Abstract: A method of treating a wastewater is provided and can be used, for example, to treat a gas well hydrofracture wastewater. The method can involve precipitating barium as barium sulfate, precipitating calcium and strontium as calcium carbonate and strontium carbonate, precipitating magnesium hydroxide, and filtering out the metal compounds to form a recycle water. The recycle water produced from the method is also provided, as is a method for using the recycle water as a gas well hydrofracture water. In some embodiments, discharge water from a coal mine, and/or water from an abandoned coal mine, is used as a source of sulfate ions to precipitate barium as barium sulfate.

Abstract: Treatment of waste water from a biomass-to-liquid process, said process comprising producing synthesis gas from biomass and conversion of said synthesis gas into liquid hydrocarbons by a Fisher-Tropsch process. The waste waters obtained are purified in common with waste waters from another industrial process to which said biomass-to-liquid process is integrated, such as in forestry, power and/or heat generation, waste incineration or a process in a metal-, petrochemical and/or oil refining industry. The biomass-to-liquid. process and said another industrial process may have a common feed water process unit, a common cooling water process unit and a common waste water treatment unit. The waste water treatment process may comprise a biological purification process and said Fischer-Tropsch process may utilize a cobalt catalyst. An integrated factory comprising a biomass-to-liquid plant and another industrial facility in which both plants are connected to a common waste water treatment facility is also described.

Abstract: A wastewater treatment system includes independent wastewater treatment facilities. Each of the facilities has a number of wastewater treatment subsystems. A wastewater collection subsystem holds wastewater to be treated. A pump subsystem moves wastewater from a wastewater collector to a filtration subsystem having a bioreacting filter. The filter has a sump and a fluidized-bed filter therein and supports the filter upright. The filter has an upwardly expanding, hollow, conical filter body with filter media. A monitoring subsystem measures wastewater process parameters. Control devices receive control commands and, dependent upon the command received, alter parameters of the wastewater treatment subsystems.

Abstract: This invention is directed to an integrated process and system for water treatment, in particular, an integrated process and system for water treatment in the beverage manufacture cycle. The water treatment process is directed to treating an influent water solution, a low sugar concentration solution, and a high sugar concentration solution. The water treatment system is directed to a system for treating an influent water solution, a system for treating a low sugar concentration solution, and system for treating a high sugar concentration solution.

Abstract: A method of supporting denitrification includes receiving biological material at a pulsed electric field station and applying a pulsed electric field to the biological material within a treatment zone in the pulse electric field station to generate treated biological material. The method also includes transporting at least a portion of the treated biological material to an anoxic bioreactor in substitution, at least in part, for an external source of electron donor. A system for supporting denitrification is also provided.

Abstract: A method for wet oxidation of organic material, characterized by the utilization of the heat generated by the oxidation of the pollutants that are present in a first preheated wastewater introduced at the base of the reactor in order to provide the energy sufficient to trigger the oxidation reaction in a second wastewater, which is introduced in a higher point with respect to the base of the reactor and has a temperature that is proximate to the ambient temperature and a high concentration of pollutants; and an apparatus adapted to provide this innovative wet oxidation method.

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: The present invention generally relates to a copper metal recovery system, able to integrate with a waste treatment system of a circuit board manufacture plant, includes a stirring unit, a crystallization unit and a pressure filtering unit. More than 2 parts of weight of acidic copper-containing etching process effluent, less than 1 parts of weight of copper-containing slurry, and less than 1 part of weight of waste mixture of an acidic copper-containing photolithography effluent and an acidic frame etching effluent are charged into the stirring unit to conduct decomposition. Alkaline hydroxide reacts with decomposition products in the crystallization unit. The temperature of the crystallization unit is at least 80° C. The pressure filtering unit outputs a copper hydroxide solution or a copper oxide solution.

Abstract: Alkaline waste waters formed in the washing of crude nitrobenzene which has been prepared by the adiabatic nitration of benzene with nitrating acid, washed in an acidic washing process, and then washed in an alkaline washing process are treated. The alkaline waste water being treated generally contains benzene in a concentration of from about 100 to about 3000 ppm and nitrobenzene in a concentration of from about 1000 to about 10,000 ppm. In the process of the present invention, undissolved benzene and/or nitrobenzene are separated from the alkaline waste water, residual benzene and/or nitrobenzene is/are then optionally stripped out of the alkaline waste water, and the alkaline waste water from which benzene and/or nitrobenzene has been removed is heated to a temperature of from 150 to 500° C. under excess pressure with the exclusion of oxygen.

Abstract: A new and improved wastewater treatment system suitable for the treatment of wastewater from a CMP process. A holding tank receives wastewater from a CMP wastewater collection tank. The holding tank may further receive wastewater from a backside grinding (BG) wastewater collection tank. A reaction tank receives wastewater from the holding tank. A coagulant polymer binds to the slurry particles in the reaction tank to precipitate the slurry particles out of solution. One or a pair of clarifiers receives the wastewater from the reaction tank, and the polymer-bound slurry particles are separated from the wastewater in the clarifier or clarifiers. An effluent collection tank receives the purified wastewater from the clarifier or clarifiers. The purified wastewater may be pumped to a storage tank such as a reused city water (RCW) tank for use in scrubber cleaning processes, for example.

Abstract: A device and method for removal of liquid from the downstream side of a membrane or a well, such as a well of a multiwell plate. More specifically, the present invention is directed to a wicking structure, which channels droplets of liquid away from a membrane in communication with a plurality of wells. In the preferred embodiment, the wicking structure is placed in a manifold.

Abstract: A device and method for removal of liquid from the downstream side of a membrane or a well, such as a well of a multiwell plate. More specifically, the present invention is directed to a wicking structure, which channels droplets of liquid away from a membrane in communication with a plurality of wells. In the preferred embodiment, the wicking structure is placed in a manifold.

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 device and method for removal of liquid from the downstream side of a membrane or a well, such as a well of a multiwell plate. More specifically, the present invention is directed to a wicking structure, which channels droplets of liquid away from a membrane in communication with a plurality of wells. In the preferred embodiment, the wicking structure is placed in a manifold.

Abstract: A method and apparatus are disclosed for mixing sewage sludge with spent water-softener lime in a ratio of approximately 10:1 on a wet basis. The mixture is introduced to a rotary pre-dryer kiln and a rotary combuster kiln to kill pathogens. An ash by-product and gases are thereby produced. The ash by-product can be disposed of at much less cost or can be incorporated in a variety of applications such as an aggregate substitute.

Abstract: A method is provided herein for the extraction of phenol from a waste water stream. The method is used in conjunction with a process for producing acetone and phenol from cumene. The method for extracting phenol from waste water includes contacting in a countercurrent mode a phenol-containing waste water stream with a hydrocarbon stream derived from a bottoms stream from the acetone finishing column to produce a dephenolated waste water stream and a phenol-containing hydrocarbon stream. The phenol-containing hydrocarbon stream is preferably washed with an aqueous caustic solution to provide a hydrocarbon stream, which is then conveyed to the alpha-methylstyrene recovery system. Preferably the hydrocarbon stream derived from the bottoms stream of the acetone finishing column is water washed prior to contacting the phenol-containing waste water stream.

Abstract: The present invention is aimed at treating rainwater in a combined sewer system, while enabling removal of a majority of pollution substances even if a large amount of entering rainwater. The invention relates to a rainwater-treating apparatus in a combined sewer system, said apparatus comprising a plurality of upward flow type high-speed filter vessels each having a layer of a floating filter medium, a common treated water vessel which is located at upper faces of said high-speed filter vessels and is adapted to collect treated water from the high-speed filter vessels, a used wash water vessel which collects used wash water from said high-speed filter vessels, a rainwater inflow channel for distributing the entering rainwater into upper portions of the high speed filter vessels, and rainwater inflow portions for flowing downwardly the rainwater distributed from the rainwater inflow channel under the respective floating filter media of the filter vessels.

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: An apparatus for treatment of fluorine waste water has an introduction tank, a main treatment tank, a calcium hydroxide tank, a polychlorinated aluminum tank, a macromolecular flocculant tank, a settling tank, and a concentration tank. Fluorine waste water is introduced through the introduction tank into a lower part of the main treatment tank through a lower inlet pipe. Also, return sludge from the concentration tank and silicon sludge from a silicon waste water treatment system are introduced into an upper part of the main treatment tank. Thus, silicon recovered from silicon waste water is recycled for treatment of fluorine waste water. Also, unreacted chemicals, which have been loaded in the calcium hydroxide tank, polychlorinated aluminum tank, macromolecular flocculant tank, are recycled. The main treatment tank has no stirrer, and thus conserves electrical energy, but can neutralize the waste water.

Abstract: A source of sewage is coupled to a septic tank by an influent line. The outlet line is coupled to a sewage treatment plant by an outlet line. Sewage travels from the source to the septic tank where solid matter is filtered. Liquid matter passes through the septic tank into the outlet line where it transported to the sewage treatment plant to be treated. The outlet line may consist of an indefinite number of intermediary lines and valves, such as an effluent line adjacent to the septic tank, a distribution line adjacent to the sewage treatment plant, and a valve disposed in between the effluent line and the distribution line. The valve may be coupled to a leach field so that liquid matter traveling from the effluent line to the valve may be directed either to the leach field or the distribution line leading to the sewage treatment plant.

Abstract: An apparatus for treatment of fluorine waste water has an introduction tank, a main treatment tank, a calcium hydroxide tank, a polychlorinated aluminum tank, a macromolecular flocculant tank, a settling tank, and a concentration tank. Fluorine waste water is introduced from the introduction tank into a lower part of the main treatment tank through a lower inlet pipe. Also, return sludge from the concentration tank and silicon sludge from a silicon waste water treatment system are introduced into an upper part of the main treatment tank. Thus, silicon recovered from silicon waste water is recycled for treatment of fluorine waste water. Also, unreacted chemicals, which have been loaded in the calcium hydroxide tank, polychlorinated aluminum tank, macromolecular flocculant tank, are recycled. The main treatment tank has no stirrer and thus conserves electrical energy, but can still neutralize the waste water.

Abstract: Process for the treatment of polluted metal-mechanic industrial waste water and urban water, comprising: treating the polluted water with an acid liquor including ferrous chloride and hydrochloric acid, in order to promote the denaturalization of protein present in metal-mechanic industrial water or urban water and generate a clarifying and purifying flocculus from said polluted water.

Abstract: A process for reducing the loading of wastewaters produced in the preparation of hydroxyl and carbonyl compounds from hydroperoxides by the Hock process, which may be acidic, by treating the wastewaters with an oxygen-containing gas at a pressure greater than 25 bar absolute and at a temperature of 150-250° C. Surprisingly, improved degradation rates are achieved under these conditions.

Abstract: Silver recovery from a silver-bearing spent photographic solution is achieved by reducing the silver ions to silver metal with an organic reducing agent, especially a photographic developer reagent; in particular a spent photographic developer solution provides a convenient source of reducing agent for the silver recovery; in this case the developer reagents which typically are phenol-type compounds are oxidized leading to a less toxic discharge effluent having a lower COD and BOD.

Abstract: A process for treating alkaline solutions obtained from lithographic printing plate processing comprises admixing at least one alkaline solution and at least one acidic solution in the presence of at least one aqueous solution to obtain a discharge solution having a pH in the range of about 5.0 to 11.5. Another process for treating alkaline solutions obtained from lithographic printing plate processing comprises admixing at least one alkaline solution and at least one aqueous waste water solution to obtain an aqueous alkaline solution, and admixing the resultant aqueous alkaline solution with at least one acidic solution to obtain a discharge solution having a pH in the range of about 5.0 to 11.5, and to control systems for such processes, and methods of controlling such processes. The alkaline solution has a pH greater than 7.0, preferably greater than about 12.5, and the acidic solution has a pH less than 7.0, preferably less than about 2.5.

Abstract: The invention concerns an optimized method for the treatment and energetic upgrading of urban and industrial sewage sludge. It consists of a <<novel>> combination of known and tested equipment, forming a compact assembly with six functions which are: anaerobic sludge digestion (1) and biogas production, mechanical dehydration (2) up to 22-24% of dry solid, a gas turbine installation (3) burning the biogas into <<total energy>>, thermal drying (4) of the sludge up to 92% of dry solid consisting of a thin-layer dryer and a vibrated dryer/cooler with fluid bed (4b), condensation of the vapors (5) for heating the digester and the premises, and optimized energetic upgrading (6) of the dried sludge as booster fuel capable of being stored and fed into the household refuse incinerating boiler-furnaces. The method according to the invention is also applicable to the treatment and transformation of liquid manure into granulated and bagged fertilizer.

Abstract: Apparatus and method for accommodating and handling excess deliveries of combined sewage overflows to a sewage treatment plant supported and contained within an offshore moored vessel or platform, by diverting the excess deliveries to ballast tanks for temporary displacement of clean ballast water and to be returned to the treatment system when excess deliveries of combined sewage overflow are relieved. Fluids contained within the ballast tanks are utilized to provide buoyant support for process tankage. Baffles within the ballast tanks minimize undesirable mixing of the combined sewage overflows with the resident clean ballast water.

Abstract: A materials treatment system which initially separates liquid and solid components with a separator. The system can be advantageously utilized for household sewage handling, however various components have other applications. Once the separator separates the solids and liquids, a fire tube combusts the solids with microwaves. The liquids exiting the separator are treated in a liquid treatment system which includes additional particle filtration/separation, treatment of the liquids with an oxidant liquid, and an ultraviolet treatment. An advantageous microwave cavity assembly is also provided for dehydration/combustion of solids exiting the separator and/or for solids filtered from liquids in the liquid treatment system.

Abstract: A sludge, preferably derived at least in part from a paper mill, pulp mill or deinking plant, and which contains at least secondary sludge or primary sludge comprising deinking waste, recycled paper waste or mechanical pulping waste, is flocculated by being mixed with a phenolic material and a polyalkylene oxide and is then subjected to dewatering.

Abstract: A method of manufacturing a water treatment system for providing a flow of treated water having a pre-established quality, for example, a maximum TDS and permitted pH range, from a flow of reclaimed water having a quality poorer than the pre-established quality of the treated water and a flow of treatment water. The system includes a mixing reservoir; first and second fluid conduits connected to the mixing reservoir for flowing the reclaimed water and the treatment water into the reservoir; and a third fluid conduit connected to the mixing reservoir for discharging a flow of treated water from the mixing reservoir, and sensors connected for sensing the flow rates and qualities of the reclaimed water and treatment water flowed into the mixing reservoir and of the treated water discharged from the mixing reservoir. Signals, e.g.

Abstract: A method for accelerating the treatment of chemical wastes, particularly recalcitrant wastes such as spent caustic, from the oil, gas, chemical, and petrochemical industries, in which normally slow physical mass transfer of different fluid phases, as well as other chemical reactions, are facilitated. The method involves mixing together the different fluid phases and delivering the mixture to a reaction vessel in the form of an aerosol and froth which provides a large surface area between the phases. The aerosol and froth mixture is maintained and replenished for a period of time sufficient to effect mass transfer and stripping of the contaminants to a selected level of completion. The method enables the provision of more environmentally acceptable wastes for disposal.

Abstract: A waste containing organic solids is fed into a boiler after it has been subjected to a hydrothermal reaction treatment in the presence of water. A slurry containing the waste is held under high-temperature and high-pressure conditions to cause a hydrothermal reaction such that an acidic slurry is formed during part of or throughout the process of the hydrothermal reaction. Thereby the content of oxygen in the waste relative to carbon atoms in building molecules of the waste is reduced. This concurrently causes removal of halogens in said building molecule and transferring the halogens into the slurry. The slurry then is cooled and dewatered and fed into a combustion section of the boiler. The waste slurry to be subjected to the hydrothermal reaction can be sorted into two portions for separate storage. One portion is a waste slurry the pH of which will increase as a result of the hydrothermal reaction. The other portion is a waste slurry the pH of which will decrease during the hydrothermal reaction.

Abstract: Water to be utilized is reacted with soda ash and lime to produce a less corrosive and foulant water. Reaction sludges are fed to a desulfurization unit, where SO.sub.x, NO.sub.x and CO.sub.2 abatement occurs; other industrial waste sludges and/or waters and/or gases can also be utilized in such connection. FIG. 1 is one of the possible process schemes of present invention.

Abstract: A method for the treatment of waste water, which comprises treating waste water containing at least a sulfide-type malodorous substance, in the presence of a transition metal compound and hydrogen peroxide or a hydrogen peroxide-forming compound, wherein at least an iron family element compound and a vanadium family element compound are used as the transition metal compound.

Abstract: Water to be utilized is reacted with soda ash and lime to produce a less corrosive and foulant water. Reaction sludges are fed to a desulfurization unit, where SO.sub.x, NO.sub.x and CO.sub.2 abatement occurs; other industrial waste sludges and/or waters and/or gases can also be utilized in such connection. FIG. 1 is one of the possible process schemes of the present invention.

Abstract: A method and apparatus facilitate removal of metals from acidic liquids containing dissolved metals (such as pulp mill bleach plant washer filtrate) by oxidizing the liquid with ozone, hydrogen peroxide, oxygen, and/or air to increase the valence of the metals (like Mn and Fe) so that they become easier to precipitate. Oxidation may be practiced using any suitable reactor, such as a gas-contact reactor, or a plunger type reactor where the oxidizing agent is primarily gaseous, or a static mixer or stirred tank where the oxidizing agent is primarily liquid. After oxidation the pH of the liquid is adjusted (e.g. to over 6, preferably about 8-11) to precipitate the metals. The precipitated metals are then removed by filtration, sedimentation or flotation, and the metals-depleted liquid used elsewhere in the pulp mill.

Abstract: There is provided a hydrogen peroxide removal equipment which has a high capability for removing hydrogen peroxide and is able to cope with variation in amount of a hydrogen peroxide containing waste water and variation of a hydrogen peroxide concentration occurring in a semiconductor plant. A tank 51 is internally provided with a first decomposition section 16, a second decomposition section 17 and a third decomposition section 8 which are constituted by combining a charcoal 9 and a plastic material 10 having a void capable of allowing water and gas to pass therethrough. The first and second decomposition sections 16 and 17 are provided below the level of an outlet port 42 and arranged on both sides of a vertical partition plate 13 located apart from a bottom plate 51E. The third decomposition section 8 is provided above the level of the outlet port 42 and arranged above the first and second decomposition sections 16 and 17.

Abstract: The present invention is directed to the use of water-soluble compositions containing a compound having a Lewis base group attached to a hydrophobic group where the Lewis base group is capable of donating at least one lone pair of electrons to a metal. These compositions are effective in treating acid mine drainage by treating the source of the acid mine drainage as well as the acid mine drainage waters. These compositions are also effective in removing metal and non-metal ions from aqueous sources and the process can be modified to allow the selective removal of metal and non-metal ions from aqueous sources.

Abstract: A sewage purification method which includes a first step in which at least two kinds of flocculants are introduced in sewage for stirring and mixing therewith so as to float and settle inorganic and organic materials. The first step is sequentially repeated more than one time. Next, at least three kinds of flocculants are introduced into the supernatant obtained in the first step for stirring and mixing therewith so as to further float and settle remaining inorganic and organic materials. At least one of the first and second steps is sequentially repeated more than one time. In the above way, middle water, drinking water and super-pure water can be obtained from sewage. Purification of exhaust gas is also possible by introducing such exhaust gas in one of the above steps.

Abstract: Processes are provided for the thermophilic digestion (55.degree. C. to 65.degree. C.) of chitinous wastes to produce a solubilized form of chitin that may be applied to plants to stimulate their resistance to disease and attack by insects and fungi. Also provided are processes for treating a combined waste, including a waste containing chitin and an organic waste, to produce a substantially human and plant pathogen-fee product that may be used not only to stimulate plant resistance, but also to act as a fertilizer. The thermophilic digestion processes may be carried out with ubiquitous organisms, under at least marginally aerobic conditions, and preferably at a near-neutral pH.

Abstract: Potassium permanganate is added to paper mill wastewater streams at an elevated temperature to remove color compounds from the effluent streams. The potassium permanganate causes the formation of flocculant particles which are precipitated out of the stream. This precipitate is then treated with acid to cause resolubilization.

Abstract: The removal of bleaching chemical-consuming metals from treatment fluids in a cellulose pulp mill is facilitated by treating the pulp in an acidic or neutral stage to dissolve metals, washing or thickening the pulp to produce a filtrate containing dissolved metals, and then using an alkali liquid to adjust the pH of the filtrate to cause dissolved metals to precipitate. The alkali liquid is pretreated with carbon dioxide to reduce the sulfide content and increase the carbonate content thereof, preferred alkali liquids being green liquor and white liquor. The reduced-metal content filtrate is used in the bleach plant of the pulp mill, to make bleaching chemicals, as a wash liquid, etc. Treatment of the alkali liquid with carbon dioxide is typically practiced by scrubbing the liquor with carbon dioxide gas, for example, using a plate column scrubber or a stationary packing scrubber.

Abstract: A method for treating waste water which contains organic and inorganic compounds, particularly waste water from the synthesis of epichlorohydrins, in which the waste water is subjected toa) thermal-alkaline treatment,b) biological treatment, andc) optionally to chemical-oxidative treatment.

Abstract: Additives are usually diluted before they are added to a geothermal brine processing stream. It has been found that one preferred diluent is the conditioned steam condensate produced after power generation in the geothermal plants. One class of additives beneficially diluted by the conditioned steam condensate are crystal structure modifiers. When it is diluted with the steam condensate, the heat-sensitive crystal structure modifier is prevented from being degraded by the heat of the brine so that when blended with the geothermal brine the crystal structure modifier can perform its function of inhibiting the precipitation of alkaline earth salts.

Abstract: A method for collecting and treating small particulate pollutants typically found on the surface of streets in areas where the storm sewer and sanitary sewer are maintained separately. The method includes temporarily isolating a portion of the storm sewer in the immediate vicinity of the street to prevent any collected runoff from passing into the storm sewer, and then flushing the street with a stream of water to remove and collect the solid pollutants from the street surface. The flushing water containing the removed solid pollutants is collected and contained in the isolated storm sewer portion, and is then pumped into the sanitary sewer system for treatment in existing sewage treatment facilities.

Abstract: An effluent precipitation and neutralization chamber for mixing and neutralizing spent photographic developer and fixer. The fixer inlet discharging into a vertically oriented conduit located within the vessel, which contains iron therein and defines a gravity flow path for flow of the fixer within the vessel from the inlet to the bottom of the vessel. A layer of steel wool is positioned on the bottom of the vessel in the flow path of the fixer. Baffles inside the chamber promote mixing of the developer and fixer. The desilvered fluid is diluted with wash water before it is discharged from the chamber. A wash water inlet tube is aligned with an open ended vessel that surrounds the discharge outlet to dilute the mixed and neutralized developer and fixer.

Abstract: A process is for removal of suspended solids including resin and fatty acids from pulp mill effluents including Chemi-Thermo-Mechanical Pulp (CTMP) mill effluents. The process involves filtration of untreated or primary treated effluents through a mat of primary sludge, pulp or woodroom sludge. A sludge mat is formed on a wire screen or punched drum and the effluent to be treated is filtered through the mat. Most of the suspended solids and a part of colloidal material and dissolved solids are retained by the mat. Following the filtration stage, the sludge is dewatered and removed. A portion of the sludge is recycled to form the mat for the next filtration cycle, while the excess sludge is purged. The filtration is achieved by the application of vacuum below the filter mat or pressure over mat.

Abstract: A method for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream.

Abstract: An effluent precipitation and neutralization chamber for mixing and neutralizing spent photographic developer and fixer. A baffle and long folded ribbons inside the chamber promote mixing of the developer and fixer. A source of iron ions such as fine steel wool is immersed in the fluids. Ion exchange between the steel wool and the photographic fixer recovers silver from the fixer. The desilvered fluid is diluted with wash water before it is discharged from the chamber. A wash water inlet tube is directly aligned with the discharge outlet opening in the chamber so that wash water can flow almost directly into the outlet tube to dilute the mixed and neutralized developer and fixer.

Abstract: The present invention relates to a method of completely recovering nickel and zinc metal from multiple plating process waste streams by first separating the waste streams into a clean, relatively constant flow and/or concentration fraction and a dirty, variable flow and/or concentration fraction. Metal is recovered from the clean fraction by ion-exchange so as to concentrate the extracted metals for direct return to the plating bath. The effluent from the ion-exchange step is then blended with the dirty, variable flow and concentration fraction. This blended flow is first neutralized and then precipitated in a two-stage process using a sodium hydroxide solution. The resultant slurry containing the metal precipitate is filtered to yield a filter cake containing recovered nickel and zinc. This filter cake can then be further processed to recover the metal for reintroduction into the plating bath or for other uses.