Abstract: Environmentally friendly solvents used to dissolve or remove residues and/or substances from substrates wherein the residue and/or substance is contacted with a Generally Recognized As Safe solvent to dissolve the residue and/or substance in the solvent followed by the extraction of the residue and/or substance from the solvent such as by contact wiht carbon dioxide.

Abstract: A flotation method in which the gas bubbles for inducing flotation of the solids in the liquid are produced by a chemical reaction, for example a decomposition of hydrogen peroxide to oxygen and water, induced by catalytic action. The catalyst is on the walls of the flotation reaction and the substance to be flotated is introduced tangentially and caused to flow downwardly and thus upwardly in the reactor.

Abstract: A column of solvent containing foaming contaminants is provided. Gas is educted into the solvent in the column so as to generate foam in the column. The gas is educted into the column independently of the input flow of solvent into the solvent using a pumparound arrangement with the solvent. Foam generation continues so as to push the foam up in the column, wherein much of the solvent that is in the foam is allowed to drain back down into the column. The foam passes through concentrators which increase the residency time of the foam in the column to further dry the foam and to create larger bubbles. The drier foam is pushed out of the column and into a container. The foam is broken up into gas and the liquid foaming contaminants. The gas is recirculated for injection into the column even after foaming has stopped. The foaming contaminants are concentrated at the surface level of the solvent in the column. These contaminants are removed from the column.

Abstract: An improvement in a fractionation/flotation system for removing waste such as biosolids, nitrates or nitrites from a liquid containing same and an apparatus for separating liquid containing particles of varying mass or specific gravity. A reactor vessel 153 comprises a fractionation column 153a and a foam aggregation chamber 153b surmounting the column. Liquid containing the waste is pumped into the fractionation column 153a via a pump 105 and an outlet 159 that branches into a first inlet 163 and a second inlet 165. These inlets inject liquid into the fractionation chamber 153a at intermediate locations that are axially spaced apart, where the first inlet entry 163a is higher than the second inlet entry 165a. A waste reducing gas such as air, oxygen or ozone is injected into the second inlet immediately prior to insetting the liquid into the fractionation column 153a. Foam generated from the inlet liquid has biosolids adsorbed thereto and is collected within the aggregation chamber 153b for extraction.

Abstract: A grit-and-grease removal system includes a grit channel for degritting water by promoting settling of grit to the bottom of the channel, the grit being removed from the bottom of the channel by a traveling bridge-type grit removal device supporting a submerged grit pump. The system further includes an elongate grease channel arranged to receive degritted water from the grit channel, and having a plurality of grease skimmer pipes extending across the channel above the water level. The grease skimmer pipes are spaced apart along the length of the grease channel, and each grease skimmer pipe includes a plurality of fluid discharge orifices or nozzles spaced along the length of the pipe and oriented to blow fluid obliquely onto the water surface in the direction of a discharge end of the grease channel so as to move grease floating on the surface to the discharge end.

Abstract: A multi-stage apparatus and a process for recycling used engine coolant employs a combination of filtration, dissolved air floatation, centrifugation (hydrocyclone separation), semi-permeable nano filtration, reverse osmosis, and continuous deionization for separating ethylene glycol, with or without propylene glycol, and water from used engine coolant. The engine coolant is pre-filtered through a series of filters. The filters remove particulate contaminates. This filtered fluid is then subjected to dissolved air floatation and/or centrifugation to remove organic petroleum contaminants. Then, it is pressurized prior to being passed through semi-permeable nano filtration. The nano filtration separates the feed stream into a ultra filtration solution and a concentrated waste solution. The concentrate solution is returned to a centrifuged coolant tank for continuous circulation through the nano filtration device.

Abstract: A column of solvent containing foaming contaminants is provided. Gas is educted into the solvent in the column so as to generate foam in the column. The gas is educted into the column independently of the input flow of solvent into the solvent using a pumparound arrangement with the solvent. Foam generation continues so as to push the foam up in the column, wherein much of the solvent that is in the foam is allowed to drain back down into the column. The foam passes through concentrators which increase the residency time of the foam in the column to further dry the foam and to create larger bubbles. The drier foam is pushed out of the column and into a container. The foam is broken up into gas and the liquid foaming contaminants. The gas is recirculated for injection into the column even after foaming has stopped. The foaming contaminants are concentrated at the surface level of the solvent in the column. These contaminants are removed from the column.

Abstract: An integrated apparatus that contains both the gravity settling mechanism and the dissolved-air floatation (DAF) mechanism in a compensating manner is provided. The said apparatus comprises a gravity settling chamber (34), a DAF chamber (42), a chamber connection channel (22), an air-dissolving device (38), a means for collecting treated water (24), and a water level control device (16). During treatment, heavy solid particles in water or wastewater can be quickly removed by gravity settling, while the remaining light solid particles and/or oil can be quickly removed by DAF. Thus, the apparatus of this invention is more effective and efficient compared with conventional clarifiers that employ only one clarification mechanism. Therefore, the apparatus of this invention is more compact and can achieve better effluent quality.

Abstract: The invention relates to a process for the reprocessing respectively purification of aqueous solutions of a tertiary amine oxide, particularly of process waters, e.g. used precipitation baths, which occur during the production of cellulosic moulded bodies, comprising the separation of turbidifying agents and solid impurities from the solution. The process in accordance with the invention is characterised in that the turbidifying agents and impurities are at least partly separated by means of a flotation process.

Abstract: A method and apparatus for mixing a first material and a second material is described in which the first material comprises a mixture of two or more dissimilar components which it is desired to separate. The method and apparatus involve forming an intimate mixture of the two materials prior to separating the two dissimilar components of the first material. The apparatus involves the use of a hydrocyclone for aerating or gasifying a feed stream, such as waste water containing oleophilic residue or food residue, to entrain the particles of residue within the air or gas bubbles prior to separating the oil or food residues from the carrier material, typically water. Instead of using the hydrocyclone as a separator, it is used as a mixer which provides surprising results and facilitates separation of the aerated components.

Abstract: A process of environmental recovery in urban regions that acts along the entire watercourse mesh of an urban region, from the canalized domestic course of sewerage systems to the urban sections of riverbed, including the following stages: from the domestic section, such as a sewerage gallery, to promote a micro application of floating or coagulating material in the watercourse to be treated, whether rainwater or sewer matter; followed by micro flocculation, so as to promote an aggregation of particles in suspension downstream, defining flakes of greater dimensions; submit those larger aggregated particles in suspension downstream in this domestic watercourse to, at least one step of dissolution and air injection, causing a micro floatation of such aggregated particles; allowing a micro aggregation of the floating material to occur downstream, which will be removed from this domestic course before it reaches a streamlet or even a river effluent; next, after the flow of water submitted to a micro treatment is t

Abstract: A process and system for recovering fine coal having a size at or below 400 mesh. The process and system includes a series of cyclone separators, vibratory separators, centrifuges and a flow path to clean, recover and dewater fine coal having a nominal size of 3 mm down to 400 mesh or below. The process and system includes the use of commercially available components arranged in a novel manner to efficiently recover fine coal for use in various energy supplying systems.

Abstract: A grit-and-grease removal system includes a grit channel for degritting water by promoting settling of grit to the bottom of the channel, the grit being removed from the bottom of the channel by a traveling bridge-type grit removal device supporting a submerged grit pump. The system further includes an elongate grease channel arranged to receive degritted water from the grit channel, and having a plurality of grease skimmer pipes extending across the channel above the water level. The grease skimmer pipes are spaced apart along the length of the grease channel, and each grease skimmer pipe includes a plurality of fluid discharge orifices or nozzles spaced along the length of the pipe and oriented to blow fluid obliquely onto the water surface in the direction of a discharge end of the grease channel so as to move grease floating on the surface to the discharge end.

Abstract: Apparatus and a process for separating impurities from a suspension in a flotation cell, including an aeration device for aerating a liquid with a gas until the liquid is saturated. An expansion device expands the liquid saturated with gas to form gas bubbles in the liquid. An addition device adds the liquid containing gas bubbles to the suspension in the flotation cell.

Abstract: The removal of inks from a pulp fiber slurry is accomplished by use of a combination of (1) a polyester obtained through reaction between di and/or tricarboxylic acids and/or anhydrides thereof and a polyalkylene glycol or one or more alkylene oxides, (2) a first deinking agent which is an alkoxylated hydrophobic base, e.g. an alcohol, amine, acid, dimer acid, salts thereof, or the like, and (3) a second deinking agent which is a second alkoxylated hydrophobic base having a cloud point about 2 to 20° lower than the cloud point of the first deinking agent. Use of the three component combination allows an improved foam profile allowing longer continuous operation or one or more of a reduction in total chemical demand, optical bleach demand, and stickies.

Abstract: The invention is directed to a method for flotation separation. The method has the steps of feeding an influent stream containing liquids and solids to a vessel, while removing clarified liquid at the same time as the feeding process. The method employs a step for emptying the solids from the vessel based on the solids having formed a float blanket of a predetermined depth. The solids are removed from the vessel through a bottom nozzle as opposed to being skimmed off the top surface with mechanical separators. The depth of the float blanket can be monitored. Once it is determined that the float blanket has reached the predetermined depth, the feed to the vessel is stopped and the vessel is emptied of liquids and solids through a suitable outlet other than the feed inlet, by an arrangement of valves and lines.

Abstract: An apparatus and method for separating microalgae from water without rupturing cells. The method comprises the steps of flocculation, flotation and dehydration. Microalgae suspension from a reservoir is passed to a mixer unit where flocculation is carried out, using modified starch or other flocculating agents. The suspension is then directed to a flotation column. Dissolved gas in water is transferred to the flotation column through a disperser. A layer of foam containing microalgae is formed on the liquid layer in the column, which can be skimmed off through an overflow outlet. The flotation column is a telescopic column of adjustable height, which enables the position of the overflow outlet to be aligned with the level of the foam layer for efficient foam removal. Foam containing microalgae is then passed to a filtration unit for cloth filtration, followed by drying in a drying chamber.

Abstract: A method for treating wastewater includes the steps of collecting wastewater in a tank and transfering the wastewater between the tank and an ozone system in a batch process or as a continuously transfering process. The oxidation of the wastewater is monitored and the wastewater is either re-used or discharged when the oxidation amount has dropped to a predetermined level. In a second embodiment, the wastewater is pre-treated by aeration. This causes contaminates to float on the surface of the wastewater and the contaminates are removed by skimming or decanting. The pre-treatment substantially reduces the power requirements of the ozone system.

Abstract: A system for facilitating the separation of materials dissolved from a fluid. The system includes an apparatus for separating proteins and other organics from fluid is provided. The apparatus includes a column having an interior chamber extending between a first end and a second end of the column. The apparatus also includes an inlet tangentially positioned relative to the interior chamber, so as to induce a cyclonic flow as fluid enters into the interior chamber. The apparatus further includes an injection port through which bubbles may be introduced into the fluid flow within the interior chamber. As the bubbles ascend materials dissolved in the fluid adhere to the bubbles an get carried upward towards the surface level of the fluid. Foam generated by the coalescing bubbles may be collected in a trough provided about the first end of the column and may be directed thereinto by a deflector.

Abstract: Powdered compositions comprising in admixture inorganic salts and silica gel, and optionally a fragrance additive, are disclosed. The novel compositions are useful in absorbing and deodorizing liquid waste and for removing such waste from irregular surfaces, such as textiles and carpeting, as well as from smooth hard surfaces. The compositions are effective in absorbing liquid biohazards, such as blood, vomit, urine, and other body fluids. For this application, a halogen-containing compound, such as sodium hypochlorite or calcium hypochlorite is preferably included in the composition. The mixtures can also be utilized for the absorption of oil-based spills and hydrocarbons and are also effective in removing moisture and malodors associated with pet urine and other moisture-related stains encountered in the home. When applied to liquid wastes, the absorbent properties of the compositions contain the spill, creating a solid cohesive matrix that allows for easy disposal.

Abstract: A column of solvent containing foaming contaminants is provided. Gas is educted into the solvent in the column so as to generate foam in the column. The gas is educted into the column independently of the input flow of solvent into the solvent using a pumparound arrangement with the solvent. Foam generation continues so as to push the foam up in the column, wherein much of the solvent that is in the foam is allowed to drain back down into the column. The foam passes through concentrators which increase the residency time of the foam in the column to further dry the foam and to create larger bubbles. The drier foam is pushed out of the column and into a container. The foam is broken up into gas and the liquid foaming contaminants. The gas is recirculated for injection into the column even after foaming has stopped. The foaming contaminants are concentrated at the surface level of the solvent in the column. These contaminants are removed from the column.

Abstract: A protein skimmer for removal of protein contaminates from protein contaminated water. An injector is used for spraying protein contaminated water into a water bubble chamber. The spraying motion causes bubble generation in the water bubble chamber. Contaminates in the water attach themselves to the bubbles and rise to the surface of the water as foam. A hollow foam riser is attached to the top of the water bubble chamber and provides an exit pathway for the contaminated foam. As foam is generated, it rises through the foam riser and carries with it contaminates. A foam collection cup is attached to the top of the foam riser and collects the contaminated foam. Consequently, the water left behind in the mixing chamber is substantially more pure. The substantially more pure water exits the mixing chamber through a purified water exit aperture.

Abstract: A system for removing bleed-through contaminants from OCC fiber pulp includes a plurality of primary flotation cells, with each primary flotation cell having an inlet, an accept outlet and a reject outlet. The inlet and the accept outlets of the plurality of primary flotation cells are coupled together in a series configuration. The reject outlets are coupled together in parallel. A secondary flotation cell has an inlet, at least one accept outlet and a reject outlet. The secondary flotation cell inlet is fluidly coupled with the reject outlet of the primary flotation cells. A water clarifier has an inlet, a clarified water outlet and a sludge outlet. The inlet is connected with the reject outlet of the secondary flotation cell.

Abstract: A flotation device for separating materials or mixtures of materials from suspensions includes a reaction and mixing space (18) with eccentric inlet (16) for the mixture of suspension particles with gas bubbles and for further transport into at least one centrally arranged vertical suspension distribution tube (26), wherein the suspension distribution tube (26) and the clarified fluid collecting tube (48) are arranged adjacently, the plates (30) surround the suspension distribution tube (26) and the clarified fluid collecting tube (48) in an annular manner; and every second annular plate space (31) between adjacent plates (30) is connected to the suspension distribution tube (26) and every other space (31) between plates is connected to the clarified fluid collecting tube (48), so that the flow takes place out of one space (31) between plates from the inside towards the outside to the separating space (32), and subsequently into an adjacent space (31) between plates from the outside towards the inside.

Abstract: Process and device for the flotation of contaminates out of an aqueous fibrous suspension using a foam. The process includes creating the foam, introducing the fibrous suspension into the foam, transferring contaminates from the fibrous suspension to the foam, and removing some portion of the fibrous suspension from the foam as an accepted stock. The device includes a liquid containing area, a mechanism for introducing a gas into the liquid containing area, and a mechanism for introducing the fibrous suspension into a foam containing area arranged to be adjacent the liquid containing area.

Abstract: A process for separation of an oil-containing aqueous emulsion includes mixing the oil-containing aqueous emulsion with carbon-dioxide and subjecting the emulsion and carbon dioxide for a specified time within an autoclave to an elevated pressure and an elevated temperature. A rising stream of bubbles is formed within the autoclave by suddenly relieving the pressure within the autoclave with the rising stream of bubbles serving to separate the oil-containing aqueous emulsion into an oil-rich phase and an oil-depleted emulsion. The oil depleted emulsion is transferred to a segrating tank. At least a fraction of the oil-depleted emulsion within the segregated tank is subjected to ultrafiltration to separate the fraction into a permeate and a retentate.

Abstract: An apparatus for facilitating the separation of organic materials from a fluid and for promoting the gas exchange from the fluid is provided. The apparatus includes a column having an interior chamber extending between a first end and a second end of the column. A plenum is situated circumferentially about the second end of the column. At a junction between the plenum and the interior chamber, an annulus is provided to permit the plenum to be in fluid communication with the interior chamber. An external port is provided for communication with the plenum. A column of media may be provided in the interior chamber through which fluid to be treated may flow.

Abstract: A method and apparatus for biologic treatment of wastewater using both aerobic and anoxic phases. The flow of influent entering the reactor tank is slowed by a conical influent structure and discharged against the bottom of the reactor tank, so that the influent flows outwardly under a sludge blanket near the bottom of the tank without disrupting the blanket. The sludge blanket acts as a cap which prevents the influent from flowing directly to an outflow opening during decanting of the tank. The sludge blanket is dispersed and mixed in the tank during the aerobic and anoxic treatment phases. The invention also provides for treatment of manure-laden wastewater discharged from a confined animal facility, such as a feed yard, pig farm or dairy. The manure solids are separated from the wastewater flow before the wastewater enters the reactor tank. The wastewater is returned to the facility for reuse, and the manure solids can be disposed of in dry form as fertilizer.

Abstract: A multi-stage apparatus and a process for recycling used engine coolant employs a combination of filtration, dissolved air floatation, centrifugation (hydrocyclone separation), semi-permeable nano filtration, reverse osmosis, and continuous deionization for separating ethylene glycol, with or without propylene glycol, and water from used engine coolant. The engine coolant is pre-filtered through a series of filters. The filters remove particulate contaminates. This filtered fluid is then subjected to dissolved air floatation and/or centrifugation to remove organic petroleum contaminants. Then, it is pressurized prior to being passed through semi-permeable nano filtration. The nano filtration separates the feed stream into a ultra filtration solution and a concentrated waste solution. The concentrate solution is returned to a centrifuged coolant tank for continuous circulation through the nano filtration device.

Abstract: A flotation plant comprises air supply means with which air bubbles can be supplied to a basin to which untreated water is supplied so as to cause flakes suspended in the untreated water to float by aid of the air bubbles; the air supply means includes strip- or plate-shaped aeration means having perforated membranes and to be installed in the bottom region of said basin.

Abstract: An apparatus is disclosed which allows the hydrate formed in the hydrate formation region of a desalination fractionation apparatus to be cooled as it rises in the apparatus. This has the beneficial effect of increasing its stability at lower pressures and reducing the depth at which the hydrate will begin to dissociate. The present invention provides for more efficient management of the distribution of thermal energy within the apparatus as a whole by controlling the flow of water through the system—particularly residual fluids remaining after hydrate forms—such that it is substantially downward through the fractionation column and out through a lower portion thereof. Hydrate thus separates from the residual fluid at or nearly at the point of formation, which helps keep the hydrate formation region of the apparatus at a temperature suitable for the formation of hydrate and improves efficiency.

Abstract: A dissolved gas flotation apparatus and process for removing oils and other contaminants from produced water generated in the production of crude petroleum and natural gas. The invention is particularly designed for offshore applications, where space is limited and natural gas is readily available. The invention includes a vessel for receiving and maintaining a liquid level therein and a circulating pump for introducing tiny flotation gas bubbles into the vessel. Natural gas is used as a blanket gas for the vessel and as a source of gas fed into the pump, wherein the gas is mixed with the pumped liquid. The liquid/gas mixture is transferred into the vessel, wherein the gas releases from the liquid, thereby forming tiny, finely dispersed gas bubbles.

Abstract: An apparatus for recovering a desired fraction of a raw material bearing the desired fraction has a vessel or cell defining a treatment chamber therein, with an inlet into the chamber for introducing a slurry of raw material to be treated into the chamber. An attrition zone is defined in a portion of the chamber proximate the inlet in the flow path of material introduced into the chamber, the particles being caused to impact against each other in the attrition zone to cause attritioning thereof. A floatation zone is defined in a distal portion of the chamber, in flow communication with the attrition zone, in which attritioned particles from the attrition zone can be contacted with gas bubbles to form a froth phase separated from the slurry by a slurry-froth interface such that the desired fraction is either selectively taken up into the froth phase by the gas bubbles or selectively left behind in the slurry. An outlet from the chamber for the froth phase is present.

Abstract: The invention relates to a process for the reprocessing respectively purification of aqueous solutions of a tertiary amine oxide, particularly of process waters, e.g. used precipitation baths, which occur during the production of cellulosic moulded bodies, comprising the separation of turbidifying agents and solid impurities from the solution. The process in accordance with the invention is characterised in that the turbidifying agents and impurities are at least partly separated by means of a flotation process.

Abstract: Coagulated particles having a low water content are separated and recovered from an emulsified dispersion of fluorine-containing polymer particles. A solid-liquid separation method comprising: a step for adding a coagulant in an emulsified dispersion of fluorine-containing polymer particles to coagulate the fluorine-containing polymer particles with stirring and obtain a slurry of coagulated particles, a step for filtrating the slurry, and a step for pressing the obtained cake. It is preferable to continuously carry out the filtration step and pressing step with a filter press or a belt press. Also a washing step may be provided after the filtration step.

Abstract: The invention comprises, in one form thereof, a method of removing wax from recycled cellulosic fiber. The cellulosic fiber is pulped in a pulper to a suspension with a consistency of less than about 10% by weight. The suspension is then screened to remove coarse and fine contaminants. The screened suspension is diluted to a consistency of less than about 3% by weight. The wax is removed from the diluted suspension using a froth flotation device. The suspension is then washed and/or thickened.

Abstract: A protein skimmer for removal of protein contaminates from protein contaminated water. An injector is used for spraying protein contaminated water into a water bubble chamber. The spraying motion causes bubble generation in the water bubble chamber. Contaminates in the water attach themselves to the bubbles and rise to the surface of the water as foam. A hollow foam riser is attached to the top of the water bubble chamber and provides an exit pathway for the contaminated foam. As foam is generated, it rises through the foam riser and carries with it contaminates. A foam collection cup is attached to the top of the foam riser and collects the contaminated foam. Consequently, the water left behind in the mixing chamber is substantially more pure. The substantially more pure water exits the mixing chamber through a purified water exit aperture.

Abstract: Flotation apparatus (1) for the purification of polluted water, comprising a flotation vessel (3) having an inlet means (23) for supplying polluted water to said vessel, an assembly (41) of spaced elements (43, 65) defining passages for the flow of water through said elements, and outlet means for surface sludge (15, 17) and outlet means (39, 45; 57, 61) for treated water, further comprising flow directing means for forcing the incoming polluted water to reach a level above said assembly (41) and to flow downwardly through said assembly and towards said treated water outlet means (39, 45; 57, 61); and a process for the purification of polluted water by flotation performed in such apparatus.

Abstract: A method of purifying a flue gas desulfurization aqueous waste slurry containing calcium-sulfur salts and residual solid grits, fly ash, carbon and oils by supplying the aqueous waste slurry to a screening station to remove the grits, passing the grit-free aqueous waste slurry to a magnetic separator to remove fly ash components, and transferring the aqueous slurry to a floatation cell to remove carbon and oils therefrom. A purified aqueous slurry of calcium-sulfur salts is removed from the floatation cell which can be used in producing quality plaster, wallboard, or feedstock in producing &agr;-hemihydrate gypsum.

Abstract: The process targets the removal of interfering materials from an aqueous fibrous material suspension, especially if this is produced from recycled paper. Thereby interfering materials, such as printing ink particles, small synthetic particles, or sticky contamination, are eliminated by flotation in a particularly advantageous manner. In accordance with the invention, the combination of low-intensity and high-intensity flotation is undertaken, whereby the low-intensity flotation generally works in the gravitational field and the high-intensity flotation in a centrifugal field.

Abstract: A protein skimmer for removal of protein contaminates from protein contaminated water. An injector is used for spraying protein contaminated water into a mixing chamber having a water bubble chamber. The spraying motion causes bubble generation in the water bubble chamber. Contaminates in the water attach themselves to the bubbles and rise to the surface of the water as foam. A hollow foam riser is attached to the top of the mixing chamber and provides an exit pathway for the contaminated foam. As foam is generated, it rises through the foam riser and carries with it contaminates. A foam collection cup is attached to the top of the foam riser and collects the contaminated foam. Consequently, the water left behind in the mixing chamber is substantially more pure. The substantially more pure water exits the mixing chamber through a purified water exit aperture.

Abstract: Apparatus and methods for material separation consisting of a cyclone aerator which can enhance contact between contaminated water and air, or a oxidant gas, and can enhance the contact and attachment between particulates contained in the suspension and bubbles formed in the cyclone aerator. One embodiment comprises a plurality of plates positioned in a spaced relationship to one another within a jacketed tube. The plates are arranged in a distinct, non-radial orientation extending partially towards the center of the jacketing tube to define a cylindrical chamber within a center of the plates and an annular cylindrical chamber between the plates and the jacketing tube. A suspension is introduced into the cylindrical chamber tangentially through a feed line proximate or integral with a jacketing tube top of said jacketing tube to develop a swirling flow pattern of the suspension within the cylindrical chamber.

Abstract: The flotation process for separating particulate impurities from fibrous suspensions in a flotation tank. Upon or after entry into the flotation tank, the fibrous suspension added to the flotation tank may be mixed with a portion of the suspension already in the flotation tank. The portion of the suspension already in the flotation tank may be drawn into the added suspension. After mixing, the mixed suspensions enter a mixing element. The mixed suspension is expelled into the flotation tank and a circular flow pattern is generated within the flotation tank as a result. A flow speed may be limited at a top end so that an optimal mixing with the gas bubbles required for flotation may occur with a desired energy savings.

Abstract: Sequential DAF apparatus and methods providing zero pool and nonmechanical waste material removal are disclosed which include a number of floatation tanks each arranged to operate either independently or sequentially, each tank has a conical shaped bottom with a centrally located port at the lowest vertical position of the tank, each tank is fitted with a number of valves and plumbing which allows an operator to fill each tank with waste water charged with dissolved air through the central port which is then retained during a floatation period to allowed waste material to separate from clarified water in the tank. Clarified water and waste material is removed from the bottom of the tank through the central port. Water clarity sensors are positioned in the tank near the central port. A final rinsing step may be included to assure all floated material is removed from the tank before refilling.

Abstract: A superb centrifugal flotation cell with a rotating feed, is provided for use in an effective separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary pipe and a rotating feed line comprising a centrifugal rotating downfeeder. The slurry is centrifugally discharged from the rotating downfeeder into the flotation chamber where the slurry is separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles for further processing.

Abstract: A treatment process for recovering protein, fatty and water component products from a float material produced by a waste water treatment system, wherein the protein and fatty components possess improved stability and are suitable for further processing for inclusion in various products, such as animal feed. The recovered water component can also be further processed before discharge into a sewer system.

Abstract: A mixing device in the form of a centrifugal pump is used to mix gas (typically air) with liquid (typically effluent water, dispersion water, or waste paper pulp suspension, etc.). The pump is provided with a common inlet conduit for both the liquid and the gas so that liquid and gas flow freely and in an arbitrary ratio into the pump, that is there is no controlling or adjusting of the flows. The gas is allowed to either dissolve in the liquid or be mixed as small bubbles with the liquid, and any surplus gas is separated from the mixing device (e.g. by holes in the pump impeller leading to a rear portion of the pump which is attached to a vacuum source, such as a liquid ring pump). The liquid and gas dissolved therein, and small bubbles mixed therein, are discharged from the mixing device at a pressure that is raised from the inlet pressure, due to the action of the impeller, which pressure development enhances the dissolution of gas in the liquid.

Abstract: An apparatus for treating contaminated soil is disclosed. The apparatus includes a reactor vessel for holding a volume of water which is subdivided into a first chamber and a second chamber. The chambers are in fluid communication and are partially separated by a baffle. A soil conveyor is provided for conveying a supply of the contaminated soil to the first chamber. A gas supply directs a supply of pressurized gas into the first chamber, thereby creating a turbulent mixture of soil and water in the first chamber to effect segregation of the soil into a substantially small particle size first fraction and a substantially large particle size second fraction. The reactor vessel includes a first outlet located in a lower portion of the second chamber for withdrawing a slurry comprising the second soil fraction from the reactor vessel. The lower portion of the second chamber may be funnel-shaped to help direct the mixture of soil and water toward the first outlet.

Abstract: A column of solvent containing foaming contaminants is provided. Gas is injected into the solvent in the column so as to generate foam in the column. Foam generation continues so as to push the foam up in the column, wherein much of the solvent that is in the foam is allowed to drain back down into the column. The drier foam is pushed out of the column and into a container. The foam is broken up into gas and the liquid foaming contaminants. The gas is vented and recirculated for injection into the column for foaming purposes. A portion of the liquid in the container is recirculated as a spray, which spray breaks up the foam. Another portion of the liquid in the container is recirculated into the column as reflux. Another portion of the liquid in the container is removed from the system in order to remove foaming contaminants therefrom.

Abstract: A reverse osmosis process for treating a phenolic stripped sour water stream containing soluble and insoluble contaminants is provided. Prior to passage through a reverse osmosis membrane, the phenolic stripped sour water stream is cooled, subjected to air flotation and filtered through a sand filtration system to remove insoluble contaminants, and passed through a water softener to remove divalent and trivalent metal cation contaminants. The pH of the stream is adjusted prior to the water softener, and again prior to the reverse osmosis membrane, to stabilize the solubility of soluble organic contaminants present within the stream.