Abstract: A method of treating mine drainage water including the step of adding a scale control agent to the mine drainage water and, optionally, adding an oxidizing agent to the mine drainage water and/or precipitating and settling the metals in their hydroxide form from the water. The treated water may be safely returned to the environment.

Abstract: Agents are used as cleaning agents and also as agents to purify the water in water treatment plants. The agents are a mixture of phosphates and fatty acid salts. Precipitation agents are used such as, polyvalent metals. The pH is adjusted. Flocking agents can be used to increase the rate of separation. The purified water is removed after precipitation.

Abstract: A method which uses a process reactor having three separate reaction stages to remove high concentrations of heavy metals from acidic wastewater and chemical solutions. During each of three stages the pH level of the wastewater is increased and sludge and flocculate organic and metal hydrocyl matters are removed from the wastewater to provide clean water which is discharged in to a sewer system.

Abstract: Disclosed herein is a method for dewatering sewage sludge by using sludge-coal-oil co-agglomeration (“SOCA”) which comprises the steps of physically, chemically or biologically conditioning sludge to impart hydrophobicity and lipophilicity to the sludge (conditioning step), supplying oil and coal to the conditioned sludge with stirring to form sludge-coal-oil agglomerates (agglomerating step), enlarging the particle diameter of sludge-coal-oil agglomerates (size enlargement step), and remaining the enlarged sludge-coal-oil agglomerates over a sieve to selectively separate them from hydrophilic materials dispersed in tailing water(screening step). According to the method, since sludge can be rapidly, easily and effectively dewatered and purified when compared to conventional sludge treatment methods. In addition, there is no risk of involving malodor and air pollution. Furthermore, the dewatered sludge can be utilized as a high-quality fuel.

Abstract: A process of flocculating and dewatering an aqueous suspension of suspended solids comprising, introducing into the suspension, (a) substantially linear polymer, (b) structured polymer, characterised in that the polymers are introduced into the substrate sequentially. The process brings about improvements in filtration.

Abstract: A method of treating liquid including mixing coagulant with the liquid, introducing mixed coagulant and liquid into a primary reaction zone, containing an agitator, of a reactor which is substantially concentrically positioned with respect to a secondary reaction zone of the reactor, introducing flocculant into the primary reaction zone at a location between the agitator and where the mixed coagulant and liquid are introduced into the primary reaction zone, mixing the mixed coagulant and liquid with the flocculant and causing the resulting mixture to flow into the secondary reaction zone, introducing an encapsulating agent into the secondary reaction zone, recirculating the liquid and encapsulated flocs through the primary and secondary reaction zone, and passing the liquid and encapsulated flocs outwardly of the reactor, and an apparatus for treating liquids including a reactor, a draft tube substantially concentrically positioned within the reactor and being positioned such that the liquids may flow inwardl

Abstract: A process is provided which can be used to clarify substantially aqueous streams and optionally separate biosolids, especially proteins, from food processing operations which comprises contacting an aqueous stream comprising biosolids with an anionic inorganic colloid and an organic polymer to flocculate the biosolids.

Abstract: An apparatus which uses a process reactor having three separate reaction stages to remove high concentrations of 3000 mg/l heavy metals from acidic wastewater and chemical solutions. During each of three stages the pH level of the wastewater is increased and sludge and flocculate organic and metal hydroxyl matters are removed from the wastewater to provide clean water which is discharged in to a sewer system.

Abstract: A clarification system for fluids in which particles are separated from the fluid by flotation and in which the buoyant media inducing the flotation is recycled. Flotation can be assisted by a flotation assistance device, such as dissolved air flotation.

Abstract: Systems and methods for polymer addition control for sludges from water and wastewater treatment. In a treatment process where flocculating agents are used to promote solids aggregation, intrinsic physical properties of the liquid rich stream following separation may be continuously measured in order to control or optimize the amount of flocculating or treatment agent that is added to the process. These intrinsic physical properties may include, for example, the flocculating suspension or network strength. By determining the floc strength using various treating agent dosages, a optimum treating agent dose can be determined. The optimum treating agent dosage is the minimum in a floc strength to polymer dose curve.

Abstract: A method for removing metal contaminants from acidic mine wastewater using lignin derivatives, such as lignosulfonates and kraft lignin, an alkali coagulant, such as a lime compound, and an alkaline composition for increasing the pH. The lignin derivatives are dispersed in the wastewater and the coagulant is added, increasing the pH to about 4.5–8.5 and causing the formation of a floc. The alkaline composition is then added to bring the pH to about 9 to 10, causing the further formation of a floc. Optionally, air oxidation is carried out, reducing the pH to about 8.1–8.6. Optionally, a ferric or ferrous salt may also be added. The flocs comprise metal-lignin colloids, metal hydroxides and metal salts. The flocs coagulate to form a sludge. Optionally, fly ash or diatomaceous earth may be added to increase the density and stability of the sludge. The sludge that is formed contains the metals and is separated from the treated water by filtration.

Abstract: A method for removing metal contaminants from water uses lignin derivatives, such as lignosulfonates and kraft lignin, a coagulant, such as a metal salt, and a pH-increasing composition. The lignin derivative is dispersed in the contaminated water, the coagulant is added and the pH is adjusted as required to cause flocculation. A sludge is formed that contains the metals and that is separated from the treated water by filtration. Related methods are used to reduce the leachable metal content of contaminated soils. The invention also provides a composition for stabilizing the metal contaminants in soil, comprising lignin derivatives, a coagulant and a composition for increasing the pH. The mixture is blended with the contaminated soil, reducing its leachable metal content.

Abstract: Pollutants, such as heavy metals, phosphorus, and pathogenic organisms, are removed from water by adding a chemical coagulant to the water within an enclosure. The water and the coagulant are mixed, and coagulation and flocculation are permitted to occur. The mixing is stopped, and a floc is permitted to settle to the enclosure bottom. The floc contains the pollutant; so the treated water above the floc is free from at least some of the pollutant. At least some of the treated water is removed from the enclosure, and new water is added to the enclosure. The new water and the settled floc are mixed to resuspend components of the floc. The process is repeated for multiple iterations, until the floc no longer exhibits contaminant-removal capability, at which time the floc is removed from the enclosure.

Abstract: A method of treating an oil-containing waste water includes adding, where the waste water has been adjusted to have a pH between eight and twelve and have a temperature not higher than 50° C., a high-cationic flocculant consisting of a high-molecular material selected from among acrylamide-quaternized or salified dimethylaminoethyl acrylate or methacrylate copolymer, and acrylamide-quaternized or salified dimethylaminoethyl acrylate or methacrylate-acrylic acid copolymer, and which constitutes a plurality of polymerized units at least 60 mol % of which have respective cationic functional groups, to the waste water, such that a concentration of the flocculant in the waste water falls between 100 mg/L and 1,000 mg/L, so that at least one fouling component dispersed in the water is flocculated to form a sludge consisting of flocks of the at least one fouling component and thereby separate the at least one fouling component and the water.

Abstract: A method of oxidation or pathogen inactivation in water supplies using the combination of treatments of chlorine dioxide and ozone in the sequential steps prior to filtration and distribution. Results indicate that the addition of chlorine dioxide before prezonation reduces the bromate formation and chlorine dioxide can be substituted for preoxidation with ozone, while maintaining the enhanced filtration effects observed from the presence of a preoxidant. A majority of the chlorite formed from reactions of chlorine dioxide with constituents in raw water are converted to chlorate by the following ozonation step.

Abstract: The invention relates to a method for treatment of water, permitting the physico-chemical treatment of water, including a ballasted flocculation stage using a granular ballast material with a density greater than water, followed by, a stage of gravity separation of the treated water and the flocculent mass, a stage of separation of the granular material, recycled for the flocculation stage and the muds. Said muds are sent to a stage for treatment of the muds, characterised in comprising a stage in which the functional mode passes from a mode using ballasted flocculation and gravity separation using coagulation and flocculation reagents to a mode functioning by simple gravity separation, without using coagulation and flocculation reagents. The passage from one mode to another is determined using at least one item of information on the water obtained at any stage of the treatment thereof or before said treatment.

Abstract: A method of dewatering an aqueous mineral suspension comprising introducing into the suspension a flocculating system comprising, a) a substantially non-ionic polymeric flocculant and b) an anionic polymeric flocculant, characterised in that, the substantially non-ionic polymeric flocculant is added to the suspension before the addition of the anionic polymeric flocculant. The method is useful for flocculating China clay suspensions, suspensions of s welling clays, calcium carbonate suspensions, titanium dioxide suspensions, suspensions of coal tailings, red mud and phosphate slimes etc.

Abstract: A method is provided for thickening sludge produced through a ballasted flocculation process. The sludge and granular material from the ballasted flocculation process are directed to a sludge separator where the sludge is separated from the granular material. Thereafter the separated sludge is sent to a degassing area and the sludge is degassed. A flocculating agent is mixed or injected into the sludge. The sludge is directed to a sludge thickener with a load at a sill calculated on the surface of the thickener greater than 200 kgMIS/m2/day. This process produces a thickened sludge having a concentration greater than 10 gm/I.

Abstract: A method of treating mine drainage water including the step of adding a scale control agent to the mine drainage water and, optionally, adding an oxidizing agent to the mine drainage water and/or precipitating and settling the metals in their hydroxide form from the water. The treated water may be safely returned to the environment.

Abstract: A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation” technology such as magnetic separation, dissolved air flotation, vortex separation or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used.

Abstract: A method and apparatus is described for separating contaminants from waste material including waste water derived from a chemical processing or manufacturing plant, such as the waste water from a coconut processing plant. The separation method and apparatus involves the use of a mixer to aerate a partially treated waste water material prior to mixing the aerated material with a new supply of waste water to aerate the waste water feed supply for admission to a separation vessel in which the contaminants of the waste water are collected as sludge at the top of the aerated zone for disposal. The treated waste water now substantially free of contaminants is collected in a clean zone for discharge or recirculation. Prior to discharge the partially treated waste water in the clean zone can be recycled through a recirculation loop containing the mixer. The recirculation loop can be operated independently of the rate of supply of new waste water.

Abstract: A mobile apparatus and method for recycling an invert emulsion based drilling fluid, in which the invert emulsion based drilling fluid includes an oleaginous component and an aqueous component. The apparatus includes an emulsion breaking tank, a water treatment tank, a filter press, and hydrocarbon filters. The method includes: mixing said invert emulsion drilling fluid with a emulsion breaker, wherein the emulsion breaker is a mixture of an alkyl glucoside and an alkane sulfonate; and separating the oleaginous component of the invert emulsion drilling fluid from the aqueous component of the invert emulsion drilling fluid. The method preferably utilizes an emulsion breaker that is a combination of an anionic surfactant, a nonionic surfactant and an alkyl polyglycoside surfactant.

Abstract: Animal waste such as fecal material from swine, chicken, turkey, and cattle is converted into useful forms such as fertilizer, other types of soil builders, and even nutrient feed additives. Devices, systems, and methods are provided that allow economical conversion and in many instances, alleviate the production and release of undesirable gases such as sulfide and ammonia. In one embodiment, undesirable anaerobic and facultative anaerobic bacteria are killed at a greater rate than desirable soil compatible aerobic bacteria. The use of low temperature killing diminishes off gassing commonly associated with other techniques, and the use of gas trapping additives such as zeolites provides enhanced soil building qualities such as slow release of nitrogen and slow release of moisture to soil. The methods allow convenient adjustment of composition, allowing conversion of waste into tailored designer fertilizer suited for particular soils.

Abstract: A new method of improving the process of dewatering fine particulate materials is disclosed. In this method, an aqueous slurry of fine particles is treated with appropriate hydrophobizing reagents so that the particulate material becomes moderately hydrophobic with its water contact angle considerably below 90°. A low hydrophile-lipophile balance (HLB) number surfactant is then added to the slurry, so that the surfactant molecules adsorb on the moderately hydrophobic surface primarily by hydrophobic attraction and, thereby, increase its contact angle close to or above 90°. By virtue of the greatly enhanced hydrophobicity, the water molecules adhering to the surface are destabilized and removed more readily by a mechanical dewatering process. Any nonionic surfactant with its HLB number below about 15 may be used for the hydrophobicity enhancement. The surfactants may be used in conjunction with appropriate solvents such as light hydrocarbon oils and short-chain alcohols.

Abstract: The invention relates to a process for treating a chromate waste liquid containing an organic acid component. This process includes (a) adding a chromium precipitation accelerating agent containing at least one of a calcium component and a magnesium component, to the chromate waste liquid; and (b) adjusting the chromate waste liquid to having a first pH of 9 or higher, thereby precipitating a chromium component from the chromate waste liquid and thereby reducing a concentration of a dissolved chromium component of the chromate waste liquid.

Abstract: The present invention provides a process and an additive package for removing oil from solid material recovered from a well bore, e.g., drill cuttings and produced sand. In this process, the solid material is passed from the well bore to a separation zone. An aqueous acidic solution containing a polymer substituted with an amino group is introduced to the separation zone containing the solid material along with a halogenating agent and optionally one or more surfactants. The polymer, halogenating agent, and optional surfactant constitute the additive package. The polymer substituted with an amino group is preferably chitosan, and the halogenating agent is preferably a sodium hypochlorite solution. The mixture formed in the separation zone is agitated to cause a product of a reaction between the polymer and the halogenating agent to contact the solid material and remove residual oil therefrom.

Abstract: A method of treating spent alkaline pulping liquor (black liquor) includes the steps of providing black liquor containing lignin, and acidulating a phosphate containing material, wherein phosphoric acid is generated by the acidulating step. The black liquor is mixed with phosphoric acid from the acidulated phosphate containing material, wherein lignin is separated and clarified liquor results. The method can include the step of adding a water soluble, surface active, polymeric, coagulant agent to the black liquor before mixing with the phosphoric acid from the phosphate containing material. The clarified liquor comprises anion species including phosphate.

Abstract: In one aspect the present invention provides purification devices for reducing the amount of contaminants in water, each device includes a water-soluble flocculant disposed within a body defining a multiplicity of pores, wherein the pores have an average diameter in the range of from 1 &mgr;m to 2000 &mgr;m. The present invention also provides methods for reducing the amount of contaminants in water.

Abstract: A method for recovering and separating precious and non-precious metals from waste streams, which removes, separates, and recovers such metals in a cost effective manner with more than 95% removed from waste streams and with minimal amounts of unprocessed solids and sludge remaining in the environment. Metals such as chromium, manganese, cobalt, nickel, copper, zinc, silver, gold, platinum, vanadium, sodium, potassium, beryllium, magnesium, calcium, barium, lead, aluminum, tin; and the like are removed and recovered from the waste streams with at least 95% removal and other metals and compounds, such as antimony, sulfur, and selenium are removed and recovered from waste streams with at least 50% removal. The method employs a unique complexing agent comprising a carbamate compound and an alkali metal hydroxide which facilitates the formation of the metals into ionic metal particles enabling them to be readily separated, removed and recovered.

Abstract: A process is provided which can be used to treat aqueous streams comprising soluble biomaterials, especially proteins, wherein the concentration of soluble biomaterials is substantially reduced. The process comprises adjusting the pH of a substantially aqueous to less than or equal to pH 3 to produce a first pH-adjusted stream, which is in turn adjusted to greater than pH 3 to produce a second pH-adjusted stream followed by addition of a flocculant to produce a flocculated material.

Abstract: A process for treating liquid septage and other biosolids having the steps of placing a known amount of liquid septage in a tank, mixing in a sufficient quantity of alkaline material to raise the pH to a desired level, flocculating the septage, storing the pH adjusted septage for a predetermined period of time, thickening the septage, de-watering the septage, and pasteurizing the resultant liquid effluent and de-watered solids cake. The process for treating liquid septage and biosolids disclosed by the current invention meets the Class A vector attractant reduction and pathogen reduction requirements mandated by the U.S. EPA. The end product of septage and other biosolids treated using the process disclosed by the current invention can be sold as fertilizer, and utilized without any additional permits.

Abstract: A method for reducing the toxicity of onium compounds, such as ammonium compounds and phosphonium compounds, by the use of certain additives is described. Suitable additives include, but are not necessarily limited to, carboxylic acids (e.g. naphthenic acids), sulfonic acids, organophosphonic acids, phenolic compounds, ether sulfates, phosphoric acid esters, sulfonated fatty acids, sulfated fatty acids, oligocarboxylic acids, and mixtures thereof, and alkali metal salts of these compounds and amine salts of these compounds.

Abstract: A process for recovering fine coals and clarifying water for recycling features with three distinct mechanisms: hydrophobic extraction, electrolyte coagulation, and macromolecular flocculation, which if desired may be integrated into a single stage. The hydrophobic extraction is accomplished using oil to form a coal-in-oil mixture. The process water is clarified using a flocculants, more preferably a combination of coagulant and anionic flocculants. With a well defined reagent addition scheme, this process allows a combustible recovery greater than 88% at an ash content less than 11%, while producing a clean water containing less than 20 ppm suspended solids from a tailing's stream. The coal-in-oil mixture may be used as a fuel for example in coal-firing boilers and power generators.

Abstract: The present invention relates to anaerobic curing impregnation sealant compositions which are readily separable from water upon mixing.

Abstract: A process and system for removing animal processing contaminants and fats, oils, and greases from large volume quantities of waste water. In the process, a waste water stream containing the contaminants is treated with a chemical oxidant, polymer compound and coagulant to create a particle having a diameter greater than 50 microns. Treated waste water is passed through a microfiltration membrane which physically separates the contaminant particle from the waste water. Commercially available microfiltration membranes having a pore size in the range of 0.5 micron to 10 microns may be used. The treated waste water flow rate through the microfiltration membranes can range from at least 200 gallons per square foot of membrane per day (“GFD”) to in excess of 750 GFD. Solids are removed from the membrane surface by periodically backflushing the microfiltration membranes and draining the filtration vessel within which the membranes are located.

Abstract: An environmentally friendly method and composition is provided for removing hydrogen sulphide from fluids at high pH. The method and composition are particularly suited for removing hydrogen sulphide from drilling fluids used in drilling boreholes in hydrocarbon bearing subterranean formations, and are suitable for use with any drilling fluid, including polymer based drilling fluids. The sulphide scavenger used in the method and composition is a ferrous gluconate, an organic iron chelating agent stable at pH as high as 11.5, the pH preferred for drilling fluids that may encounter hydrogen sulphide. Further, this additive has been found to enhance the resilience of the rheological properties of drilling fluids to hot rolling and comparable field conditions.

Abstract: A method of dewatering sludge comprising adding an effective amount of one or more cellulolytic enzymes, one or more oxidants and one or more flocculants to the sludge to form a mixture of water and coagulated and flocculated solids and separating the coagulated and flocculated solids from the water.

Abstract: This invention concerns a method of dewatering sludge comprising adding an effective amount of one or more cellulolytic enzymes and one or more peroxidases to the sludge.

Abstract: The claimed invention is a method for separating Bayer process red mud from a Bayer process liquor which comprises adding to a Bayer process liquor containing red mud an effective amount of a water soluble synthetic flocculant, dextran and starch combination. The flocculant is added anywhere in the slurry containing the red mud suspended in Bayer process liquor, or in a liquor slurry containing bauxite prior to or during digestion. Once the flocculant combination is added, it is mixed sequentially with the Bayer process liquor and the red mud contained in the Bayer process liquor is removed by sedimentation, centrifugation or filtration.

Abstract: A method for reducing the toxicity of onium compounds, such as ammonium compounds and phosphonium compounds, by the use of certain additives is described. Suitable additives include, but are not necessarily limited to, carboxylic acids (e.g. naphthenic acids), sulfonic acids, organophosphonic acids, phenolic compounds, ether sulfates, phosphoric acid esters, sulfonated fatty acids, sulfated fatty acids, oligocarboxylic acids, and mixtures thereof, and alkali metal salts of these compounds and amine salts of these compounds.

Abstract: A method of dewatering an aqueous mineral suspension comprising introducing into the suspension a flocculating system comprising, a) a substantially non-ionic polymeric flocculant and b) an anionic polymeric flocculant, characterised in that, the substantially non-ionic polymeric flocculant is added to the suspension before the addition of the anionic polymeric flocculant. The method is useful for flocculating China clay suspensions, suspensions of s welling clays, calcium carbonate suspensions, titanium dioxide suspensions, suspensions of coal tailings, red mud and phosphate slimes etc.

Abstract: In the typical embodiments disclosed in the specification, a ballasted flocculation liquid treatment arrangement includes a mixing chamber in which liquid to be treated, flocculating agents and granular material are mixed. The mixture is supplied to the bottom of a flocculating chamber adjacent to the mixing chamber through an opening in a common wall between the chambers and is maintained in suspension in the flocculating chamber by turbulence generated by a rotating blade array. Ballasted flocs are transferred from the flocculation chamber to an adjacent sludge tank through a first opening in a common wall between them and liquid which contains lighter flocs is returned to the flocculation chamber through a second opening in the common wall. Liquid from the flocculation chamber passes upwardly through a turbulence control arrangement where flocs and particulates are substantially removed and into a clarification chamber where clarified liquid is passed over a weir to an outlet.

Abstract: A Method of treating sludge prior to dewatering by mixing with the sludge a cationic metal in the form of an iron or aluminum slat along with a cationic polymer. The addition of the iron or aluminum salt substantially reduces the amount of polymer required for acceptable dewatering, thusly significantly reducing the cost of the dewatering process. The method is enhanced by subjecting the prior digested sludge to mesophilic aeration prior to the cationic metal salt and polymer being added.

Abstract: The precipitation and removal of suspended fat and protein components and other suspended solids from a given solution can be accomplished by the addition of an aluminate to complex with the fat and protein components and the addition of a flocculating agent to flocculate the aluminate/fat and protein component complexes into insoluble particles capable of removal by conventional technology, which insoluble particles can be rendered to produce tallow.

Abstract: A process for dewatering and reducing pathogens in liquid waste sludge having a liquid component and a sludge solids component. Alkaline material is added to the liquid waste sludge. Flocculent may then be mixed with the liquid waste sludge. The liquid waste sludge is then fed into a screw press having a screw. The screw simultaneously heats and dewaters the liquid waste sludge for a sufficient period of time and at a predetermined temperature for the sludge solids component from the screw press to be pasteurized. An apparatus is also provided for carrying out the process for dewatering and reducing pathogens in liquid waste sludge.

Abstract: The invention concerns a flocculation-decantation method by ballasted flocs using a granular material and a step which consists in treating the sludge derived from flocculation-decantation in a circular grit trap wherein the auxiliary liquids tangentially injected into the sludge substantially in the same direction as the latter. The invention also concerns a circular grit trap with a cylindrical part of diameter D tangentially supplied with the suspension to be treated and a conical part and provided with a cylindrical chamber injecting wash-water provided at the conical part outlet and having a diameter D′ ranging between 0.35 D and 0.65 D, said cylindrical chamber having at least a tangential supply of auxiliary liquid along the same feeding direction as said tangential supply of the suspension to be treated.

Abstract: Disclosed is a method of removing heavy metals contained in exhaust gas which has been generated by burning a waste liquid containing the heavy metals discharged in a process of producing organic compounds. The method includes the steps in the order of: (a) a combustion step of burning the waste liquid to produce exhaust gas; (b) a gas-liquid contact step of rendering a liquid containing an alkali compound in contact with the exhaust gas to collect the heavy metals in bottoms of the liquid; and (c) a coagulating step of adding a coagulant to the bottoms to coagulate the heavy metals in the bottoms for removal of the heavy metals. According to this method, the heavy metals contained in the exhaust gas can be efficiently separated and removed.

Abstract: The present invention is a floatation process and associated apparatus for removing heavy metal waste from various effluent water streams. The process and apparatus generally introduces a population of fine diameter air bubbles and one or more flocculating chemicals into an effluent stream to produce buoyant floc structures that include the heavy metals and that can be removed from the effluent stream. The present invention provides a reliable, cost-effective means of removing heavy metals from effluent water streams.

Abstract: Aqueous suspensions of paints in waste waters can be treated to detackify the paint and facilitate its removal by contacting the paint suspension at a pH of from about 5 to about 14 with a polyarylamine that is produced by reacting an aldehyde with an arylamine in the presence of an acid in an aqueous suspension. The same polyarylamine can also be used for reducing the color content of highly colored liquids. Compositions containing the polyarylamine are also described.

Abstract: A method of removing lead from water comprising a) adjusting the pH of the water to about 7 to about 9; and b) adding to the water an effective amount of a water soluble, high molecular weight cationic dispersion polymer composed of i) (meth)acrylamide; ii) a hydrophilic cationic monomer of formula  wherein A1 is O or NH; B1 is C2-C4 alkylene or hydroxypropylene; R1 is H or CH3, R2 and R4 are independently C1-C2 alkyl; R3 is H or C1-C2 alkyl; and X1 is an anionic counterion; and iii) a hydrophobic cationic monomer of formula  wherein A2 is O or NH; B2 is C2-C4 alkylene or hydroxypropylene; R5 is H or CH3; R6 and R8 are C1-C2 alkyl; R7 is C6-C20 alkyl or arylalkyl; and X2 is an anionic counterion; c) optionally adding a water soluble ethylene dichloride ammonia polymer to form a mixture of water and lead-containing flocculated solids; and d) separating the lead-containing flocculated solids from the water.