Abstract: The method of the invention is advantageously applicable to realize a multistage chemical process during which liquid clarifiers suitable for the purification of water and sewage, furthermore, fine-disperse pulverulent solid products utilizable as pait pigments and fillers may be recovered. Each final product of the multistage chemical processes is a useful material, so the whole technology is waste free.

Abstract: The process for immobilizing a hazardous waste containing heavy metals comprises the steps of pretreating the waste by adding a sulfide to the hazardous waste so as to generate the sulfides of the heavy metals from the hazardous waste, mixing a chemical reagent with the pretreated waste, and blending the mixture of the chemical reagent and the pretreated waste with a pozzolanic material. The chemical reagent contains a mixture of a retarder and an accelerator. This process further comprises the step of mixing a neutralizing reagent with the hazardous waste so as to cause the hazardous waste to have a pH of between 5 and 14. The neutralizing reagent is an alkaline material, preferably lime, hydrated lime, or calcium hydroxide. The sulfide is either sodium hydrosulfide or sodium sulfide.

Abstract: A method for reducing the residual amine content of dried solids by adding water to the dried solids to form a wetted solids mixture and drying the wetted solids mixture to yield a dried product with a final amine content less than the residual amine content of the dried solids. An alkaline composition is also disclosed which further reduces the final amine content of the dried product.

Abstract: Fats and proteins in wastewater are commonly concentrated in a dissolved air flotation cell as a sludge ("skimmings") which has a very high water content, even after centrifuging or the like. A process is provided to reduce the water content of the sludge thereby reducing the cost of disposal of the sludge.

Abstract: A method and apparatus for recovering oil from an oil spill on the surface of a body of water. The method is operative for recovering an oil having a viscosity in excess of 80 centipoise and it includes the steps of drawing an oil-water mixture from the surface of a body of water, adjusting the viscosity of the oil in the oil-water mixture to a level below approximately 80 centipoise and passing the resultant adjusted oil-water mixture through an oil-water coalescer to separate the oil in the adjusted oil-water mixture from the water therein. The viscosity of the oil in the feed oil-water mixture is preferably adjusted by adding a low viscosity hydrophobic hydrocarbon solvent to the oil-water mixture.

Abstract: A process for the heavy-metal decontamination of contaminated substances such as natural and industrial sludges, thermal residues and soils. The contaminated starting substance is treated with an acid and the dissolved metal salts are precipitated as metal hydroxides in the pH range of about 3.5-11. The exact control of the pH value makes it possible to isolate individual metal fractions which can be used as raw materials in the metallurgical industry.

Abstract: Waste liquors containing small amounts of silver salts are treated with aluminum hydroxide to produce a floc reduced in volume by the addition of an acid and mixed with a metal bicarbonate and metal carbonate in amounts sufficient to affect solidification.

Abstract: A method of paint sludge conversion and sludge removal from a sump pit for disposal is provided which is particularly adapted for use with paint waste sludge derived from wet spray booth operations. The method involves blending with the starting sludge caustic, oil and emulsifiers. Water may be added to achieve a desired water to total solids weight ratio. The product is a pumpable liquid disperse system which is easily charged to tankers or the like for pump out from the sludge pit.

Abstract: The present invention relates to a high rate method for combining waste materials to produce valuable products for agricultural, horticultural, sylvicultural or public use. Specifically, the present invention combines the steps of alkaline stabilization, beneficiating and pelletizing waste materials, such as wastewater treatment plant sludge or animal excrement and reaction with carbon dioxide, to thereby convert the waste materials to useful products such as soil conditioners or fertilizer supplements.

Abstract: Finely divided aqueous mineral slurries such as kaolin clay and calcium carbonate are dewatered, filtered and prepared for shipment by and with the addition of an effective amount (preferably 0.01 to 4.0 pounds per ton of solids) of melamine/formaldehyde polymer.

Abstract: Aqueous mineral slurries are treated prior to dewatering, to increase throughput, with a condensation product of formaldehyde and dicyandiamide, which may be further reacted with ammonia or an ammonia salt and an alkylenepolyamine or copper chloride.

Abstract: A process of selectively recovering a nitrophenolic by-product, namely 2,4-dinitrophenol and picric acid, from nitration waste water in substantially pure form through the control of the solution pH of the nitration waste water and subsequent precipitation is provided. By adjusting the solution pH of the nitration waste water with an acid to a pH in the range of from about 4.0 to 0.5, the solubility of the selected nitrophenolic by-products is affected and the crystal formation of the individual by-products controlled.

Abstract: A process for treating wastewater containing insoluble solid waste material and soluble solid waste material including the following series of steps: (1) controlling the oxygen content of the wastewater to a level at which growth of anaerobic bacteria is substantially eliminated, (2) separating the insoluble solid waste material from the wastewater, (3) treating the soluble solid material in the wastewater with a predetermined amount of aerobic bacteria, and (4) reducing the amount of aerobic bacteria in the wastewater. The insoluble solid waste material separated from the wastewater can be burned to produce electrical energy. Apparatus for carrying out the process are also disclosed.

Abstract: A method of removing a constituent of a biological fluid including a blood component, said method including flowing the biological fluid past one side of a first semipermeable membrane; flowing solution containing a first precipitation agent past a second side of the membrane so as to cause transfer of the precipitation agent through the membrane to the biological fluid so as to improve precipitation characteristics of the fluid; and precipitating the constituent from the biological fluid. Also disclosed are maintaining a lower pressure in a biological fluid in a dialyzer than in dialysate at all portions of a membrane in the dialyzer and adding a continuously flowing stream of concentrated precipitation agent to a continuously flowing stream of a biological fluid.

Abstract: A method of processing an aqueous feed liquid to precipitate at least one metal (e.g., copper, nickel or a combination thereof) in a form to make the metal subsequently removable from the feed liquid by filtration, comprises the initial step of mixing (i) an aqueous feed liquid containing a soluble salt of the metal to be removed, (ii) oxalic acid in excess of that required to react with metal, and (iii) a pH-adjusting liquid in a quantity sufficient to lower the pH of the feed liquid to a point between that at which the feed liquid becomes slightly supersaturated with respect to the oxalate of the metal and that at which precipitation of the metal oxalate is initiated. The mixture is then allowed to stand (either at room temperature or heated to elevated temperatures) for a period of time sufficient to form metal oxalate, and finally the formed metal oxalate is separated from the feed liquid to leave an aqueous liquid suitable for discharge to a sewer line.

Abstract: This invention involves a multi-step, multi-force process for dewatering sludges which have high concentrations of magnetic particles, such as waste sludges generated during steelmaking. This series of processing steps involves (1) mixing a chemical flocculating agent with the sludge; (2) allowing the particles to aggregate under non-turbulent conditions; (3) subjecting the mixture to a magnetic field which will pull the magnetic aggregates in a selected direction, causing them to form a compacted sludge; (4) preferably, decanting the clarified liquid from the compacted sludge; and (5) using filtration to convert the compacted sludge into a cake having a very high solids content.Steps 2 and 3 should be performed simultaneously. This reduces the treatment time and increases the extent of flocculation and the effectiveness of the process.

Abstract: An improved method for dewatering thin slurries of very fine clay or clay-like material to yield high solids content filter cake, for example, 40% solids and greater, by the use of flocculating agent combinations involving polyethylene oxide-type flocculating agents and polyacarylamide-type flocculating agents. The method generally involves admixing the combination of flocculating agents with the slurry, dewatering the slurry by means of a mechanical dewatering apparatus and feeding the thickened slurry to a belt press filter.

Abstract: The present invention solves the problem of managing resin-containing waste liquors within the cellulose pulp industry. The invention relates to a method for purifying resin-containing waste liquor in the manufacture of cellulose pulp, in which method a pH-adjusting chemical is, when necessary, added to resin-containing waste liquor removed from the cellulose pulps, so that the pH of the waste liquor will lie within the pH range 1-7, and in which a water-soluble organic polymer is added to the waste liquor in the form of a forwardly moving liquid stream. The method is characterized by dividing up the requisite amount of polymer into part quantities which are introduced into the liquid stream on at least two occasions, by subjecting the liquid stream to a pronounced shearing and/or turbulent treatment process, and by subsequently separating agglomerated resin from the waste liquor.

Abstract: A method of spreading a pulp for the purpose of drying it naturally, the pulp having a solid fraction which has a d.sub.80 of less than 100 microns. This method comprises the following steps:(a) adjusting the level of solids of the pulp to between 2 and 25%;(b) adding a flocculating agent to the pulp and mixing it with same, the amount of said flocculating agent being between two-thirds of 98% of the optimum required fo the flocculation of said pulp; and(c) spreading the mixture of pulp and flocculating agent, in the open air, in a bed the sides of which are permeable, and the bottom of which has a slope of less than 5 meters per 1000 meters, said spreading taking place 1 to 20 minutes after the adding are mixing of the flocculating agent.

Abstract: A process for clarifying and reclaiming industrial working fluids and/or outdoor working locations such as oil and gas well working fluids and pits. A treating agent is added to the fluid in an amount exceeding its solubility therein to precipitate soluble contaminants and to form a layer of treating agent over a lower layer of sludge at the pit bottom comprising insoluble contaminants and the precipitates. The layer of treating agent compresses the sludge and serves as a filter/barrier to increase the amount of overlying clarified fluid which can be collected. Following separation of the clarified fluid for disposal or reuse, the sludge is solidified by adding a further treating agent. The process is particularly suited for use in oil and gas well exploration wherein the treating agent is a particulate material including lime.

Abstract: A process for purifying an aqueous, hydrogen sulfide-scrubbing solution which contains a water-soluble transition metal component, such as a vanadium component or an iron component, in addition to at least one water-soluble organic compound, such as an aromatic sulfonate or an alkanolamine, in which the scrubbing solution is mixed with particles of a spent solid catalyst containing molybdenum and aluminum and a basic aqueous solution, preferably a solution comprising sodium aluminate, to form a slurry which is subsequently contacted with an oxygen-containing gas under conditions such that the molybdenum in the catalyst is solubilized. Thereafter, molybdenum is precipitated from the solution along with the water-soluble transition metal component and a wastewater substantially free of the transition metal component and the organic compound originally present in the scrubbing solution is recovered.

Abstract: Processes and techniques are described for treating waste water (domestic and industrial) to remove organic matter and heavy metals. Clay and flocculating agent are added to the waste water to cause separation of a sludge. The sludge is fired at high temperature in particle form to produce ceramic particles. Organic matter is oxidized; heavy metals are bound within the ceramic particles and cannot leach out. The ceramic particles are useful as aggregate (e.g., in concrete) and in landscaping.

Abstract: An automated, non-polluting process and apparatus for mechanically dewatering and heat drying liquid sewage sludge of widely varying solids content to form a pelletizable, dried sludge of predetermined uniform solids content without requiring recycling of previously heat processed sludge. Prior to being dried, the sludge is mixed with flocculation and coagulation promoting chemicals and is dewatered in a belt-type press. Drying takes place within an indirect heat dryer including an enclosed housing for capturing all gases and particles entrained in the gas driven off during the drying process. The gases and particles are advanced by means of a fan first through a cyclone separator for removing dust particles and next through a water jet scrubber prior to being exhausted or burned in order to control odor. The dust removed by the cyclone separator is recombined with the output from the indirect dryer prior to being pelletized.

Abstract: Method for dewatering sewage sludge with the aid of organic polymeric flocculating agents (polyelectrolytes) made preferably by emulsion polymerization. To obtain optimum dewatering results, a substantial amount of the aqueous phase of the sludge is removed by decantation after flocculant addition prior to the dewatering treatment proper. The flocculated and thickened sludge may then be dewatered much more quickly with the dewatering behavior improved additionally by causing a reactivating flocculation to take place on the delivery side of the sludge feed pump. The Figures show a preferred embodiment of the inventive sludge dewatering system using a recessed plate press.

Abstract: Carbon black and ash containing wastewaters from high-temperature processes in which the carbon black is present in an extremely finely divided and partly colloidal state are cleaned and disposed of by treatment with organic flocculants, predewatering of the flocculated suspension by gravity filtration and post-dewatering of the carbon black sludge by pressure filtration within the range from 0.5 to 15 bar in a process comprising adding sufficient calcium hydroxide to the wastewaters that the pH of an aqueous extract of the filter cake obtained is more than 11.8, preferably more than 12.0.

Abstract: A method of processing finely divided solids which have precipitated or separated out in a liquid. The suspended finely divided solid is converted into a pourable powder with negligible dust content and narrow particle size distribution, without detrimental particle alteration. The suspension is charged into a centrifuge, which may be a reversible-filter centrifuge. The solids are preferably centrifuged at a centrifugal pressure of 0.05-0.5 MPa for 0.5-5 min, and are then gently removed from the centrifuge, to be dried gently in a vibrating fluidized-bed dryer. The method is particularly suitable for processing precipitated synthetic rubbers (which may contain fillers as well) into a pourable powder which retains pourability after storage.

Abstract: A method for treating the combined ink and starch wastes from a paper converting plant by adding a cationic polymer flocculation adjuvant to the wastewater to form a sludge and then treating the sludge with a cementitious material to yield a stabilized solid safe for disposal by landfill.

Abstract: A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed.After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement.The concentrated liquid may also be dried into a powder using a thin film evaporator.

Abstract: A waste treatment method for metal hydroxide electroplating sludges. Metal hydroxide sludges from the treatment of electroplating waste waters are rendered environmentally safe. The sludges are first dewatered and heated to a temperature sufficient to cause the metal hydroxides to convert to metal oxides. Predetermined quantities of silica and soda, or sources thereof, are mixed with the metal oxides. The mixture is further heated to a temperature sufficient to cause fusion of the mixture and form a slag-like composition having the metal oxides in chemical solution. The slag-like composition is then cooled to ambient temperature. The structure of the cooled slag-like composition is predominantly crystalline, having the metal oxides in solid solution in either a precipitate phase or a silicate matrix. The slag-like composition is resistant to corrosion even in an acidic environment.

Abstract: A process for separating ash particles from an aqueous slurry containing a mixture of regenerated adsorbent (e.g., carbon) and ash particles includes the steps of settling the slurry to produce a solid phase including the mixture of adsorbent and ash particles and a supernatant or a clarified aqueous phase. After separation of the aqueous phase, a slurry of the solid phase is diluted with water and a dispersing agent for promoting suspension of the ash particles and an anionic polymer for promoting settling of the adsorbent particles are added. The thus-treated, dilute slurry is settled to produce an aqueous phase containing primarily suspended ash particles and a solid phase including carbon particles. After separation, the solid phase can be returned to a wastewater treatment system.

Abstract: An improved process for treating aerobic or anaerobic sewage sludge comprises a two-stage treatment with sulfur dioxides. In the first stage, between 25 and 40 pounds of sulfur dioxide per ton of dry sludge solids as reacted to optimize solids separation while substantially reducing coliform counts to acceptable environmental protection limits. Solids are separated and water discharged. Recovered solids are then treated with between 300-500 pounds of sulfur dioxide per dry solids ton to solubilize heavy, toxic and noble metals which may be recovered from the liquor. Separated sludge solids form a desirable and hazardous metal-free fertilizer.

Abstract: Aqueous mineral slurries containing 10% by weight or more of finely divided mineral solids are flocculated prior to dewatering and/or thickening to obtain improved throughput and/or to reduce moisture in the dewatered product, by treating the slurries with polymers comprising at least about 1% by weight 2-acrylamido-2-methyl propyl sulfonic acid copolymerized with acrylamide and/or other suitable water-soluble monomers. The polymers must have a Brookfield viscosity of at least 7000 cps at 7.5% concentration in water. Flocculation of the mineral slurries with these polymers also provides improved re-dispersibility of the dewatered mineral in the filter cake. During redispersion, additional dry mineral may be added to obtain a final solids content as high as 70% or more. The Brookfield viscosity of the final high solids slurry comprising a significant portion of filter cake treated with the flocculants of this invention is not detrimentally affected.

Abstract: For the purpose of increasing the efficiency during drying of brown coals having a high water content and for the purpose of facilitating the purification of process waste water resulting in a drying process according to Fleissner it is proposed to spray hot water onto the raw coal and to separate the proportion in fine grain having a maximum grain size of 5 mm, preferably of 1 mm. In the following, the proportion in fine grain is subjected to an adsorption stage (5), noting that after a reaction time of at least 1 min, preferably of 2 to 5 min, a major portion of the soluble substances burdening the waste water becomes adsorbed on this fine grain. Subsequently, the waste water is further purified after a flocculating step in a flocculating reactor (6) and after a separating step (8) for separating solid matter, for which purpose can be used sand filters (10), adsorbing resins and activated carbon.

Abstract: Wastewaters which contain carbon black and ash and originate from high temperature processes and in which the carbon black is present in a very finely divided state and partially in a colloidal state are treated and disposed of by a process in which the wastewater is treated with calcium carbonate or calcium hydroxide and an organic flocculant and subjected to a two-stage filtration and the resulting filter cake containing carbon black and ash is subjected to an aftertreatment with an aqueous iron salt solution.

Abstract: Method and apparatus for treatment of oilfield wastes, so that the wastes may be disposed of without harm to the environment or may be recovered as valuable products, wherein the wastes are pretreated to enhance separation of solid materials, the solid materials being dried and incinerated to a char solids condition, the char solids and the heating gases being cooled by heat exchange to provide hot air for combustion in the dryer-incinerator, thereby saving heating fuel cost, the gases being scrubbed to remove contaminants, and the condensed water-hydrocarbon phases being separated for reuse or for further treatment for recovery.

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

Abstract: The iron content of Bayer process streams is reduced by contacting said stream with a tertiary hydroxyl-containing polyamine.

Abstract: The following inorganic compounds of iron, when added to Bayer process liquors, form a precipitate of the finely divided iron present in:A. Ferric oxide;B. Ferrous salts; orC. Ferrous salts in combination with ferric oxide.The precipitate is removed using a polymeric flocculating agent. This treatment reduces iron levels below those obtained using other iron removal treatments.

Abstract: A method of treating wastewater containing a contaminant selected from the group consisting of heavy metal cations, tars, oils and phenols or mixtures thereof, comprising mixing said wastewater with an effective amount of desulfurization slag, the composition of said slag including calcium oxide, calcium sulfide and iron oxides, causing deposition of said contaminant from the mixture, and separating the deposit from the supernatant liquid.

Abstract: Redissolution and/or reoxidation of metals precipitated by chemical reduction from aqueous solutions can be prevented by adding a bicyclic, aromatic, organonitrogen compound to the solution in a amount insufficient to cause precipitation of said metal but sufficient to prevent the redissolution and reoxidation of the precipitate. The compounds added can be selected from benzotriazoles, benzothiazols and benzimidazoles.

Abstract: A coating composition for treating solid wastes is described and includes an aqueous silicate solution containing potassium oxide and silicon dioxide, a catalytic amount of an aqueous sodium borate solution and a fixative containing solid calcium oxide. A fumed silica may be added to either the aqueous silicate solution or sodium borate solution.

Abstract: A method is disclosed for the elimination of hazardous metal wastewater and sludges by recovering the non-ferrous metals zinc, nickel, copper (II), cadmium or chromium (III) present in an aqueous sludge comprising mixed metal hydroxides by selectively precipitating the ferrous metal ions present while maintaining the non-ferrous metal ions in solution, isolating the precipitate and then precipitating the non-ferrous metal ions from solution.

Abstract: Coal pulverized by a mill or crusher is used as a floating agent which is charged into a floating machine, together with wastewater, for example, from a wastewater treatment facility or homes which produce organic substances such as human wastes. The pulverized coal and wastewater are mixed and uniformly stirred by a stirrer in the form of an impeller or a cyclone separator while being aerated. The produced floating floc is discharged from an upper portion of a first floating machine, whereas sedimented materials are discharged from a lower portion of the first floating machine. The same process is repeated in other floating machines connected in series to the above-described first floating machine. The collected floating flocs are dewatered to produce solid cakes which are used as a fuel. The water which has been extracted to form the solid cake, is purified and discharged.

Abstract: Aqueous mineral slurries containing 10% by weight or more of finely divided mineral solids are flocculated prior to dewatering and/or thickening, and prepared for redispersion, by treating the slurries with polymers comprising at least about 1% by weight 2-acrylamido-2-methyl propyl sulfonic acid copolymerized with acrylamide and/or other suitable water-soluble monomers. The polymers must have a Brookfield viscosity of at least 7000 cps at 7.5% concentration in water. Flocculation of the mineral slurries with these polymers also provides improved re-dispersibility of the dewatered mineral in the filter cake. During redispersion, additional dry mineral may be added to obtain a final solids content as high as 70% or more. The Brookfield viscosity of the final high solids slurry comprising a significant portion of filter cake treated with the flocculants of this invention is lower than that of untreated material.

Abstract: A composition for protection of the liquid surface from heat- and mass-trfer, for example from evaporation, contains a polymer limitedly swelling in the protected liquid or a mixture of said polymer with a neutral filler having a density lower than the density of the protected liquid.A method for protection of the liquid surface from heat- and mass-transfer comprising application of said composition on the surface of a liquid, for example petroleum, in an amount of from 0.1 to 2 kg per m.sup.2. Upon contacting of the polymer with the liquid the polymer rapidly swells and forms a continuous gel-like covering which hinders the heat- and mass-transfer on the liquid surface.

Abstract: This invention relates to a process for removing nitrocresols and picric acid contaminants from a wastewater stream generated in the production of nitroaromatics, particularly dinitrotoluene, by the mixed acid technique. The process involves contacting the crude dinitrotoluene generated by the mixed acid technique with an alkaline medium to generate an alkaline wash water containing water soluble nitrocresols and picric acid therein. This wastewater is separated from the organic component and recycled for contact with further quantities of crude dinitrotoluene product from the reactor. When the concentration of the water soluble salts of nitrocresols and picric acid is of sufficient concentration the wash water is treated with aqueous acid in sufficient proportion to convert the water soluble salts to water insoluble organics. After treatment with acid, the organic material is separated from the wastewater and the organics incinerated.

Abstract: Sludge having a water content of less than 60% by weight is obtained by disintegrating primary dewatered sludge in a disintegrator to form sludge pieces having a layer of a dry dewatering additive while preventing the sludge from becoming like a slurry and then compressing the sludge pieces. The sludge thus obtained is combustible without requiring any further fuel.

Abstract: In the treatment of radioactive effluent it is known to produce a floc being a suspension of precipitates carrying radioactive species in a mother liquor containing dissolved non-radioactive salts. It is also known and accepted practice to encapsulate the floc in a solid matrix by treatment with bitumen, cement and the like. In the present invention the floc is washed with water prior to encapsulation in the solid matrix whereby to displace the mother liquor containing the dissolved non-radioactive salts. This serves to reduce the final amount of solidified radioactive waste with consequent advantages in the storage and disposal thereof.

Abstract: A method of spreading a pulp for the purpose of drying it naturally, the pulp having a solid fraction which has a d.sub.80 of less than 100 microns. This method comprises the following steps:(a) adjusting the level of solids of the pulp to between 2 and 25%;(b) adding a flocculating agent to the pulp and mixing it with same, the amount of said flocculating agent being between two thirds and 98% of the optimum required for the flocculation of said pulp; and(c) spreading the mixture of pulp and flocculating agent, in the open air, in a bed the sides of which are permeable, and the bottom of which has a slope of less than 5 meters per 1000 meters, said spreading taking place 1 to 20 minutes after the adding and mixing of the flocculating agent.