flow direction of the pulp layer. The apparatus of the invention preferably comprises a rotating cylinder (1) the casting surface (2) of which serves as the liquid-pervious support surface for the pulp.

Abstract: A centrifugal apparatus for removing salts from herbicide solutions is provided comprising an outer cylindrical casing for enclosing a vertically rotatable spin basket. The outer cylindrical casing consists of a top wall, vertical side walls and a bottom wall with open passages for throughflow of spent filter media from said spin basket. The top wall supports a means for applying filter media against the internal walls of the spin basket, a means for spraying feed slurry against the internal walls of the spin basket, a means for spraying solvent against the internal walls of the spin basket, and a vertically rotatable plowing means. The vertical side walls support an internal upper collection trough for collecting liquid overflow from the spin basket when the spin basket is rotated, and with the bottom wall of the casing forms an internal lower collection chamber for collecting filtrate which flows through the spin basket when the spin basket is rotated.

Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises leaching a mixture of solids, water and contaminant in a three step process with solvents to obtain contaminated solvent and water and a mixture of decontaminated solids and solvent. The contaminant is stripped from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants.

Abstract: A device and method for scraping and collecting adsorbent from located areas on developed thin layer chromatography plates and extracting substances from collected adsorbent. The above functions can be performed without additional apparatus. The device is constructed of polypropylene to allow for easy use, manufacture and low cost. The shell surrounds a primary filtering and retaining material and a secondary filter. The adsorbent is removed from the thin layer chromatography plate via a scraping edge and collected by aspirating the adsorbent into the device where it becomes embedded in the primary filtering and retaining material. The device can then be separated to allow facile addition of a solvent to elute the sample out of the device free of adsorbent. The scraping process is improved as a result of the polypropylene contact with the plate, the collection process minimizes loss of removed adsorbent, and the elution/filtration allows easy recovery of developed samples.

Abstract: A method is provided for the purification and concentration of soy protein comprising mixing an aqueous solution including soy protein along with other water soluble moieties including sugars, salts, and phytins with a solid crosslinked polymer gel selected from the group consisting of N-substituted polyacrylamides and copolymers of N-substituted polyacrylamides; swelling the gel to absorb a portion of the water and other water soluble moieties including sugars, salts, and phytins from the aqueous solution by substantially maintaining the temperature of the gel at a preselected temperature below the lower critical solution temperature of the gel, to yield a concentrated soy protein solution; and separating the concentrated soy protein solution from the swollen gel. The concentrated soy protein solution may be repeatedly subjected to the gel treatment depending on the desired purity of the protein and the desired solids concentration.

Abstract: An apparatus for removing solid particles from cooling water having a tubular housing (1), a funnel-shaped trap sieve (4) attached to the inner housing wall with the tip facing in the flow direction, and a pressurized water sprayer (11). The sprayer includes a washer arm (14), concentrally rotatable about the downstream side (23) of trap sieve (4), and having at least one slit nozzle (15) directed toward the downstream surface (23). A suction tube (8) extends into a collecting chamber (10) of trap sieve (4). To prevent large particles from jamming rotating components, trap sieve (4) is cleaned by spraying water only against the downstream side. The tip of the sieve is defined by a cylindrical container (5) having a closed bottom (6). The intake end (9) of suction tube (8) extends into the container. Wash water is introduced into washer arm (14) through an inner end fixedly attached to a hollow flange (13) mounted on a rotary shaft (12) of pressurized spray apparatus (11).

Abstract: The invention is directed to a process for separating solid particles and/or liquid from a liquid suspension and/or purifying or leaching solid particles in a column containing a compacted bed, which comprises supplying a liquid suspension to said column while withdrawing liquid phase therefrom through a filter construction, disintegrating the washed compacted bed and removing the product of this disintegration, the washfront in the compacted bed being moved between two extreme limits in the compacted bed and to a wash column for use in this process.

Abstract: The invention relates to processes and apparatus for the elutriation of particles of a Ziegler-Natta type alpha-olefin polymerization catalyst, based on transition metal compound(s) and preferably also comprising magnesium compounds, by means of an elutriation liquid which is a non-polar liquid, for example a hydrocarbon chemically inert in relation to the catalyst. A preferred process comprises the following stages:preparation of a homogeneous suspension of the catalyst in the elutriation liquid, andelutriation of the catalyst by means of the suspension and the elutriation liquid in one or two elutriation columns (F1), (F2), separating the large and fine catalyst particles respectively.The apparatus comprises a tank (M2) for the preparation of the catalyst suspension and the elutriation column or columns (F1),(F2).

Abstract: Process for separation and purifying pigment suspensions and suspensions of pigment intermediates in a liquid by means of a membrane separation process, whereby the suspension to be treated is uniformly fed to and circulated through a microfiltration unit containing at least one semi-permeable membrane and the separated liquid flows off through the membrane as permeate which process comprises replacing the permeate gradually by a washing liquid that differs from the first liquid such that the total amount of washing liquid fed into the system is 1 to 15 times the total volume of the initial suspension, and separating the resultant suspension from the liquid by means of conventional filtration or drying apparatus. The process is particularly suitable for processing fine pigment suspensions often obtained in pigment synthesis.

Abstract: The invention relates to the purification of polymers, particularly resorbable polyesters, using shear fields produced mechanically or by fluid dynamics.

Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material adsorbing residual contaminants from the liquid fraction are adsorbed onto decontaminated solids to produce decontaminated liquids and contaminated solids.

Abstract: A semi-automated procedure for the isolation of Islets from the pancreata of different species is described. Pancreatic tissue first is treated to free the Islets from other pancreatic tissue. Enzyme digestion generally is used at least partially to achieve this effect. After separation of the Islet suspension from pancreatic debris, the suspension is subjected to multiple filtration to separate the Islets, which then are recovered from the filter.

Abstract: A counter-current process for purifying chemicals using cyrstal purification. The unit process has a purification and recovery section which contain substantially identical stages. In operation, the unit process purifies the chemical by utilizing sequential recrystallizer. The size and purity of the crystals increases from the last recrystallizer in the recovery section through each subsequent stage to the last recrystallizer in the purification section.

Abstract: A process for recovering succinimide lubricating oil additives from filter cakes formed during filtration of the additives employing a siliceous filter aid. The filter cakes are mixed with an aqueous solution of a base acting material having a pH above about 10, the mixture is held at a temperature above about 150.degree. F. and settled to separate an upper succinimide containing phase which is recovered.

Abstract: An apparatus for treating a fiber suspension, comprises a drum rotatably journalled to a stand and having an envelope surface to support a fiber web formed from the fiber suspension. A curved wall plate which is concave in the direction to the envelope surface of the drum is spaced from the envelope surface (and generally parallel thereto) to define a material space therebetween for said fiber web. The space includes an axial inlet gap and an axial outlet gap. The wall is continuous and encloses a major portion of the envelope surface of the drum and is arranged to move freely in the circumferential direction of the drum to compensate for radial alterations during adjustment of the distance of the wall from the envelope surface at one or more positions between the inlet gap and outlet gap. Adjustment devices cooperate with the wall for adjusting the distance of the wall from the envelope surface of the drum.

Abstract: An apparatus for concentrating a suspension consisting of a hollow cylinder in which one or more tubes of a constant outward diameter extend in axial direction, in the wall of each tube at least one filter being mounted forming the only direct connection between the interior of the tube and the interior of the cylinder. Two or more of such apparatus can be connected in series in order to form a cascade.

Abstract: A process is described for recovering phosphorus from pond sludge found in ponds located near phosphorus plants. An aqueous solution of the sludge, which has a phosphorus concentration in the range of 5% to 70% by weight, is heated at a temperature in the range of 165.degree. F. to 212.degree. F., preferably for about 1/2 hour to about 6 hours, washed with water at an elevated temperature, and then reheated. A phosphorus layer having an enhanced concentration of recoverable elemental phosphorus is formed as a result of this process.

Abstract: Water or sewage which contains sludges containing organic waste materials or waste materials which can be chemically precipitated are mixed with a flocculant consisting of a metal salt solution and are subsequently degasified. Thereafter, the pure water and organic sludge containing admixed metal hydroxide are separated from each other. The pH value of the sludge mixture is decreased until the metal hydroxides are dissolved as metal salts so that the organic sludge can be separated from the resulting metal salt solution. The metal salt solution is recirculated for re-use as a flocculant. Because the separated sludge still contains metal salts, it is treated with wash water and may possibly be further acidified. After the separation, the pH value of the wash water is increased to precipitate a metal hydroxide sludge, which is separated from the wash water and recycled to the degasified sewage.