Abstract: Chloride is selectively isolated as NaCl from N-phosphonomethyliminodiacetic acid process wastes by evaporative crystallization of the caustic neutralized brine.

Abstract: The present invention relates to a process for treating a wastewater comprising an ammonium ion species and a phosphorus ion species. The process comprises the steps of: (i) treating the effluent in a first stage of the process to convert the phosphorus to a phosphorus-containing salt; (ii) treating the wastewater in a second stage of the process to convert the ammonium ion species to gaseous ammonia; (iii) removing the struvite and/or other phosphorous containing salts from the effluent; and (iv) removing the gaseous ammonia from the wastewater.

Abstract: A water soluble, surface active, polymeric agent is mixed with digestion liquor, preferably with an additional surface active defoamer coagulant agent prior to or during acidification of the alkaline digestive liquor. This results in an easily separable, non-gelatinous, non-gummy, coagulated lignin as a solids, particulate fraction that tends to float on a clarified liquid fraction containing recoverable salts. The solids fraction and the liquid frictions are easily separated, one from the other, by a gravity separation step.

Abstract: A method is taught for converting metal contaminants in the soil to less toxic forms as well as permitting their removal from groundwater. A first reactive solution comprising ferrous sulfate and an acid selected from the group consisting of sulfuric acid and phosphoric acid is injected to decomplex contaminants and precipitate them as insoluble compounds. A second reactive solution comprising hydrogen peroxide, and an acid selected from the group consisting of sulfuric acid and phosphoric acid is then injected to destroy organic liquids and enhance decomplexation. The pH of the first solution may range from 3 to 5, and the pH of the second solution range from 3 to 7, preferably 5 to 7. The process is particularly effective where chromium compounds such as hexavalent chromium are the contaminants.

Abstract: Phosphate-contaminated water passes through a domestic sewage treatment system, in which oxidation of the ammonium progresses far enough to cause a lowering of the pH to 5 or less. The water is passed over sand grains coated with aluminum hydroxide (gibbsite). Enough Al3+ ions enter solution, at the low pH, to cause all the phosphate-P to precipitate as aluminum phosphate, and nothing else precipitates other than the aluminum phosphate.

Abstract: A method of removing arsenic and fluoride from aqueous solutions in the same process is provided. Specifically, the pH of the aqueous solution is adjusted to a pH in the range of about 5 to 8. A combination of calcium salts, and ferric or aluminum salts are added to form insoluble arsenic and fluoride bearing solids. The solids are then removed from the aqueous solution.

Abstract: The invention provides a method treating acid raw water including the step of neutralising the water by adding calcium carbonate to it in a neutralising stage. The neutralised water is then rendered alkaline or more alkaline by adding an alkali thereto selected from calcium hydroxide, calcium oxide and mixtures thereof in a lime treatment stage. The alkaline water is then treated with carbon dioxide in a carbon dioxide treatment stage, with the carbon dioxide reacting in the carbon dioxide treatment stage with calcium hydroxide dissolved in the water.

Abstract: A method is disclosed for treating a flushing solution from an ion exchanger used in electroplating operations by co-precipitating or selectively precipitating out metal hydroxides derived from metal ions from the structures being plated in the electroplating bath, metal ions from the electrodes use in the electroplating bath and metal ions from the plating metal used in the electroplating bath, and a pH raising agent having a cation with a valence of at least 2. After the metals are precipitated out of the flushing solution, the flushing solution is aerated with carbon dioxide to precipitate out the cation from the pH raising agent as a carbonate. The carbonate precipitate is removed from the flushing solution and the resulting solution consists essentially of water that may be recycled for use in the electroplating plant or safely discharged into the environment.

Abstract: The presently disclosed disinfection process for use in the processing of foodstuffs is designed as an intervention step in poultry processing to allow for continuous on-line processing of poultry carcasses that may have accidentally become contaminated during the evisceration process. Such on-line processing is designed to replace the need for off-line manual washing and cleaning of the contaminated carcasses. By eliminating such off-line manual washing, food safety will be enhanced due to the elimination of the physical handling of carcasses and the cross-contamination that may result from such physical handling. An additional benefit is that the production process will also be able to run with a reduced number of interruptions, which will result in a more efficient production process.

Abstract: The presented invention discloses a process to remove low or high concentrations of common or complexed heavy metals from aqueous solutions as well as oily solutions. The process uses a product (8856A), which is a mixture of 80% phosphoric acid (75-80%) and 20% aluminum sulfate (48%). The percentage of aluminum sulfate in 8856A is very critical in providing optimum solid-liquid separation in the settling stage and removing any excess phosphates from the discharge. Heavy metals such as iron, copper, nickel, zinc, chromium and lead are precipitated as metal phosphates. The process is capable of removing all of the metal in the solution because it discloses a longer detention time of two to four hours, which provides sufficient time to breakdown any complexing agents preventing precipitation of the metal. According to the presented invention, metal concentrations in the treated wastewater are decreased to levels below the detection limits.

Abstract: This invention provides a method for reducing phosphorous in a body of water. This method comprises calcining a plurality of rocks and collecting carbon dioxide formed as a result of the calcining process; crushing the plurality of calcined rocks; pumping source water from the body of water into to a plurality of retaining cells; flocculating the phosphorus in the source water by introducing the plurality of calcined rocks into the source water in the retaining cells; settling out a phosphorous precipitate formed by the flocculating act; adjusting the pH level of the flocculated source water to a predetermined range of values by pumping carbon dioxide created by the calcining of the rocks into the source water to created treated water; and transferring the treated water back to the body of water.

Abstract: This invention relates to a process for treating an effluent comprising a mixture of spent wash and black liquor, said process comprising mixing the effluent with a flocculating agent consisting of a mixture of salts of Group III and transition metals, mixture of natural earth's along with an oxide of alkaline earth metal followed by treating with a combination of ion exchange resins.

Abstract: The present invention discloses a process and an apparatus for removing deep sub-micron particles from water. The invented process includes adjusting pH value and conductivity, adding an oxidation agent, performing an electro coagulation reaction/an electro-oxidation reaction, and performing a flocculation sedimentation, etc. The invented apparatus includes a front adjustment tank for adjusting the properties of waste water, wherein the adjustment includes a pH adjustment, an electrolyte adjustment, or an oxidant addition, etc.

Abstract: A method of controlling algae in a municipal water plant including the step of adding an algicide-flocculant solution including 25-50 wt % acidic flocculent, 0-10 wt % polymer flocculant aid, an algicide consisting essentially of copper having a concentration of 0.025-1.275 wt % in the form of a water soluble copper salt, balance water. The algicide-flocculant solution may be added to the water via a clarifier of the water plant, a basin of the water plant, or a mixing chamber. The mixing chamber may be located within the clarifier, adjacent to the basin, or upstream of the clarifier and/or the basin.

Abstract: In the purification of deicing fluid for recovery of glycol, initially solid particles are separated, then dissolved organic compounds and positive and negative ions are separated by an ion exchange in an ion exchanger, and finally water is separated by distillation.

Abstract: A method for the conditioning of phosphoric acid containing solutions is described, wherein the solution is converted to a solid material by adding an aluminum compound. This solid material can readily be stored in disposal sites because it is not water-soluble. This method is particularly suited for the conditioning of phosphoric acid containing solutions from metal processing. An apparatus (10) for carrying out the method comprises a mixing tube (12) with a longitudinal axis (M) as well as an inlet (14) and an outlet (16). At least two liquid supply nozzles (18 and 20) opens into the mixing tube inlet (14) and, with respect to the inlet cross-sectional area of same, into a central area. Moreover, at least one gas supply nozzle (22) which is arranged radially outward of the liquid supply nozzles (18 and 22) opens into the mixing tube inlet (14). The longitudinal axis (G) of each gas supply nozzle (22) is inclined relative to the longitudinal centre axis (M) in such manner that said axes do not intersect.

Abstract: A simplified process for the partial purification of contaminated phosphoric acid plant pond water having a molar calcium plus magnesium to fluorine ratio greater than or equal to about 0.60, is described, in which the pond water is treated with a basic compound, clarified, aged, clarified again and re-acidified. The thus treated pond water, still containing the majority of the phosphate originally present, can then be concentrated via the removal of essentially pure water, using any conventional means of concentration, without the formation of solid precipitates.

Abstract: Methods for direct reduction of ammonia from waste streams by the steps of reacting an aqueous ammonia containing waste stream with a solution of a strong acid and a metal salt, wherein the cation in said metal salt of said solution is selected from the group consisting of Ag, Cd, Co, Cr, Cu, Hg, Ni, Pd, Zn; and wherein an ammonium-double salt is formed with said metal salt in an ammonia depleted waste stream; and treating said depleted waste stream to crystallize an ammonium-metal double salt therefrom.

Abstract: A process for the partial purification of contaminated phosphoric acid plant pond water is described, in which the pond water is treated sequentially, with two basic compounds, clarified, aged, clarified again and re-acidified. The thus treated pond water, still containing the majority of the phosphate originally present, can then be concentrated via the removal of essentially pure water, using any conventional means of concentration, without the formation of solid precipitates.

Abstract: For purifying an iron(II) salt solution contaminated with nickel ions and lead ions, the hyperstoichiometric addition of sodium sulfide or sodium hydrogen sulfide in the acid range has proved itself as suitable when a residence time in the order of one hour is adhered to before the sulfides are removed by filtration. The residual contents are equal to less than 30 mg per liter for nickel and less than 7.5 mg per liter for lead.

Abstract: Methods for rendering a cyanide or cyanide-containing compound substantially insoluble in an aqueous solution or suspension of cyanide-containing materials comprising: mixing a reagent comprising a thiosulfate salt with said solution or suspension; and adding to said material a complexing agent selected from the group consisting of divalent copper salts, divalent iron salts, divalent cobalt salts, activated carbon and mixtures of the foregoing are provided.

Abstract: A process and apparatus for treating a fluorine-containing waste solution that is able to maintain a high treatment volume while also facilitating easy maintenance. A calcium salt such as calcium hydroxide and an inorganic coagulant are added with timing to the fluorine-containing waste solution, followed by filtration of said waste solution by cross-flow filtration.

Abstract: An animal treatment method comprises flushing the animal waste from a barn to a holding tank where the waste is mixed with an alkaline solution to kill pathogens. After neutralization, the solution is separated into solids and liquids. The liquid is treated and recycled as flushing water to clean the barns and/or drinking water for the animals. The solids are separated into digested and undigested feed. The digested feed is further processed for use as a fertilizer and the undigested feed is processed for use as animal feed.

Abstract: Disclosed herein are chemical methods for reducing concentrations of perchlorate ion in sources of water to be used for potable purposes. The disclosed methods include contacting water containing perchlorate ion with iron metal to chemically reduce the perchlorate ion to a more innocuous ion species. The metal can then be removed. The instant methods also relate to contacting perchlorate contaminated water with iron metal or a metal oxide in the presence of phosphoric acid to form a complex with perchlorate ion and adsorb the complex onto the iron, which is then removed from the water. These methods provide an environmentally safe and economically efficient means to effectively remove perchlorate ion from potable water sources, resulting in water that is safe for human use and consumption.

Abstract: The present invention involves an improved integrated reactor and solids settler system for solids removal from a water stream. The integration of the rapid mix reactor and the solids settler of the present invention uses an overflow line from the rapid mix reactor to eliminate both the rapid mix reactor level indicator and controller and the flow controller in the solids settler clarified water outlet. The proposed design is simple, cost effective, and eliminates the possibility of unnecessary downstream unit shutdowns.

Abstract: A treating method and apparatus for treating a manganese containing water by crystalizing and removing a soluble manganese in a water to be treated containing carbonic acid ions by passing the water to be treated as an upward flow through a fluidized bed reaction tower having no support bed and containing manganese sand as a fluidized bed material and by adjusting a pH value of the water to be treated in said fluidized bed. A suspended manganese is also removed together with said soluble manganese in the water to be treated by forming a suspended solid in the water to be treated into a layer on said manganese sand fluidized bed by removing said layer of suspended solid. Further, a desired quantity of the treated water is introduced into the water to be treated for circulatory use.

Abstract: Fatty oil and acids, glycerol, glycols, lactic acid, urea, fertilizer, carbohydrates, ethanol are recovered or produced from sewer sludge by the process of concentrating and filtering out the solid sewer sludge, hydrolysis of the cellulose in the sewer sludge by an alkali or acid catalyst to carbohydrates, fermentation of the carbohydrates to produce ethanol, then recover the ethanol by distillation or membrane technology. The glycerol, glycols and lactic acids are recovered by membrane technology. The polysacchride carbohydrates are hydrolyzed to monosacchrides then fermented to alcohol. The unsoluble sewer sludge and the salts such as ammonium sulfate, nitrogen containing compounds and urea from the aqueous solution left after the ethanol is distilled off are mixed, dried and utilized as fertilizer.

Abstract: The present invention relates to a method for removing pollutants from aqueous photographic effluent containing silver in completed form and (or) thiosulfates.

Abstract: The process is composed of the following steps: (a) production of the fresh wiping solution, (b) introduction of the fresh wiping solution into one or more wiping tanks, where it is contaminated by the inks. In addition, it comprises the following steps: (c) treatment of the used solution exiting from the wiping tank or tanks with a chemical agent, producing a solution and sedimented ink, (d) separation by settling of the solution obtained in step (c), producing a clean solution and a concentrated solution with sedimented ink, (e) filtration of the concentrated solution, producing a clean solution and solid waste, and (f) use of the clean solution obtained in steps (d) and (e) as fresh wiping solution.

Abstract: A method of treating an animal waste slurry so as to efficiently extract nutrients, and which can be performed in a zero-discharge system, comprises flocculating the slurry, processing, e.g. filtering, the flocculated slurry to separate liquid from solid material, drying the solid material, processing the liquid to extract ammonium, phosphorous and potassium from the slurry, all within 24 hours, and preferably on average within 12 hours, of production of the waste material by animals. Since the urates of potassium and ammonium in the slurry take a few hours to break down, they remain in crystalline form and therefore a larger portion of the total amount of potassium and ammonium in the slurry can be extracted.

Abstract: A batch or continuous process for the removal by flocculation of silicon and heavy metal contamination from aqueous waste streams by the addition of an aluminum salt, particularly, aqueous streams recycled as electrolyte in the electrolytic production of alkali metal or alkaline earth metal chlorates. The process is particularly suited to the removal of heavy metals and silicon contamination in an electrolyte recycled to an electrolytic cell subsequent to the removal by crystallization of a chlorate salt. An aluminum salt, such as aluminum chloride, aluminum chlorohydrate, and polyaluminum chlorides including polyaluminum chloride sulfates is effective as a flocculating agent.

Abstract: Chloride is selectively isolated as NaCl from N-phosphonomethyliminodiacetic acid process wastes by evaporative crystallization of the caustic neutralized brine.

Abstract: The present invention relates to a remover of dissolved fluoride ion for removing fluoride ions contained in wastewater and a treatment method for wastewater containing fluoride using the same. In order to achieve the above objects, the present invention provides a remover of dissolved fluoride ion comprising: a) hydrochloric acid solution reacted with calcium carbonate, and b) a mixture of poly sodium metaphosphate and active aluminum or aqueous solution of mixtures thereof, or an aqueous solution of rare earth element compound, and a treatment method for wastewater containing fluoride using the same.

Abstract: Disclosed is an economical single stage membrane process intended to provide very high overall water recoveries from natural sources or wastewater containing high concentrations of hardness and other inorganic scale-forming compounds while preventing scale formation on the membrane and prolonging the useful life of the membrane. The water is first pre-treated in order to separate all suspended matter using a suitable oil separation device, dissolved air flotation, coagulation, flocculation, clarification, single or multi-media filtration, ultra-filtration, micro-filtration or a suitable combination of these pre-treatment steps. The pre-treated water is then purified using a simple, economical single stage membrane system operating at a suitable pressure depending on the water TDS and desired permeate recovery. In order to prevent scale formation on the membranes, the membrane concentrate is softened using a “low-cost” ion exchange softening resin with high selectivity for hardness precursors.

Abstract: A system and method are disclosed for increasing the concentration of hypochlorous acid in a quantity of water. Acid is injected into chlorinated water to decrease the pH of the chlorinated water. By decreasing the pH, the hypochlorite/hypochlorous acid equilibrium of the chlorinated water is shifted to increase the concentration of hypochlorous acid on the treated water.

Abstract: A method for producing zinc diammine chloride (ZDC) from a solution of zinc ammine sulfate and zinc ammine chloride by precipitating the ZDC by pH neutralization using hydrochloric acid. ZDC can be granulated for dry applications using melt granulation at about 340-360° F. Applications for ZDC include use in fertilizer formulation to provide a combination zinc/nitrogen source free of other metals and use as a galvanizing preflux adjuster. As a galvanizing preflux adjuster, ZDC addition is able to adjust the pH of the preflux while maintaining the desired zinc/ammonia ratio.

Abstract: The present invention relates to a method of defluoridation of waste water, including a step of acid neutralization between a basic neutralization step and a decantation step.

Abstract: An algicide-flocculant solution for use in treating raw water in a municipal water plant to control algae, the algicide-flocculant solution including 25-50 wt % of an acidic flocculant, 0-10 wt % of a polymer flocculant aid, an algicide of essentially copper having a concentration of 0.025-1.25 wt % in the form of a water soluble capper salt, and balance water. Uniform mixing of the flocculant into the raw water simultaneously uniformly mixes the algicide of the algicide-flocculant solution into the raw water. The acidic flocculant is preferably aluminium sulfate, iron sulfate, iron chloride or mixtures thereof. The water soluble copper salt is preferably copper sulfate, copper chloride, copper nitrate, copper acetate or mixtures thereof. Moreover, the flocculant aid is a high molecular weight quaternary amine such as diallyldimethylammonium chloride.

Abstract: A composition for treatment of water and soils comprises components A. CaCO3, B. at least one compound selected from the group consisting of calcium salts, including CaCl2 and Ca(NO3)2, and inorganic magnesium compounds, C. at least one compound selected from the group consisting of NaHCO3 and KHCO3, wherein the components A and B are present in a molar ratio of from 0.1:1 to 1:1, and wherein the components B and C are present in a molar ratio of from 1:3 to 1:1.

Abstract: A water treatment process for raw water containing dissolved Fe2+ and H+ cations to reduce the Fe2+ cation concentration therein involves oxidation of the Fe2cations to Fe3+ cations with the formation in the water of solid Fe(OH)3 from the Fe3+ cations. The process comprises the steps of oxygenating the water and raising the pH of the water. The oxidation of the Fe2+ cations and the fromation of the Fe(OH)3 are carried out in the presence of suspended particulate material in the water, the particulate material being present in the water at a concentration of at least 5 g/l.

Abstract: A process for removing dissolved uranium from water is provided. The process basically comprises (a) mixing phosphoric acid or particulate bone ash with the water, (b) mixing calcium hydroxide with the mixture produced in step (a) to thereby form calcium hydroxy phosphate or calcium hydroxy apatite which reacts with and complexes at least a portion of the uranium in the water to form a precipitate thereof, and (c) separating the precipitate from the water.

Abstract: Small amorphous silica particles are used to provide a relatively large surface area upon which silica will preferentially adsorb, thereby preventing or substantially reducing scaling caused by deposition of silica on evaporative cooling tower components, especially heat exchange surfaces. The silica spheres are contacted by the cooling tower water in a sidestream reactor, then separated using gravity separation, microfiltration, vacuum filtration, or other suitable separation technology. Cooling tower modifications for implementing the invention process have been designed.

Abstract: This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and/or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.

Abstract: The present invention relates to a method of defluoridation of waste water, including a step of acid neutralization between a basic neutralization step and a decantation step.

Abstract: Embodiments of the present invention relate to methods and systems for removal of contaminants from aqueous solutions. The methods and systems of these embodiments are particularly suited to removal of arsenic species as well as transition-metals, post-transition-metals, phosphates and other contaminants in aqueous solutions. The methods and systems of embodiments of the present invention provide for the addition of a reagent to a contaminated solution in combination with a pressurization process and a depressurization process. Contaminant particulates and solids produced in these processes may be removed by conventional separation techniques.

Abstract: A process for utilizing the material of ammonium-containing effluent which contains further soluble constituents and, possible additional solids, comprising: a) optionally separating off the solids, b) concentrating the substantially solids-free ammonium-containing effluent to give an aqueous concentrate having an increased content of ammonium and additional soluble constituents, with simultaneous recovery of substantially ammonium-free pure water, c) precipitating ammonium as magnesium ammonium phosphate from the ammonium-containing aqueous concentrate, and d) separating off precipitated magnesium ammonium phosphate with recovery of substantially ammonium-free residual concentrate which at least partially contains the additional soluble constituents.

Abstract: Improved methods and compositions for decreasing the bioavailability of metals in soil are provided. Broadly, the methods comprise mixing a source of phosphorus and an oxide of manganese with the contaminated soil so as to reduce the metal bioavailability in the soil. The phosphorus source and oxide of manganese can be individually mixed with the soil, or can be provided as a premix powder or granule to be mixed with the contaminated soil. Preferably, the pH of the soil is then adjusted to, and maintained at, a level of at least about 7.0. Preferred phosphorus sources include phosphate rock, alkali and alkaline earth metal phosphates, ammonium phosphates, ammonium orthophosphates, orthophosphoric acid, and superphosphates. Preferred oxides of manganese include MnO2, Mn3O4, birnessite, cryptomelane, and psilomelanes.

Abstract: Wastewater treatment processes and preferred systems for practice of the processes, the invention particularly intends the removal of particulates and dissolved materials contaminating the effluent of garment stonewashing, acid washing and similar processes including chlorinated processes, thereby to allow reuse or sewer discharge of water used in such commercial processes. The processes of the invention typically involve initial filtration to remove solid particulates such as pumice, sand, glass beads and the like followed by acidification of the wastewater and contact with a magnesium hydroxide/activated carbon bed, the activated carbon removing organics such as dyestuffs and the like while the magnesium hydroxide precipitates other dissolved materials for subsequent mechanical removal. After treatment with magnesium hydroxide, parcipitating compounds such as iron sulfate and/or ferric chloride are added to precipitate other inorganic substances and dissolved materials.

Abstract: A method for removing accumulated metals from a cleaning solution is provided. After removal of the metals, the cleaning solution can be discharged or recycled. The process manipulates the pH levels of the solution as a means of precipitating solids. Preferably a dual phase separation at two different pH levels is utilized.

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.