Abstract: The invention relates to the treatment of waste water containing a harmful ion such as a heavy metal ion or fluorine ion by the coagulating sedimentation method using an inorganic coagulant such as an iron compound or an aluminum compound. After separating treated water from the sediment (sludge) in which the harmful ion is incorporated in insoluble form, the pH of a mixture of the sediment and water is suitably adjusted to cause elution of the harmful ion from the sediment. Then the sediment is separated from the eluate and reused as an inorganic coagulant. By reusing the sediment in this manner, the waste water treatment is accomplished without producing a large quantity of sludge and the consumption of inorganic coagulant and auxiliary chemicals can be greatly reduced, while the concentration of the harmful ion in the treated water becomes sufficiently low.

Abstract: A method for the treatment of sludge obtained from such a water treatment process wherein an aluminium or iron chemical is used as a coagulant, so as to reduce the amount of sludge, which method comprises the steps of:a) treating the water treatment sludge with an inorganic acid to produce an acidic sludge comprising dissolved aluminium or iron,b) optionally separating insoluble material from the acidic sludge to produce an acidic solution comprising dissolved aluminium or iron,c) treating said acidic sludge or said acidic solution with a +1-cation compound in the presence of sulphate ions in such conditions that the pH of the sludge or solution remains at a level where aluminium precipitates as an alunite compound or iron precipitates as a jarosite compound, andd) separating the precipitated alunite or jarosite compound from the remaining sludge.

Abstract: Impurity streams generated during the metallurgy of copper are hydrometallurgically processed at ambient pressure for recovery of primary values in an energy-efficient manner and with the capture and conversion of metallic impurities to states that are acceptable for disposal into the environment. Hallmark features of the various embodiments of this invention include the water leach of flue dust, a controlled acid leach stage in which metal species are solubilized, the extraction of copper as a sulfide, and the ability to operate the various process stages at essentially ambient pressure.

Abstract: Fine particles are dewatered in an energy efficient process in which a non-polar liquid or a mixture of different hydrophobic liquids are used to displace the water from the particle surface. Thermodynamically, this process is spontaneous. The only energy required for this process is to recover the hydrophobic liquid(s) for recycling purposes. The hydrophobic liquids are recovered in gaseous form either by lowering the pressure or by heating, and converted back to liquid form for re-use. The most economical reagents that can be used for this purpose include propane, butane, pentane, and ethane. Carbon dioxide may also be used for the dewatering process described in the present invention. The process of dewatering by displacement is capable of achieving the same or better level of moisture reduction as thermal drying but at substantially lower energy costs.

Abstract: A borated aqueous solution from a nuclear reactor coolant system dilute chemical-decontamination process or from an equipment washing process which has been contaminated with radioactive metals or heavy metals including cobalt, nickel, chromium, iron, manganese, lead or mercury and with a chelating agent, detergent or soap is treated with an oxidizing agent to oxidize the chelating agent, detergent or soap and to precipitate the contaminant metals. The contaminant metals are then separated from the solution by centrifugal filtration, micromembrane belt filtration or magnetic separation. Advantageously, a very small volume of precipitate may then be buried and the decontaminated solution may be recycled or further treated and released for other uses.

Abstract: Metals and organics are extracted from solution by co-precipitating them with a gel comprising aluminum hydroxide and a complexing agent such as EDTA. After the gel is processed to remove the metals and organics, it can be recycled for further use by dissolving it in a high-pH solution, leaving no secondary waste stream. A number of alternative complexing agents perform better than EDTA.

Abstract: A process to purify waste waters using chemical oxidation and Fenton's reagent by the action in the acid range of hydrogen peroxide and iron(II) compounds and subsequent precipitation in the weakly acid to alkaline range of the iron(III) compounds, said process being characterized in that the sludge containing iron(III) accumulating in addition to the purified waste water is reduced electrolytically back into iron(II) compounds and in that the sludge so reduced is fed back into the process. The process of the invention allows extensive purification of highly concentrated waste waters and furthermore problems arising with the treatment and elimination of the Fenton sludge can be circumvented.

Abstract: Fine coals are dewatered in an energy efficient process in which a non-polar liquid or a mixture of different hydrophobic liquids are used to displace the water from the coal surface. This process works with higher rank coals that are naturally hydrophobic so that the coal surface from which the water is displaced has a stronger affinity for the hydrophobic liquid than the water. Thermodynamically, this process is spontaneous and, hence, requires no energy. The only energy required for this process is to recover the spent hydrophobic liquid(s) for recycling purposes. The hydrophobic liquids are recovered in gaseous form either by lowering the pressure or by heating, and coverted back to liquid form for re-use. The most economical reagents that can be used for this purpose include propane, butane, pentane, and ethane. Carbon dioxide can also be used for the dewatering process described in the present invention.

Abstract: A process and apparatus for batch treatment of a liquor to separate, by way of example, a suspension of a contaminant from a liquor is disclosed. The batch treatment apparatus comprises, a single batch vessel that has discharge outlets at an upper and a lower level of the vessel, and an agitator that is operable in accordance with the batch treatment process to mix the contents of the vessel. The batch treatment process comprises, forming floccs of the contaminants and a carrier which settle rapidly towards the base of the vessel, discharching the relatively contaminant free liquor through the upper discharge outlet, breaking bonds of the floccs so that the carrier separates from a sludge of the contaminant and flocculent residue, discharging the sludge through the lower discharge outlet, and re-using the carrier in the treatment of a new batch of liquor.

Abstract: A process for removing silica in dissolved or colloidal form from an aqueous liquor comprising, precipitating/adsorbing the silica with or onto a precipitant/adsorbent, typically a compound containing aluminium, magnesium, or iron, forming floccs of the precipitated/adsorbed silica, and separating the floccs from the liquor.

Abstract: Impurity streams generated during the pyrometallurgy of copper are hydrometallurgically processed at ambient pressure for recovery of primary values in an energy-efficient manner and with the capture and conversion of metallic impurities to states that are acceptable for disposal into the environment. Hallmark features of the various embodiments of this invention include the water leach of flue dust, the extraction of water-soluble copper as a separate product, a controlled acid leach stage in which bismuth is solubilized, the return of copper to the smelting process as a sulfide, the ability to operate the various process stages at essentially ambient pressure, and the gradual reduction in temperature over the course of the process without the use of indirect heating or cooling operations.

Abstract: A method of immobilizing a contaminant comprising mixing the contaminant with a reaction partner that is capable of chemically interacting with the contaminant to form a water-insoluble reaction product, the reaction partner being mixed in the form of a hydrophobic solid preparation, which is either obtained by grinding the reaction partner with an inert material and treating it with a hydrophobing agent or which contains the educt or reaction product of a dispersion by chemical reaction preliminarily treated with a hydrophobing agent, the mixing being conducted to form a soil or soil-like material with cohesive constituents of a clay-like structure.

Abstract: Metal cations absorbed within a hydrogel chelation polymer are insolubilized for safe disposal by treating the polymer with a precipitative anion such as carbonate, aluminate, hydroxide, phosphate, silicate, or sulfide. Further insolubilization of the metal cations may be achieved by subsequent treatment of the polymer with a water-dilutable prepolymer composition such as phenol-formaldehyde resin, then heating to cause cross-linking of the prepolymer. The hydrogel chelation polymer, containing metal sulfide formed by virtue of the insolubilization process, is useful in abstracting from water metals whose sulfides are less soluble than the metal sulfide initially within the polymer.

Abstract: A cyclic photocatalytic process for treating waste water containing metal and organic contaminants. In one embodiment of the method, metal ions are photoreduced onto the photocatalyst and the metal concentrated by resolubilization in a smaller volume. In another embodiment of the method, contaminant organics are first oxidized, then metal ions removed by photoreductive deposition. The present invention allows the photocatalyst to be recycled until nearly complete removal of metal ions and organic contaminants is achieved.

Abstract: A method and apparatus for treating a surface of an aluminum substrate for a printing plate includes treating the substrate surface with a treatment liquid being circulated, separating and discharging aluminum ions from a portion of the treatment liquid, recovering a sodium hydroxide solution from the treatment liquid, mixing the recovered sodium hydroxide solution with the treatment liquid being circulated, and maintaining a predetermined concentration of aluminum ions in the treatment liquid to be used. A portion of the treatment liquid containing sodium aluminate solution is mixed with aluminum slag containing an amorphous aluminum hydroxide produced at the time of neutralization of a waste acid and a waste alkali produced during surface treatment to thereby supersaturate the sodium aluminate solution, crystallize the aluminum hydroxide, and recover the sodium hydroxide solution to be returned to a liquid control tank to maintain a predetermined concentration of aluminum ions in the treatment liquid.

Abstract: Compositions useful as absorbents for organic liquids are disclosed. A diamine or polyamine is reacted with a polymeric resin that contains phosphonic acid groups to produce the absorbent compositions of the invention. Because the polymeric resin component can be combined with the amine either before or after combination with the organic liquid, the absorbents of the invention can be used in many forms. The polymeric resin component can be processed into any desired form (shaped article, solution), and the di- or polyamine can then be added to generate the absorbent in situ. Unlike spent absorbent compositions of the prior art, those of the invention can be converted to pumpable liquids by heating or by adding a gel-breaking agent to liquify the gel. A useful absorbent is recovered from the liquid by precipitation or distillation.

Abstract: A method is provided for treating "spills" of materials, e.g. an offshore oil spill, wherein an ungelled mixture of gelatin is deposited onto the material and then allowed to gel. As the gelatin gels, it "traps" or entrains the material into the gelled mass of gelatin whereby the material can readily be retrieved by merely retrieving the gelled gelatin. The gelling of gelatin is fully reversible in that gelatin will return to its liquid state merely upon reheating, thereby allowing the spilled material to be separated from the gelatin so that the material can be recovered and the gelatin to be reused.

Abstract: A process for treating contaminated sludges such as municipal sewage sludge, industrial waste sludge and riverbottom sludge with calcium oxide (CaO) and/or calcium carbide (CaC.sub.2) with reclaiming and recycling of calcium oxide (CaO) from the reaction materials. The process is also applicable for dechlorinating PCB contaminated sludges.

Abstract: A method of immobilizing a contaminant comprising mixing the contaminant with a reaction partner that is capable of chemically interacting with the contaminant to form a water-insoluble reaction product, the reaction partner being mixed in the form of a hydrophobic solid preparation, which is either obtained by grinding the reaction partner with an inert material and treating it with a hydrophobing agent or which contains the educt or reaction product of a dispersion by chemical reaction preliminarily treated with a hydrophobing agent, the mixing being conducted to form a soil or soil-like material with cohesive constituents of a clay-like structure.

Abstract: In a method of dewatering suspensions or the like slurry-like mixtures, in particular waste water slurries, fed to a belt filter press formed by filter belts, with the waste water slurry, is a crumbly dry substance which has been produced by drying from the solids discharge of the belt filter press.

Abstract: Process for softening hard water by precipitation of calcium carbonate. The hard water is rendered alkaline, e.g. by the addition of sodium hydroxide, and is then contacted with a large excess of calcium carbonate crystals whose size does not exceed 100 microns, whereby precipitation occurs within a short contact time of the order of 2-60 seconds. Upon separation of soft water from calcium carbonate the bulk of the latter is recirculated and excessive amounts are removed.

Abstract: Sewage sludge is subjected to a treatment with an acid in order to form stable ammonium compounds before thermal drying of the sludge which would otherwise volatilize ammonia and diminish the nitrogen content of the sludge.

Abstract: The invention concerns a process for lowering or eliminating the sodium and potassium ion content in various forms of waste. According to the process, waste is treated with the residue, itself regarded as a pollutant since rich in fluosilicic acid, discharged from the manufacture of sulfuric acid on a calcic ore based on calcium phosphate.

Abstract: A method is provided for selectively treating flocculated heavy metal contaminated iron-based sludges from an industrial waste water treatment process. The method removes the heavy metal contaminants with a minimum loss of the iron therein. The method comprises dissolving the sludge in hydrochloric acid to produce a ferric chloride solution. The solution is filtered to remove precipitated heavy metal salts, such as lead chloride. The filtrate containing the remaining heavy metal chlorides and ferric chloride is then cooled or otherwise treated to remove additional heavy metal chlorides. The remaining ferric chloride based solution is then reduced (exposed to iron powder) to a ferrous chloride solution and heavy metals. After filtration of any additional precipitated heavy metals, the ferrous chloride solution is ready for recycling.

Abstract: Wastewater containing impurities refractory to secondary treatment is first introducted into an aerobic biological treatment stage operating with an oxygen-enriched stream and subsequently into a precipitation stage where the biologically treated wastewater is combined with Ca(OH).sub.2 to precipitate Ca(OH).sub.2 CaCO.sub.3 sludge which adsorbs or occludes impurities. The clear liquid, separated from the resultant sludge, is passed to a second precipitation stage where it reacts with a CO.sub.2 and oxygen-containing waste gas at least in part from the aerobic biological treatment stage, thereby forming additional CaCO.sub.3. Waste gas withdrawn from the second precipitation stage, being enriched in oxygen is recycled to the aerobic biological treatment stage.

Abstract: This invention relates to the removal of hypochlorite groups from aqueous effluent solutions, so as to permit the disposal of the effluent by deep well injection. More particularly this invention relates to the catalytic decomposition of such hypochlorite groups from scrubbing water effluent used to remove chlorine from a gaseous effluent, wherein a solid catalyst is dissolved, recycled and reprecipitated in situ.

Abstract: An improved process for removing dissolved metals from waste water using a recycle high density sludge is described. Specifically, the process comprises the steps of: (1) treating waste water containing dissolved metals with a recycle stream containing alkaline surface active recycle particles to precipitate the dissolved metals on the surface of the recycle particles; (2) treating a portion of the treated waste water containing metal precipitate solids with an alkaline reagent to form alkaline surface active recycle particles; (3) recycling the alkaline treated stream containing the alkaline surface active particles; and (4) separating the portion of the stream from step (1) not treated with alkaline reagent into a water component which is free of dissolved metals and solids and a sludge component which contains solids.

Abstract: The invention provides a chemical process for the treatment of water containing dissolved calcium and sulphate ions, so as to produce a purified product water having a reduced sulphate ion concentration. Barium sulphide is added to the water to cause precipitation of barium sulphate from the water. The water from which the barium sulphate has been precipitated is then treated with carbon dioxide to form hydrogen sulphide in the water, and the hydrogen sulphide is stripped from the water.

Abstract: A useful method for the recovery of heavy metal sulfides and alkali or alkaline earth metal salts of N-substituted dithiocarbamic acids from material containing heavy metal salts of N-substituted dithiocarbamic acids.

Abstract: Method of treating liquid by sedimentation in which reagents are injected into a flow of untreated liquid and there is created in the flow a colloid mixing and stabilization area; the flow is passed into an intermediate aggregation area and then into a sedimentation area equipped with separator plates from which clarified liquid is taken; characterized in that insoluble granular material which is more dense than the liquid is injected into the liquid in predetermined proportions in the mixing area where the flow is made turbulent, turbulence is induced in the intermediate aggregation area to maintain the granular material in suspension, virtually all of the granular material is brought into the sedimentation area, the sludge recovered in the sedimentation area is removed, the granular material is removed therefrom (D) and is recycled after cleaning.

Abstract: Hydroxylammonium salts are eliminated from wastewaters containing such salts by a process which comprises treating a wastewater containing such salts with not less than 0.5 mole of manganese (IV) oxides per mole of hydroxylamine in the form of hydroxylammonium salts at a pH of from 1 to 4 and at from 10.degree. to 100.degree. C.

Abstract: A method for removing suspended impurities and colored substances from water which is hard and/or has a pH in excess of 5 which comprises contacting the water at its natural pH with a coagulant/adsorbent which comprises a finely divided particulate mineral material, the individual particles of which have a thin hydroxylated surface layer having a positive zeta potential at the adsorption pH, and separating the thus treated water from the coagulant/adsorbent.

Abstract: A method is provided for recovering gold and silver from precious metal bearing materials including ores, leaching residues, flue dust, electronic scrap, jewelry scrap, etc. In the method, the gold and silver are extracted from the precious metal bearing materials with a thiourea solution to form a thiourea leach, and the thiourea leach is contacted with carbon to adsorb the gold and silver and provide loaded carbon. The method is characterized by the step of contacting an alkaline solution of thiousulfate ion with the loaded carbon thereby desorbing the precious metals form the carbon. In one modification of the method, an additional step includes adding a salt to the aqueous thiousulfate solution. When needed, the method includes the step of protecting the thiousulfate ion from oxidizing agents. This is done by adding a reducing agent such as sodium sulfite to the thiousulfate solution.

Abstract: A method of treating organic waste is provided which includes separating the liquid portion of the waste from the solid portion prior to reacting said solid portion in an accelerated wet oxidation reaction. The method includes using an internally-derived ash from the wet oxidation reaction to weight the organic waste, thereby increasing the rate at which the liquid phase can be separated from the solid phase. By first removing the liquid portion of the waste, the oxygen demand of the waste to be processed by wet oxidation is substantially lowered. Ammonia is removed from the liquid portion of the waste in a de-ammoniating step which is followed by biological decomposition to form a liquid stream having a greatly reduced oxygen demand. In one embodiment, the method includes further treating the liquid stream to substantially remove salts and using the resulting deionized stream as a diluent to dilute the solid portion of the waste prior to wet oxidation.

Abstract: A system and method for converting pulp and paper mill waste water into a decolored, neutral pH effluent and a solid suitable for use as fuel in a furnace. The treatment system is used following primary and secondary treatment of pulp and paper mill waste waters typically found in the industry. After secondary biological treatment, the waste waters are pumped to a coagulation tank where the waste water is brought in contact with a polyamine coagulant which coagulates lignins, degraded sugars, and other compounds which typically discolor this water. The coagulation particles are increased in size by addition of an acrylamide polymer in a flocculation tank to improve the hydrophilic characteristics of the coagulant. The waste water is then mixed a dissolved air and water solution under pressure. Upon dissolution of the dissolved air at atmospheric pressure the air is absorbed by the flocculated matter in the aeration tank and the flocculated matter is caused to migrate towards the area of less pressure, i.e.

Abstract: A process for the decolorization of alkaline pulp such as that derived from paper waste water wherein the waste water is contacted with a strong mineral acid, contacted with a coagulated agent and then the solid coagulum is separated and neutralized to liquify the color bodies in concentrated form.

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.

Abstract: In the process for the purification of water by flocculation, a porous granular material is used as a decantation accelerator and is preferably constituted by pyroclasts which can act as a substrate for a bacterial growth which achieves biological purification together with the chemico-physical purification of the flocculation.

Abstract: The invention relates to a process for obtaining purified water from wet sludges and slurries of solid materials by treating these materials with a clathrate forming agent at a temperature above the freezing point of water to form a solid clathrate and dewatered solid material. The clathrate and solid material are then separated and the clathrate decomposed to give purified water and clathrate forming agent.

Abstract: The invention relates to a method for purifying aqueous solutions containing at least one impurity element from the group consisting of arsenic, phosphorus, mercury and other heavy metals and solid matter by precipitation in at least two stages with the aid of precipitation reagents possessing ions capable of forming not-readily dissolved hydroxide precipitate. In accordance with the invention the main part of the precipitation reagent is introduced to the stage or stages following the first stage. The impurity element-containing precipitate formed in the aqueous solution subsequent to adding the reagent is separated therefrom substantially completely, and is returned so as to be present in the first precipitation stage, while that part of the solution which has been freed from precipitate in a later stage is withdrawn from the system. Substantially all the impurity element amount present in the ingoing aqueous solution are separated therefrom in the form of a sludge prior to the second precipitation stage.

Abstract: An electrical machining system utilizing a machining liquid consisting at least in a major part of an aqueous solution containing a deionized water and a surface active agent dissolved therein, the latter having a temperature-dependent solubility in the solution and a cloud point, i.e. a temperature below which it remains dissolved therein. The machining liquid is supplied into a machining zone which produces a liquid effluent in which machining products are entrapped. The liquid effluent is fed to a separation zone where it is heated at a temperature above its cloud point to separate out an amount of the surface active agent and to collect that amount substantially in a solid form while forming a liquid output constituted by a remainder of the liquid effluent. The surface active agent is collected by deposition on a carrier material, e.g. iron particles. When iron particles are used, an electromagnet may be employed to decrease the time necessary to recover the surface active agent.

Abstract: Waste-containing (contaminated) waters are treated for reuse and disposal with acceptable environmental improvements by adding a sulfate salt of aluminum and/or iron alkalized to form a waste-cohering hydroxide floc in one or more treatment plants, recovering the flocs and wastes by contacting with sulfur oxides to redissolve the aluminum and/or iron for reuse, in which case low cost sulfur containing fuels are utilized to provide heat and sulfur for recovering over one-half of the sulfur dioxide for reuse and reducing the lime required to neutralize the acidity.

Abstract: The instant invention relates to a process for the extraction of oil from an aqueous phase with the use of a sulfonated polymer as an extracting agent.

Abstract: A process for the selective recovery of cadmium, molybdenum, zinc, nickel and other metal values from wet process phosphoric acid and other acidic to slightly basic carrier solutions, wherein the metal-bearing solution is contacted with an organophosphene extractant to precipitate the metal values for subsequent separation from the solution. Separation may be effected by mechanical means or by scrubbing with a water-immiscible organic solvent such as kerosene for subsequent recovery of the metal values. The metal specie recovered is determined by the concentration of the organophosphene, which may be selectively adjusted to recover a series of metal values in a sequence of stages.

Abstract: The instant invention relates to a process for the extraction of oil from an aqueous phase with the use of a sulfonated polymer as an extracting agent.

Abstract: To reduce the amount of high quality energy utilized in removing water from a dilute ethanol solution, a two-stage process is used. The first stage removes eighty-five percent of the water using a low temperature apparatus and process and the remainder of the energy is removed by any of the other conventional processes. In the first stage, anhydrous sodium sulfate is dissolved in a dilute aqueous solution of 10 weight percent alcohol at approximately thirty degrees centrigrade. The solution is cooled to approximately twenty degrees centrigrade, at which temperature decahydrate crystals of sodium sulfate precipitate from the solution are removed. The solution is increased to a value in excess of 45% of alcohol which requires removal of approximately 82 percent of the water in the form of crystals. The crystals are dried to the anhydrous state at substantially room temperature and reused.

Abstract: The invention relates to a process for removing carbon black from an aqueous suspension obtained by washing a gas containing carbon black with water. To this end, a gas stream comprising hydrocarbons and at least one inert gas is introduced into a suspension having a solids content of from 0.5 to 4% by weight, at a temperature of from 10.degree. to 80.degree. C. In so doing, the carbon black agglomerates and collects on the surface of the suspension water from which it is separated, for example by skimming it off. The gas stream is produced by passing inert gas over the separated carbon black containing the hydrocarbons and heated to 200.degree. to 400.degree. C., the carbon black being converted into a dry, free-flowing material.

Abstract: To extract a metal value, particularly aluminium, from an aqueous feed stream containing the value to be extracted is treated in a recovery unit from which it passes to a contactor where it is contacted with a solvent stream including a partially water soluble extractant for the value and an organic diluent. The delivery from the contactor is separated into an organic phase, an aqueous raffinate and a dispersed intermediate phase. The organic phase is stripped of the value and recycled to the solvent stream. The raffinate as recycled by being added to the feed stream, and the intermediate phase is treated for recovery of extractant.

Abstract: An improved process for recovering and recycling coagulant present in water treatment sludges. The improvement comprises several steps. First, enough acid is added to the sludge to solubilize most, but not all, of the coagulant in the sludge. Next, the acid-treated sludge is filtered on a non-mechanical horizontal filter to produce the recovered coagulant in solution as the filtrate. The recovered coagulant has a greater coagulative effect, when later recycled to treat raw water, than the mole equivalent of commercial coagulant. A portion of the recovered coagulant is discarded to control the increase in concentration of unwanted impurities in the recovered coagulant. Finally, this process permits neutralization and later removal of the filtered sludge on the surface of the non-mechanical horizontal filter.

Abstract: Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.