Abstract: An integrated process for heavy metal and cyanide removal in aqueous waste stream from plating processes wherein cyanide is oxidized by hypochlorite at approximately pH of 11.5 and hexavalent chromium is reduced to trivalent chromium at ambient temperature with ferrous sulfate at pH of 9.5; excess hypochlorite from cyanide destruction reacts with ferrous sulfate and additional ferrous sulfate is added to reduce hexavalent chromium to trivalent chromium to allow hydroxide co-precipitation with hydroxides of the ferric iron and hydroxides of copper, chromium, zinc, cadmium, manganese, etc., which are then separated by settling and filtration.

Abstract: A dewatering porocess and apparatus for recovering water from waste drilling fluid for concurrent reutilization in an active drilling operation includes a storage area, an intermixer for introducing treatment chemicals into the waste drilling fluid and a centrifuge. Flocculation is chemically induced in the waste drilling fluid as it passes through the intermixing means for introducing treatment chemicals into the waste drilling fluid. The waste drilling fluid is then transferred to the centrifuge wherein it is separated into solid waste and clear reuseable water. The water is returned to the storagge area and may be chemically adjusted prior to being returned to the drilling rig.

Abstract: In the Bayer process for producing alumina from bauxite of the type wherein the bauxite is added to a caustic solution to produce a soluble aluminate solution and an insoluble red mud fraction which is then subjected to one or more separation steps to produce a thickener overflow which is then subjected to a Kelly Filter Press to polish the thickener overflow the improvement which comprises treating the thickener overflow and the filter aid with a filtration improving amount of dextran.

Abstract: Sedimentation in an inherently colloidally stable mixture comprising a suspension of solids in a liquid is controlled by a five-step process. In the first step a mathematical model representing a relationship between certain parameters, namely area product, viscosity and a parameter related to zeta-potential, is created. In the second step, zones in the model in which there is undesirably high viscosity are identified, In the thrid step, a model sedimentation path which skirts the high viscosity zones is superimposed on the model. In the fourth step, the actual mixture under consideration is monitored during a sedimentation process to obtain actual measured values of any or all of the critical parameters. In the final step, the parameters are adjusted as necessary to fit actual measured values to values on the model sedimentation path.

Abstract: An aqueous suspension of minerals and/or fillers and/or pigments having a solid content .gtoreq.60% by weight, the mineral or the filler or the pigment being dispersed with one or more dispersing agents, is characterized in that the dispersing agent contains one or more amphoteric polyelectrolytes and/or cationic polyelectrolytes and/or amphoteric cationoic polyelectrolytes and/or amphoteric anionic polyelectrolytes and/or partially neutralized anionic polyelectrolytes and/or partially neutralized amphoteric anionic polyelectrolytes, the filler and/or pigment and/or mineral particles carrying a charge neutral or positive to the outside.Furthermore is disclosed a process characterized in that a part of the polyelectrolytes according to the invention is added before the grinding, a part thereof may be added during the grinding and a part thereof may be added after the grinding. According to the invention grinding and dispersing is achieved in only one process step.

Abstract: A method for treating muddy water which comprises adding a first chemical containing an alkali metal or alkaline earth metal oxide or hydroxide to muddy water to be treated, thereby rendering muddy water alkaline, adding a second chemical containing an anionic polymer coagulant to muddy water simultaneously with or after the addition of the chemical, further adding a third chemical containing a sulfate thereby rendering the muddy water weakly alkaline, and then adding a fourth chemical containing an anionic polymer coagulant to muddy water. As a result, large-sized and hard flocs are produced.

Abstract: A composition for the purification of water includes a suitable coagulant for coagulating solid impurities dispersed in the water to form flocs and an organic hydrophilic colloid capable, when dispersed in the water, of absorbing large quantities of water to form a sol for aggregating the flocs. The proportion of organic hydrophilic colloid in the composition is such that when the composition is used to purify the intended quantity of water, the organic hydrophilic colloid does not interfere with coagulant dispersal in the water or with floc formation.

Abstract: Techniques are described for extracting lead from a sample of potable water and analyzing for the amount of lead so extracted. A complexing agent is added to the water to form a complex with the lead. The water is then contacted with unmodified cellulosic or siliceous material on which the lead complex is retained. The complexed lead can be removed from the cellulosic or siliceous material with a weak acid. The amount of lead in the sample can be readily determined colorimetrically.

Abstract: A method for treating emulsified oil contaminants in the wastewater effluent of industrial and food processing operations. Cationic polymers and silicate ions are found to effectively coagulate the oily particles to facilitate removal from the water.

Abstract: A method of removing dissolved and colloidal macro-molecular organic substances from effluents from processes used in the manufacture of pulp and paper, wherein an acid sludge containing cellulose fibres and being acidified to a pH value of 1.6-2.5, is added to an effluent containing said organic substances, and the pH value is adjusted to 4.5-6.0 before the mixture is subjected to sedimentation to achieve precipitation of the fibres with said organic substances adhered thereto. According to the invention the fibres used as precipitant are subjected to mechanical treatment prior to said acidification, so that the fibres are broken and split open, increasing their specific fibre surface and thereby their ability to catch the organic substances in the effluent.

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: A method is shown for separating water from an oil-water system. A separator composition is blended from cactus extract, and activator and a carrier liquid. The separator composition causes separation of the oil and water into distinct layers which allows the water to be drawn off.

Abstract: A system and method for removing heavy metals, such as hexavalent chromium from water. The system comprises at least two reactor containers for independently mixing chemicals with water. The system further comprises a flocculator and a clarifier whereby each container can separately treat water therein and separately transfer the treated water to the flocculator such that water treated in batches at the containers can be treated in a relatively independent manner with relatively constant results. The method of chemically treating the water in the containers includes decreasing the pH value, adding a reducing agent and then increasing the pH value in preparation for precipitating the heavy metals in the clarifier.

Abstract: A process for clarifying liquors containing suspended solids is disclosed. The process is applicable to liquors having concentrations of suspended solids ranging from low to high, typically between 0.5 and 40 gm/l. The clarification process is characterized by the addition of flocculent and in excess of 50 gm/l inert particulate material so as to cause the formation of flocs comprising suspended solids and inert particulate material thereby to separate the suspended solids from the liquor. The inert particulate material is selected from silica sand, magnetite, limestone, ilmenite, hematite and calcite.

Abstract: A method for treating industrial waste water prior to its discharge into the city or county sewer system is provided. The method includes introducing into the waste water an iron-containing compound, a hydroxide and a flocculating agent. This method results in the formation of a sludge cake layer on top of the waste water. The sludge cake is then removed, and the treated waste water is discharged into the sewer system.

Abstract: Heavy metals can be precipitated from waste water or aqueous reaction solutions containing inorganic and/or organic complexing agents with substituted thiorureas of the general formula R.sub.1 R.sub.2 N-CS-NH-COR.sub.3. N,N-dialkyl-N'-benzoyl thioureas are used with preference, whereby methyl, ethyl, n-propyl or isobutyl groups are used as alkyl substituents.

Abstract: A method for removing iron(III), copper(II), zinc(I) and nickel(II) from an effluent containing chelant (EDTA, DEPA, HOEDTA) comprising treating the effluent with a soluble calcium compound (e.g., Ca(OH).sub.2) CaCl.sub.2, Ca(NO.sub.3).sub.2) in a molar equivalent to the chelant in combination with a monovalent hydroxide to a pH greater than 12.4 and then adding an effective amount of a dialkyldithiocarbamate (e.g.; sodium-N,N-diethyldithiocarbamate) to precipitate the metal hydroxides and nickel dialkyldithiocarbamate. Heating the solution to about 180 F. further speeds up the removal of the nickel(II). The nickel concentration of spent chelant cleaning solution can be reduced to less than 1 ppm.

Abstract: In a processing for treating waste containing effluent water from a food processing plant, the effluent water is contacted with a flocculant comprising a crude algal composition or a crude alkali processed algal composition obtained from algae selected from the classes Rhodophyceae, Cyanophyceae, Chlorophyceae and Phaeophyceae, at an acidic pH. A floc, which contains substantially all of the solid waste components of the effluent water, is formed as a result of the treatment process, and can be recovered for use in animal feedstocks or as other products such as fertilizers, or safely disposed of an in landfill operations. The clarified effluent water is sufficiently waste free that it can be forwarded to a secondary treatment facility or back into the food processing plant for reuse in certain plant operations.

Abstract: A method and a device of dividing an aqueous processing waste solution of a non-silver halide light-sensitive material into solid and water are disclosed comprising the steps of:(a) introducing said solution into an evaporator,(b) concentrating by heating said solution,(c) removing sludge produced from the evaporator during concentrating by heating said solution,(d) separating the sludge into solid and liquid and(e) cooling and condensing evaporated gas to liquid.

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: 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: A novel polymer and treatment scenario which considerably improves detackification of paint overspray consisting of high solids enamel, epoxy resin, or polyurethanes in the wash water or paint spray booths is disclosed comprised of:(i) a hydrophilic-lipophilic copolymer in combination with a modified tannin and/or(ii) a diallyldimethylammonium chloride polymer in combination with a modified tannin.

Abstract: Synthetic material apt to stably adsorb high quantities of heparin, consisting of a polyurethane resin, cross-linked with copolymeric chains in correspondence of at least part of its own urethane groups ##STR1## as per the following general formula: ##STR2## wherein, PU--- is a polyurethanic polymeric chain,R.sup.1 is an alkyl or aralkyl, containing functional groups inert to isocyanates,R.sup.2 is an alkylene,R.sup.3 is an alkylene, arylene or other bivalent organic radical, andR.sup.n is a polyamidoaminic radical;and process for the production of said material.

Abstract: Precipitation (conversion) of dissolved heavy metals in waste effluents is achieved with the addition and mixing of a solution of sodium polythiocarbonate with a solution containing dissolved heavy metals. The solution of sodium polythiocarbonate has been pH buffered to a pH of 12.5 or less in the manufacturing process. Precipitation of the dissolved heavy metals with the buffered sodium polythiocarbonate is complete by the formation of a stable, unleachable [as defined in 40 CFR 190.01, Part 261 Appendix II (Code of Federal Regulations)], extremely insoluble metallic polythiocarbonate particle.

Abstract: Removal of wet overspray from lacquer or similar water insoluble coatings by predominantly aqueous cleaning liquids is improved by including in the cleaning liquids as a coagulation agent a salt of a copolymer of ethylene and acrylic acid that contains 8 to 25% by weight of acrylic acid units and 92 to 75% by weight of ethylene units in its acid form. The cleaning liquid may be conveniently made by diluting an aqueous concentrate containing 2 to 25% by weight of the copolymer salt. Including cyanamide derivatives such as calcium cyanamide in the cleaning liquid further improves its coagulating effectiveness.

Abstract: A process is disclosed for treating food wastewaters by acidifying to a low pH, adding an alginate, and, preferably, adding lime to a pH of at least 7.0, without adding iron or aluminum to assist in coagulation and flocculation of the wastewater. A floc is formed at acid pH in some wastewaters and at neutral to alkaline pH in other wastewaters treated with lime. After recovery of the floc as a sludge, the process provides at least about 70% removals of Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) at reasonable costs and with negligible formation of free fatty acids in the resulting sludge.

Abstract: A method for clarifying water by liquid/solid separation comprising dosing the water to be clarified with a copolymer produced by the emulsion polymerization of only hydrophobic monomers where at least one hydrophobic monomer is an amine containing monomer which is hydrophobic when the amine is neutral and hydrophilic when the amine is salified.

Abstract: A process is disclosed for reducing the level of sulfides in aqueous solutiuons which comprises contacting a sulfide-containing solution having a pH value in the range from about 8.5 to 12 with oxygen in the presence of a flocculent manganese-containing catalyst having been prepared by aerating an aqueous solution of a divalent manganese salt, said salt solution having a pH value in the range from about 8.5 to about 12.

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 novel treatment scenario which considerably improves detackification of paint overspray consisting of undiluted high solids enamel, epoxy resin or polyurethanes in the wash water of paint spray booths is disclosed, comprised of (i) a dialkylamine-epihalohydrin in combination with a modified tannin and/or (ii) a dialkylamine epihalohydrin in combination with a melamine formaldehyde type polymer.

Abstract: A composition and method for detackifying paint spray booth water containing particles from paint spray is disclosed which uses a reaction product of an aldehyde with either a urea or an aminotriazine or both, and at least one of;(i) a hydrolyzed polyacrylamide;(ii) certain modified tannins in further combination with diallyldialkyl quaternary ammonium polymers or polymers derived by reacting certain dialkylamines with epihalohydrins.

Abstract: J-1 which is a strain of cyanobacteria is used to form and excrete a material useful as a floculating agent and as an additive useful in soil conditioning. Method of separating and culturing the cyanobacteria under conditions necessary to achieve maximum formation and excretion of the material into solution. Method of purifying and separating excreted as well as intracellular material from cyanobacterial. Method of clarifying a particulate-laden liquid with a material excreted by cyanobacteria, and particularly species J-1. Extracellular polymeric material which is water-soluble, non-dialyzable, having a molecular weight greater than 100,000, based on Sephadex column elution G 150, containing sugar, peptide, and fatty acid moieties, giving a positive Anthrone test, having an absorption peak of 205 nm. using a Perkin-Elmer spectrophotometer Model 402.

Abstract: Disclosed is a method for treating a photographic processing waste solution comprising concentrating the photographic processing waste solution containing at least thiosulfate ions, characterized in that there is provided at least one part selected from (i) to (v) shown below:(i) a part for adding sulfite ions or a compound capable of releasing sulfite ions into the photographic processing waste solution at the time or before heating of the photographic processing waste solution;(ii) a part for contact evaporated gas with a catalyst having a metal of the following (a) to (d) or a compound thereof carried thereon:(a) at least one selected from the group VIII elements consisting of iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum,(b) copper,(c) zinc,(d) manganese;(iii) a part for permitting a water-soluble polymer to exist;(iv) a part for permitting an oxidizing agent capable of oxidizing thiosulfate ions to exist; and(v) a part for adding a pH controlling agent into the photogr

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: A process for the purification of phenol-containing waters, in particular waste waters from phenolic resin production, where the term "phenol" is taken to mean all steam-volatile benzene derivatives according to DIN 38,409 H 16, by reaction of the phenol with formaldehyde in an alkaline environment at 50.degree. to 100.degree. C. to form those phenolformaldehyde condensates which, by subsequent acidification of the waste water, precipitate in filterable, granular and no longer sticky form and can be separated.

Abstract: An aqueous composition for conditioning an aqueous system, for example a sewage slurry, comprises an alkaline earth metal hydroxide, e.g. lime, and an anionic oligomeric polyelectrolyte, e.g. a salt of polyacrylic acid which composition has at least 40% by weight of particulate solid materials. Other components may include a weighting agent, e.g. calcium carbonate, a cationic flocculant, e.g. a polyacrylamide, and a base such as sodium hydroxide.

Abstract: We disclose a process for removing water-soluble organics from produced water. The process comprises: acidifying the produced water with acid; contacting the acidified with a free oil to form a mixture; agitating the mixture to produce a thoroughly mixed phase; and separating the phase to produce a free oil phase and a clean water phase.

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: Utilization of a cationic polymer as a settling aid in the recovery of the aluminum hydroxide and an anionic polymer to dewater the aluminum hydroxide prior to redissolution not only improves the process of making basic aluminum compounds by speeding settling and improving filterability, but also unexpectedly yields a product that has superior effectiveness as a water treatment chemical.According to the invention, a dilute solution of alum is neutralized with a base to a pH below about 6.0, preferably below 5.5, to form a suspension of aluminum hydroxide. A cationic polymer is then added to the suspension to assist in the settling of the aluminum hydroxide. When settling is substantially complete, the solution is decanted from the aluminum hydroxide and an anionic polymer is added to dewater the aluminum hydroxide. The dewatered material is collected as a filter cake containing amorphous aluminum hydroxide, the cationic polymer and the anionic polymer.

Abstract: A process for the treatment of aqueous effluent containing cyanide and toxic or heavy metals, wherein the effluent is contacted with a sufficient amount of hydrogen peroxide to oxidize at least a substantial portion of the cyanide in the effluent in the presence of sufficient trimercaptotriazine to react with a substantial portion of the metal present in said effluent, and precipitating said metal component.

Abstract: A process for removing metals from water including the steps of prefiltering solids from the water, adjusting the pH to between about 2 and 3, reducing the amount of dissolved oxygen in the water, increasing the pH to between about 6 and 8, adding water-soluble sulfide to precipitate insoluble sulfide- and hydroxide-forming metals, adding a flocculating agent, separating precipitate-containing floc, and postfiltering the resultant solution. The postfiltered solution may optionally be eluted through an ion exchange resin to remove residual metal ions.

Abstract: A process for treating a waste water containing uranium and fluorine comprises a neutralizing precipitation step wherein slaked lime is added to the waste water containing uranium and fluorine and precipitate thus formed in separated and removed, and an adsorption step wherein supernatant from the neutralizing precipitation step is contacted with a chelating resin which can selectively adsorb fluorine ions and another chelating resin which can selectively adsorb uranyl ions to thereby adsorb and remove the fluorine and uranyl ions remaining in the supernatant. Eluates of the ions adsorbed by the chelating resins and waste liquors for washing and regeneration of these resins are returned to the neutralizing precipitation step. Prior to the neutralizing precipitation step, a decarbonation step may be provided for decomposing carbonate ions, if they are contained in the waste water to be treated.

Abstract: A method of treating liquid wastes containing heavy metal chelate compounds which comprises reducing the pH of liquid wastes containing the heavey metal chelate compounds to 4 or less, adding iron polysulfate or at least one heavy metal ion selected from a source of Fe.sup.++, Fe.sup.+++, Cu.sup.++, Ni.sup.++ and Zn.sup.++ other than the iron polysulfate to form an iron chelate compound, then forming a solution containing Ca.sup.++ ions at pH 9 or more, and flocculating to precipitate thereby separating the resulting heavy metal hydroxides. The method gives a high heavy metal and COD removal rates, as well as showing good separability for flocks upon flocculating treatment.

Abstract: A process for treating effluent water of a poultry processing plant for reuse in that plant. According to the present invention, a treatment of the effluent with a strong oxidant and with a substance to reduce the pH to less than 5.2 pH units, and preferably about 3.0.+-.0.5 pH units causes a floc to form together with a destruction of bacteria and a breaking of the oils and greases. The floc contains the impurities such that the water separated from the floc is sufficiently purified for reuse in certain processing steps in the plant. In the case of treating effluent water from the poultry chiller tank(s), the product water can be reused in the tank(s). In the preferred form of the process, formation of the floc is enhanced by the addition of an anionic polymer or other thickener/strengthener, and separation is achieved by dissolved air flotation techniques. A final filtration can be utilized after a readjustment of the pH to near neutral to match new water to be used in the plant.

Abstract: A method of treating water comprises adding to the water a composition comprising a weighting agent and an electrolyte having a multivalent metal cation.The resultant floc absorbs suspended solids in the water and gives rise to a dense sludge which is easily removed from the purified supernatant liquor. A composition for use in the method is also disclosed. The composition may be in the form of a slurry or a friable solid (which may be briquetted).

Abstract: Methods are described for flocculating and removing solids suspended in water using an inorganic component containing iron, aluminum, or a mixture thereof in combination with a tannin-based flocculant produced by reacting a condensed tannin with an amino compound and an aldehyde. The tannin-based flocculant is preferably the product of a controlled reaction in which the viscosity is monitored as an indication of suitable shelf life.

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: A method for removing dissolved and colloidal material from the circulation water of a paper mill with chemical pulp fibers wherein fiber sludge which has been recovered from the paper manufacturing process and acidified to a pH of 1.5-2.5, is mixed with the circulation water of a paper mill whereby the dissolved and colloidal substances are precipitated.

Abstract: Heavy metals are removed from effluent waters using the sequential steps comprising:A. Adding a surfactant;B. pH adjustment;C. Adding a cationic coagulant;D. Adding a flocculant; and,E. Recovering the floc formed by the flocculant.

Abstract: A process is disclosed for the removal of metals from waters containing them, comprising the treatment of the waters with an aqueous solution of alkaline salts of humic acids, which is characterized in that said solution is obtained by the dry oxidation of coal by oxygen or mixtures of oxygen and nitrogen, in particular air, and the subsequent extraction of the raw oxidation product by an alkaline solution, and that said aqueous solution is added to into the waters as such, wherein the humic acids salts perform a flocculating action, with the end pH being preliminarily to a value comprised within the range of from 1.5 to 5.5.