Abstract: The present invention concerns a reactor for removing impurities from a liquid, in particular for de-inking, including a tank (1) within which the liquid to be purified together with a gas or air is introduced (2-3); a drain of the purified accepted through an outlet (7) of said tank (1); inlets (8-11, 9-12, 10-13) at different heights of the tank (1) connected to said purified liquid outlet (7) together with the inlet of gas or air; a rotating shaft (18) inside the tank (1) carrying blades (20, 21, 22, 23) at the different heights of the tank within which the liquid together with gas or air is introduced; the blades (20, 21, 22, 23) have progressively increasing heights when moving towards the lower portion of the tank (1). The invention also concerns the method embodied by the above-described reactor.

Abstract: Raw feed water is continuously clarified at a large throughput rate in a single, shallow tank using a flotation process carried out simultaneously in multiple sectors of the tank. Raw water feeds into a rotating trough. A fixed manifold system in the trough dispenses pressurized water containing dissolved air to release microscopic air bubbles. A set of headers each radially extend outwardly from the rotating trough. Each header distributes water and bubbles to a sector of the tank with a net zero velocity. A set of rotating extractors each receive clarified water from the bottom of a preceding sector. A set of scoops skim floated sludge from the water in the tank. The sludge is lifted, as by the rotation of the scoop and/or by a pumped conduit, over the rotating trough to a sludge outlet pipe. In one form the scoop has at least two blades each with an eccentrically located, radially extending compartment that receives, lifts, and then dumps the skimmed sludge as the scoop rotates about its axis.

Abstract: A process is described for removing chlorides from crude oils, including heavy oils and bitumens. The process steps comprise (1) mixing a non-ionic surfactant with the crude oil, (2) bubbling a gas into the crude oil-surfactant mixture to form a froth, (3) centrifuging the frothed mixture to obtain a chloride containing sediment and an oil product of reduced chloride content and (4) collecting the oil product.

Abstract: Aggregate is separated from sludge consisting of, what is called, "the residual raw concrete" remaining in a raw concrete mixing truck from which raw (uncured) concrete has been discharged, and waste water resulting from washing the mixing truck. The sludge is stored in a pretreatment vessel. Then, air is forced into the sludge to form bubbles. A chemical admixture in the sludge is allowed to adhere to the bubbles, and an admixture coating within the sludge is removed, thereby promoting the hydration of the cement. Subsequently, the resultant sludge is dehydrated to obtain a dehydrated cake of high hardness. Powder formed of the same quality of the cake is spread over the cake, which is then cured for a few hours. The resultant cake is then crushed so that granular aggregate can be formed.

Abstract: A water treatment system and process separates contaminants from water by flotation, by forming a removable floating scum of impurities utilizing a bubbling process, by filtering out suspended solids, by stripping dissolved impurities from the water with air, by oxidizing organic compounds, by adsorbing organic compounds, and finally, by disinfecting. Utilization of the disclosed process and system will transform contaminated water into an environmentally suitable state.

Abstract: Apparatus and method is described for dewatering sludge obtained from a flotation tank, which efficiently handles the sludge and avoids the need for adding polymers to reflock the sludge. The sludge dewatering portion includes a conveyor (40, FIG. 1) which has an uppath portion (42) that receives sludge that is dropped over a cliff (32), the conveyor having a downpath portion (44) which firmly compresses the sludge as it continues to move along the conveyor. The conveyor preferably extends at an incline to the horizontal with the downpath portion lying higher than the uppath portion, and with a fluid conduit lying under the conveyor and carrying liquid downwardly along the incline to a pump (74) that pumps the liquid along a return conduit (80) back to the flotation tank. One conveyor includes an elongated shaft (50, FIG.

Abstract: A dissolved air flotation (DAF) system and method for gas-liquid contacting operations. A mixture of untreated liquid and liquid saturated with dissolved air is passed through a series of upward deflecting screens placed across the flowpath in a rectangular tank. Microbubbles of air released from the mixture produce a buoyant force which carries contacted particles to the surface. Floated particles released from the microbubbles form a sludge which is supported above the surface of the mixture by a layer of air derived from the microbubbles. A top layer of the sludge is skimmed off according to a predetermined residence time of sludge at the surface. Liquid containing dissolved air is also introduced downstream of each deflecting screen to enhance flotation and clarification.

Abstract: An improved method for processing multiple small batches of waste material from different collection sites is provided. The method uses an apparatus designed to process small batches of waste material from a collection site, such as a septic tank, into waste water and sludge material. Using the apparatus, the waste material first undergoes oxidation with an oxidizing agent and separation with a flocculating agent. After the oxidizing and separating steps are completed, the waste water is then drained from the apparatus and returned to the collection site. The sludge material produced is then transported to a second collection site. The waste material from the second collection site is then added and mixed with the sludge material produced from the first small batch of waste material. The new waste material is then oxidized and separated into waste water and sludge material. The waste water is then drained from the apparatus and deposited into the collection site.

Abstract: A process is provided for clean-up of soils contaminated with highly viscous coal tar and/or petroleum derived organics. This new invention is based on application of the modified Clean Soil Process integrated with modified thermal desorption technology. This new invention utilizes the unexpected advantages of integration of the Clean Soil Process and conventional thermal desorption which cannot, when applied separately or in sequence (Clean Soil Process followed by Conventional Thermal Desorption), furnish satisfactory clean-up, but when integrated have the capacity to clean the most difficult contaminated soils (including soils contaminated by manufactured gas plants) to about 100 ppm, or less of total soluble organics and less than 3 ppm of PAH's.

Abstract: Apparatus for removing volatile contaminant compounds from a liquid by sparging a cleaning gas therethrough comprises a volatile contaminant extraction assembly including a hollow porous tube surrounded by an outer jacket defining a gas plenum between the jacket and the porous tube; a contaminated liquid feed assembly including a nozzle for injecting liquid into the porous tube in a spiraling flow pattern around and along the porous tube; a gas-liquid separator assembly including a nonporous degassing tube coaxially aligned with and connected to the porous tube, a separator tube coaxially aligned with and connected to the degassing tube and flaring outwardly in diameter from the degassing tube, and a gas duct coaxially aligned with the separator tube and extending into the separator tube to collect and convey cleaning gas therefrom; a clean liquid collection assembly; and a gas discharge assembly.

Abstract: The parameters of a gas-liquid contact apparatus for the removal of a component of a gas stream in which an impeller-apertured shroud combination is immersed in a liquid phase to which the gas stream is fed at a gas flow rate of Q. The structural and operating parameters of the apparatus are quantified to provide a Shear Effectiveness Index (SEI) value of from about 1 to about 10 and an Effective Shear Index (ESI) value of from about 1 to about 2500.

Abstract: An apparatus and a process for separating substances from an influent fluid by means of dissolved-gas flotation, in which a flotation tank has at least one fixed fluid inlet for the influent fluid and at least one mixture inlet for a fluid-gas mixture. Associated with the mixture inlet is a depressurization element for at least partial decompression of the fluid-gas mixture directly into the flotation tank, with the depressurization element being arranged essentially below the influent liquid inlet. The essential advantages of the invention are that, owing to the direct decompression directly below the flow of the influent liquid, a more efficient flotation process is effected. The losses after decompression can be kept low, and the gas bubbles formed can be immediately employed for flotation.

Abstract: An apparatus for gas bubble flotation comprises an angular flotation tank (1a, 1b), at least one liquid inlet (2a, 2b) for a liquid containing suspended matter and a liquid admixed with gas bubbles, in which apparatus at least one liquid inlet (2a, 2b) is arranged in the vicinity of at least one flotation tank corner. Preferably, the flotation tank has a square cross section. This permits optimal utilization of the available space, and results in a continuously decreasing flow velocity and thus an improved flotation effect.

Abstract: Components, usually but not exclusively gaseous components, are removed in a liquid medium from gas streams and chemically converted into an insoluble phase or physically removed. Specifically, hydrogen sulfide may be removed from gas streams by oxidation in aqueous chelated transition metal solution in a modified agitated flotation cell. The same principal may be employed in other procedures in which a gaseous phase is dispersed in a liquid phase to effect an interaction between components present in such phases. A gas-liquid contact apparatus, generally a combined chemical reactor and solid product separation device, comprising such modified agitated flotation cell is also described. In order to effect mass transfer and rapid reaction gas bubbles containing hydrogen sulfide and oxygen are formed by rotating an impeller at a blade tip velocity of at least about 350 in/sec. to achieve the required shear.

Abstract: A method for separating water soluble, polymerizable resin from rinse water containing such resin which comprises adjusting the specific gravity of the rinse water so that the resin floats on the surface of the rinse water. The resin is then removed and purified for reuse.

Abstract: A simplified single cell apparatus and method for removal of suspended impurities in liquids using gas flotation and filtration is provided wherein the method and apparatus are preferably directed to induced gas flotation separation of suspended impurities in combination with a filter media for filtration removal of remaining suspended impurities. A filter media is contained within the single cell apparatus such that liquid exiting the vessel must pass through the filter media after having been subjected to flotation treatment.

Abstract: A water purification plant and method for purifying liquid by flotation clarification, in which pollution particles, or impurities dissolved in the liquid and brought into a particle form by flocculation chemicals, are separated from the liquid and led onto a surface of the fluid to form a bed of slurry. The slurry bed is led away into a sewer system and the purified liquid is led through an intermediate bottom of a clarification basin into a lower space of the clarification basin or directly away for additional purification or consumption. The intermediate bottom of the clarification basin is provided with elements affecting the flow such that the flow resistance occurring through the intermediate bottom is at its largest at the final end of the clarification basin and the flow resistance decreases towards the initial end of the clarification basin, whereby the entire area of the clarification basin has substantially the same, and uniform, flow volume.

Abstract: An apparatus for mixing a gas with a liquid and for dissolving the gas in the liquid comprises a throttled section (12) formed in a fluid flow passage, a gas inlet (18) provided slightly downstream of the throttled section (12), a widened section (16) which is continuous with the throttled section (12), a mixing section (20) provided downstream of the widened section (16), for mixing the gas introduced from the gas inlet (18) with the liquid in the fluid flow passage, and a nozzle section (24) provided on the outlet of the mixing section (20) for outputting the liquid with the gas dissolved therein. The gas is dissolved in the liquid in the mixing section by pressurizing the liquid in the mixing section. The apparatus is useful for dissolving ozone into a liquid, for dispersing bubbles in a liquid and for floating small particles in a liquid.

Abstract: A method for producing substantially ink-free pulp from recycle printed paper comprising first pulping the recycle paper in a hydrapulper with at least water and an agglomerating agent thereby producing a pulp. Ink particle agglomerates in the pulp are then removed by screening the pulp through at least one screen and by cleaning the pulp in a cyclone cleaner. Pulp together with small ink particles that escape the prior separation stages is then conducted from the cyclone cleaner through a standpipe at a consistency of about or less than 1% where particles of ink associate with small air bubbles and are elevated to the surface of the pulp where they accumulate as a froth which may be removed by overflowing.

Abstract: The method serves for the separation of solid materials out of a suspension and is, as a rule, implemented as a floatation method. The suspension (S) to be clarified is added tangentially from the outside at the periphery of a substantially cylindrical clarification volume (1). Damaging flow phenomena, such as for instance turbulence, are removed to the largest possible extent by flow means (2) which are applied prior to the entry of the suspension into the clarification volume so that an optimal flow takes place in the clarification volume (1). The flow is fed to the center of the clarification volume in a substantially spiral path (4), wherein the scum (6), which receives the materials to be separated out, forms on the surface. Various apparatuses for performing the method are proposed.

Abstract: A process for separating grease and solid materials from a waste material so as to produce an aqueous discharge liquid. Waste material containing grease, water and solid materials is passed into a screen tank where course solid materials are separated out of the waste material. The filtrate is accumulated and injected into a series of filters wherein each filter is finer than the previous filter. The filtrate is then agitated to produce a foamed liquid which is substantially separated into a foamed oil portion and an aqueous liquid portion. The aqueous liquid portion is separated from the foamed oil portion and discharged into a sewage system. The solids captured during the filtering process are collected and in turn dried to produce a dried material which can be ground and mixed with other products and processed into animal feed, pesticides or the like.

Abstract: Components, usually but not exclusively gaseous components, are removed in a liquid medium from gas streams and chemically converted into an insoluble phase or physically removed. Specifically, hydrogen sulfide may be removed from gas streams by oxidation in aqueous chelated transition metal solution in a modified agitated flotation cell. The same principal may be employed in other procedures in which a gaseous phase is dispersed in a liquid phase to effect an interaction between components present in such phases. A gas-liquid contact apparatus, generally a combined chemical reactor and solid product separation device, comprising such modified agitated flotation cell is also described. In order to effect mass transfer and rapid reaction gas bubbles containing hydrogen sulfide and oxygen are formed by rotating an impeller at a blade tip velocity of at least about 350 in/sec. to achieve the required shear.

Abstract: Components, usually but not exclusively gaseous components, are removed in a liquid medium from gas streams and chemically converted into an insoluble phase or physically removed. Specifically, hydrogen sulfide may be removed from gas streams by oxidation in aqueous chelated transition metal solution in a modified agitated flotation cell. The same principal may be employed in other procedures in which a gaseous phase is dispersed in a liquid phase to effect an interaction between components present in such phases. A gas-liquid contact apparatus, generally a combined chemical reactor and solid product separation device, comprising such modified agitated flotation cell is also described. In order to effect mass transfer and rapid reaction gas bubbles containing hydrogen sulfide and oxygen are formed by rotating an impeller at a blade tip velocity of at least about 350 in/sec. to achieve the required shear.

Abstract: A method and apparatus for aeration of waste water in a dissolved air flotation waste water treatment system includes a container for receiving and retaining waste water for settling of heavy particles and flotation of light particles to the surface of the waste water. Waste water is removed from the container and supplied to a free standing tank. Pressure in the tank is maintained at a predetermined level through the injection of compressed air into the tank. Waste water removed from the tank is pumped through a multiple jet configuration wherein air from the tank is entrained in the waste water as the water is injected back into the tank. The aerated water is discharged from the tank back into the container, thereby providing an efficient aeration process. Aerating the water in a free standing tank separate from the container increases clarification quality as a result of reduced disturbance of the particles floated to the surface of the waste water and reduced need for chemical addition to the waste water.

Abstract: An energy conserving method and apparatus for using induced gas flotation to separate finely dispersed oil and solids from water and doing so in such a manner as to minimize the power consumption, reduce the amount of water carried with the oil and solids skimmings and eliminate complex mechanisms that would require a high degree of maintenance.Initial flotation gas is induced through a high velocity venturi using the inlet flow to supply the kinetic energy. Secondary flotation is supplied by inducing the vapor through a high velocity venturi utilizing recycled water to provide the kinetic energy. A single pump, of relatively low horse power, circulates the recycled water.The oil and solids skimmed from the surface of the water are transferred to an integral compartment for dewatering. The water is returned to the process stream by the single recycle pump.

Abstract: An adsorbent electrode assembly electrically enhances contaminant removal in soil washing processes. The adsorbent electrode assembly is immersed in the froth of a flotation cell and connected to one pole of a battery. The other pole of the battery is connected to the flotation cell tank. The resulting electric charge (either positive or negative depending on the nature of the contaminant) applied to the adsorbent electrode assembly attracts contaminants in the froth to the adsorbent electrode assembly which adsorbs them. The adsorbent electrode assembly is then easily removed from the cell for replacement or regeneration. The adsorbent electrode assembly can comprise one or more carbon rods, a carbon screen, or a porous bag filled with an adsorbent material and having an electrode disposed therein.

Abstract: A method and apparatus for dissolved air floatation (DAF) and for gas-liquid contacting operations by dissolved air floatation. A number of involute flow channels in a container have inlets and outlets positioned at either end for involutional or evolutional flow of a mixture of liquid and dissolved gas. Liquid turbulence and mixing are prevented in order to achieve a near plug-flow condition for maximum separation. Other uses of the method and apparatus include hydraulic flocculation of suspended matters in a liquid, separation of non-floatable suspended matters, oxidation of dissolved organic matter, activated sludge processes, purification of water using a biocide, separation by absorption of gases, stripping by desorption of dissolved gases, and gas-liquid reactions.

Abstract: Liquid process streams--such as white water, pressate, or washer filtrate from a pulp and paper mill--are clarified in an efficient manner using a gas sparged hydrocyclone, which takes up a minimum of floor space. A liquid stream having a consistency of less than about 0.5% solids is introduced into a first end of a vortex. Gas is sparged into the liquid in the vortex to cause particles to attach to gas bubbles and move through a rejects outlet at the first end of the vortex, while clarified liquid is removed from a second end of the vortex. A pedestal is typically provided at the accepts outlet, having a radial clearance with the inside of a porous tube through which the gas is sparged that is about 8-12% the radius of the porous tube.

Abstract: Improved skimmer apparatus for use in dissolved air floatation basins employed in water purification and waste water treatment plants is provided. The invention includes centrally positioned, longitudinal guide rails affixed to the basin and two or more interconnected reciprocating carriages, each carriage having a skimmer blade affixed thereto, the carriages being moveably mounted on the rails. At the effluent end of the basin is an upwardly shaped ramp, and the carriage nearest in proximity to the ramp has a ramp profile duplicating mechanism pivotally mounted to it.

Abstract: Simply stated, in the process of the present invention a hydrocarbon contaminated substrate, such as a hydrocarbon contaminated soil, is separated preferably by wet-sieving, into a coarse fraction and a fines fraction. Thereafter, the coarse fraction is subjected to a floatation process to remove hydrocarbon contaminants from it and the fines fractions is treated with a hydrocarbon solvent followed by an aqueous solution of a surfactant to remove hydrocarbon contaminants from it.

Abstract: A method of removing fine contaminants from waste paper fibrous material (S) is described with solution (1) and pre cleaning (2) whereupon the fibrous material is first subjected to a washing treatment (3) and then to a flotation treatment (5). The washing filtrate (12) from the washing treatment (3) is cleaned in a filtrate-flotation treatment (4) so that a cleaned fraction (14) can be returned into the useful material (13) of the washing treatment. The so cleaned waste paper fibrous material can be passed to further treatment steps such as flotation, bleaching and/or dispersion. The reject material from the filtrate-flotation (4) is, in one embodiment, again subjected to a flotation treatment.

Abstract: Raw feed water is continuously clarified at a large throughput rate in a single, shallow tank using a flotation process carried out simultaneously in multiple sectors of the tank. Raw water feeds into a rotating trough. A fixed manifold system in the trough dispenses pressurized water containing dissolved air to release microscopic air bubbles. A set of headers each radially extend outwardly from the rotating trough. Each header distributes water and bubbles to a sector of the tank with a net zero velocity. A set of rotating extractors each receive clarified water from the bottom of a preceding sector. A set of scoops skim floated sludge from the water in the tank. The sludge is lifted, as by the rotation of the scoop and/or by a pumped conduit, over the rotating trough to a sludge outlet pipe. In one form the scoop has at least two blades each with an eccentrically located, radially extending compartment that receives, lifts, and then dumps the skimmed sludge as the scoop rotates about its axis.

Abstract: A method for clarifying a contaminated fluid in a main separator vessel having therein a cyclonic flow chamber. A spiral preliminary spinner introduces the contaminated fluid to be separated in a stratified condition into the cyclonic flow chamber by a tangential inlet so as to establish a swirling body of fluid; the cyclonic flow chamber has concentric shells positioned below the tangential inlet for discharging separated solids to a collection area and separating an oil and water mixture into a fluid flow zone formed by the cyclonic flow chamber and the wall of the separator vessel wherein water and oil are separated by aeration provided by eductors; a vertical outlet port discharges separated oil and gas from the upper portion of the cyclonic flow chamber to a fluid flow zone wherein oil and gas are separated. The separated water, oil, gas and solids are removed through discharge ports.

Abstract: Hydrogen sulfide or other gaseous component is removed from a gas stream containing the same by distribution of the gas stream in the form of fine bubbles by a rotary impeller and stationary shroud arrangement at a submerged location in an aqueous iron or other transition metal chelate solution, or other suitable catalyst, contained in an enclosed reaction vessel. Sulfur particles, or other insoluble phase product, of narrow particle size range formed in the reaction are floated off from the iron chelate solution. An oxygen-containing gas stream also is distributed in the form of fine bubbles by a separate rotary impeller and stationary shroud arrangement at a separate submerged location in the iron chelate solution. The second submerged location generally is separated from the first by a baffle extending downwardly in the reaction vessel from a top closure towards a bottom closure.

Abstract: Disclosed is a process for recrystallizing materials that are ordinarily difficult-to-comminute. The process utilizes supercritical fluids and gasses at conditions near their respective vapor pressures which have the ability to dissolve in and expand liquid solutions. The process has been shown to be particularly effective at separating HMX and RDX thereby resulting in a precipitate of RDX which is essentially free of HMX.

Abstract: An apparatus for dissolved air floatation (DAF) and for gas-liquid contacting operations by dissolved air floatation. A number of involute flow channels in a container have inlets and outlets positioned at either end for involutional or evolutional flow of a mixture of liquid and dissolved gas. Liquid turbulence and mixing are prevented in order to achieve a near plug-flow condition for maximum separation. Other uses of the method and apparatus include hydraulic flocculation of suspended matters in a liquid, separation of non-floatable suspended matters, oxidation of dissolved organic matter, activated sludge processes, purification of water using a biocide, separation by absorption of gases, stripping by desorption of dissolved gases, and gas-liquid reactions.

Abstract: A system for cleaning water in rivers or lakes or for separating oil and water. The system includes a sucking pipe; vapor-liquid mixing device connecting to the sucking pipe; a pressure pump disposed midway of the sucking pipe; a compressor connected to the connection between the pressure pump and the vapor-liquid mixing device; a pressure tank connected to the vapor-liquid mixing device; a feed pipe connected to the pressure tank; and a pressure valve, attached to the leading end of the feed pipe, which opens at a pressure exceeding a predetermined level. According to this system, the construction can be simplified, and the lifting action by the bubbles can be effected by keeping the pressure of the liquid at a predetermined level or more at all times. Thus, the system can be used anywhere under all circumstances.

Abstract: A method of separating desired material from undesired material is provided. The method is performed by forming a slurry of material and introducing it into a specially designed flotation reactor chamber. A foam is generated and introduced into the reactor chamber and dispersed into the slurry. A stream of water is provided to separate the undesired portion of the material from the desired portion of the material that has adhered to the bubbles in the foam.

Abstract: A method for the beneficiation of mineral ores by the flotation method whereby a slurry is introduced under pressure into the top of a first column through a downwardly facing nozzle, and air is entrained into the slurry forming a downwardly moving foam bed in the first column. The foam bed passes from the bottom of the first column into a second column where the froth and liquid separate, the froth carrying the values floating upwardly and over a weir and the liquid being drained with the gangue. The liquid/froth interface level in the second column is kept above the bottom of the first column, and the air flow rate into the top of the first column is controlled to keep the first column substantially full of foam.

Abstract: The invention is directed to a method of regulating a flotation system having an inflow quantity of suspension flow dependent on production demands, including a primary flotation stage and a secondary flotation stage where the secondary flotation stage treats the froth of the primary stage, transporting de-aereated froth from the primary flotation stage to a collection vessel which is in fluid communication the secondary flotation stage; recycling suspension flow from the secondary flotation cells of the secondary flotation stage in part to an inlet of the primary flotation stage, and in part to an inlet of the secondary flotation stage, and regulating the level of de-aereated froth in the collection vessel by controlling the amount of suspension flow recycled from said secondary flotation stage to the inlet of the secondary flotation stage.

Abstract: A system and method for removing asbestos and other hazardous solids from a slurry collected during removal of insulation from pipelines, equipment and other structures. The slurry is collected in a collection pan that is attached to a shroud of a hydrocleaning machine. Solid particles are separated from the slurry by passing the slurry through various stages of filters. Pumps are used to transfer the slurry from the collection pan through the filter stages. A first flocculent is injected into the slurry to coagulate the solid particles into individual masses. A second flocculent is injected into the slurry, downstream from the injection point of the first flocculent, in order to coagulate a majority of the remaining solid particles. The coagulated masses of solid particles are removed by passing the slurry through a screen shaker. The slurry discharged from the screen shaker is then passed through further filters.

Abstract: An apparatus and method for de-inking waste paper pulp using a foam flotation process to recycle printed waste paper for the manufacture of new paper. Pulped printed paper is fed as a slurry to an inlet of a shallow tank. Internal guide walls in the tank establish a flow path from the inlet to an outlet. The walls are sized and positioned to create a generally uniform cross-sectional flow area. A plurality of modules are disposed along the flow path. Each module includes at least one injector that aerates the flow and an extractor that removes floated ink foam. A portion of the flow from each module is recycled to an upstream module, preferably by a conduit and associated pump. In a preferred form, an injector (or injectors) alone located at the inlet is fed by the next downstream module and an extractor alone is located near the outlet. The invention also includes a main recycling loop from the downstream end of the flow path to the upstream end.

Abstract: A process for gas entrainment of wastewater in an anaerobic wastewater treatment system includes the steps of withdrawing wastewater from an anaerobic digester and piping it into a flotation container. Thereafter the wastewater is pumped into a free standing tank having pressure in the tank maintained at a predetermined level through the injection into the tank of compressed gas generated by anaerobic digestion occurring in the treatment system. The wastewater is removed from the tank and pumped through a multiple jet configuration wherein gas from the tank is entrained in the wastewater as the water is injected back into the tank. The gas entrained water is then discharged from the tank back into the flotation container where the gas bubbles particles to the surface of the water to form a sludge layer.

Abstract: An apparatus and a method are disclosed for separating a first fluid from a second fluid wherein the first fluid is lighter than the second fluid and the first fluid is immiscible with the second fluid. A first portion of the first fluid is separated from a mixture containing the first and second fluids in a gravity separator. The remaining mixture flows to a hydrocyclone where a second portion of the first fluid is separated from the remaining mixture. The underflow from the hydrocyclone which includes most of the second fluid and the remaining portion of the first fluid flows to a second gravity separator without substantial pressure reduction to avoid shearing of the droplets of the first fluid. In the second gravity separator a third portion of the first fluid is removed.

Abstract: A high rate multi-stage bubble separation process is developed for: (a) initially generating coarse gas bubbles with diameters greater than 80 microns in turbulent hydraulic condition to mix an influent water with chemicals, enzymes, microorganisms, or combinations thereof, to produce chemical flocs, biological flocs or both, and to strip volatile contaminants from water; (b) subsequently terminating coarse gas bubbles and generating extremely fine gas bubbles with diameters smaller than 80 microns in laminar hydraulic condition to float suspended, oily and surface-active contaminants together with said chemical flocs and said biological flocs from water, to settle heavy contaminants from water, and to produce a clarified effluent water, a floating scum, and a sludge; (c) terminating the fine gas bubbles and discharging the clarified effluent water; (d) discharging the floating scum and the sludge upon demand; and (e) optionally collecting and treating an emitted gas stream resulting from said coarse gas bubb

Abstract: A method and several embodiments of apparatus are disclosed for use in foam flotation separation. The method discloses performing the separation in a module operated at nonatmospheric pressure, and the apparatus disclosed are suitable for use as the module of the method. Both the method and the apparatus contemplate positive and negative pressure operation.

Abstract: A process is disclosed for the removal of hydrocarbons such as bitumen or heavy fuel oil from hydrocarbon contaminated sludge, or particulate solid material or the like non-homogenous material after appropriate conditioning, such as by ball milling, with the conditioned material being aerated and then fed substantially tangentially into a substantially vertical cyclonic separator vessel to cause the hydrocarbons to which air bubbles have become attached to tend to float as a froth to the top of the vessel, with the remaining solids sinking to the bottom of the vessel. The hydrocarbon containing froth is then removed from the top of the vessel, and the remaining solids removed from the bottom of the vessel. This pneumatic flotation process obviates the need to add chemicals such as wetting agents or promoters.

Abstract: A wastewater flotation separation system is provided, which operates effectively with a minimum of maintenance. The apparatus includes a container (12) for holding wastewater, an inlet (14) located at a lower portion of the container, and an aerator (24) adjacent to the inlet for generating air bubbles that cling to waste particles to bring them to the water surface. A skimming apparatus (30) which skims particles off the surface of the wastewater into a sludge receiver (44) includes a beach device (42) with an inclined upper surface (40), and a belt device (34) that moves a series of scrapers (32) along the surface of the water and along the beach device into the sludge discharge. Each scraper includes a flap of resilient material which is bent as it scrapes along the inclined beach surface.

Abstract: A method of separating an aqueous solids containing suspension includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a).

Abstract: Phase separation equipment for thermally separating an emulsion, in particular, a water-oil emulsion, includes a container for receiving the emulsion, a heater for heating the emulsion in the container, a discharge outlet from the top of the container for evacuating a vapor phase of the emulsion and a system for introducing air into the lower region of the container for forming a vapor cloud at the surface of the emulsion at a lower temperature than would be expected. The vapor cloud is discharged from the container, and the condensible portion of the vapor is condensed and separated from the vapor stream. The separated air or residual gas is then fed back into the air stream supplied to the bottom area of the container so that a closed loop air circulation system is provided. The system avoids discharge of air and noxious odors into the atmosphere while enhancing the separation of the lower boiling point vapor from the emulsion.