Abstract: This invention is directed to a method and apparatus for controlling and optimizing the feed of two or more oxidizers to an aqueous stream, thereby providing a synergistic effect. The system combines the use of amperometric or ORP based sensor technology with amperometric sensor technology employing a gas permeable membrane, thereby providing definitive control of each oxidizer feed stream.

Abstract: A waste stream from energetics processing is treated using a pre-filter having media, preferably sand, and a metal that has a reducing potential, preferably elemental iron (Fe0). The pre-filter is connected to a zero-valent metal column reactor. The waste stream is pumped through the pre-filter to trap solids and deoxygenate it, then enters the reactor and is subjected to a reducing process. Most of the Fe0 is transformed to the ferrous ion (Fe+2), added to the resultant product, and fed to a continuous stirred tank reactor (CSTR) in which Fenton oxidation occurs. This product is then sent to a sedimentation tank and pH-neutralized using a strong base such as sodium hydroxide (NaOH). The aqueous portion is drawn off and the sludge pumped from the sedimentation tank. Both tanks are monitored and controlled to optimize required additives, while monitoring of pressure drop across the pre-filter and column reactor establishes replacement requirements.

Abstract: A method of treating industrial wastewater using casein includes an optimization step whereby treatment operating variable are optimized through statistical methods on experimental designs.

Abstract: A water treatment system and method reduce the pH level of a waste stream from an unacceptably high level with maximum efficiency and safety, and minimum costs and labor. The system includes a pH control system that detects a pH level of the waste stream. An acid discharge unit including a source of acid and an acid feeding mechanism is activated and deactivated by the pH control system according to the pH level of the waste stream. A housing contains the acid discharge unit and at least part of the pH control system. The acid feeding mechanism may feed dry acid directly to the waste stream or premix the dry acid with water to form a wet acidic solution that is fed into the waste stream. A mixing tank may be provided downstream of the housing to serve as an area for mixing acidic materials from the acid discharge unit with the waste stream prior to discharge from the plant.

Abstract: The method, in which the water to be treated is partly oxygenated by a specific aeration carried out before percolation through a biofilter having a bacteria-supporting bed of filtering material, has a measurement stage of at least one parameter constituted by the oxidation-reduction potential of the aerated water before passage into the biofilter, a transmission stage of measurement signals to a computer and comparison of the signal representative of the value of the measured parameter with at least one lower limit set in function of the measurement carried out in a second stage for measuring a parameter representative of the pH and a stage for correcting the air flow by a signal determined by the computer in function of the two preceding stages.

Abstract: A method for incubation of nitrifying bacteria in a high concentration which are contained in small amount in activated sludge includes subjecting the activated sludge to nitrification and acclimation culture for about one to two months using a sludge-treated waste liquid such as dehydrate sludge filtrate and digested eluate under such a condition that the dissolved oxygen is 2-4 mg/liter, the pH is 7.5-8.5 and the temperature is 25-35° C. and, at the same time, constantly maintaining the pH within the pH range of 7.7-8.5 by addition of an incubation promoter comprising a mixture of sodium carbonate and sodium hydrogen carbonate.

Abstract: In a circulation system of treatment-object water (waste water), a water treating apparatus and a pH adjuster are provided. A carbon fiber that can collect at least microorganisms is disposed in the water treating apparatus. The carbon fiber is immersed in the treatment-object water, and potential is applied to the carbon fiber. Further, pH of the treatment-object water is adjusted by the pH adjuster in a direction in which adsorption of microorganisms in the treatment-object water to the carbon fiber is facilitated. As a result, the microorganisms are strongly attracted and adsorbed to the carbon fiber.

Abstract: In the invention, the pipe lines around permselective membranes and the surfaces of permselective membranes are intermittently disinfected by adding an inexpensive acid such as sulfuric acid or the like to pre-treated crude water so as to make the water have a pH of 4 or lower. Accordingly, the invention provides a method of surely disinfecting the permselective membranes in membrane separation systems.

Abstract: A cooling tower water purification system uses an electrical cleaning method by passing water over or through an anode and a cathode. The pH of the water is monitored and adjusted using injected CO2 gas. The water can also be mechanically filter to remove the now dead biofilm and biomass as well as any scale or other debris. An additional embodiment can use an additional device such as a water jet to “stir” the bottom of the cooling tower to increase the efficiency of the filter in removing any built up or remaining biomass, scale or the like.

Abstract: An insecticide delivery apparatus may include an insecticide extraction chamber having an outlet adjacent a lower end thereof, and a screen adjacent the outlet for holding a mass of insecticide bearing bodies to partially fill the insecticide extraction chamber. A nozzle may be positioned adjacent an upper end of the insecticide extraction chamber for directing a water stream downwardly therefrom toward the mass of insecticide bearing bodies. An air control device may control the water level and associated head space so that the insecticide bearing bodies are at least partially submerged in the water. The bodies may be churned in the water by action of the stream to enhance delivery of insecticide into the water. The apparatus may provide efficient and cost effective control of a number of insects, such as midge flies, that are prevalent in a trickling filter of a typical wastewater treatment plant.

Abstract: A method for determining the quantity of phenol extracted into an aqueous solution of an alkali metal hydroxide uses a measurement of the pH of the solution, from which the equivalents of phenol relative to alkali metal hydroxide in solution is determined. A method for optimizing the use of an aqueous solution of an alkali metal hydroxide in a phenol recovery process uses pH measured to regulate the feed rate of the aqueous solution.

Abstract: Abrasive components and clear fluids are separated from an aqueous chemical mechanical slurry used for planarization of semiconductor materials, to permit the reuse of the clear liquid effluent in non-process applications as well as for gray water for irrigation, process cooling water, or as make-up water for a reverse osmosis system, or safe disposal in the industrial waste stream, as desired. A solids detection device determines the concentration of abrasive solids in the aqueous waste effluent stream, and a diverter valve receives and diverts the entire aqueous waste effluent stream to at least one reuse water collection tank when the abrasive solids concentration is below a desired threshold, and diverts the entire aqueous waste effluent stream to at least one concentrate water collection tank when the abrasive solids concentration is greater than or equal to the threshold. With the additional use of ion exchange, the resulting water stream can be reused in high purity water applications.

Abstract: A process for producing improved alkaline water includes filtering potable source water to remove selected particles and then purifying the filtered water. Selected alkaline minerals are added to the purified water, with the resulting mineralized water being then electrolyzed to produce streams of acidic water and alkaline water, the alkaline water having a pH within the range of 9-10, a TDS range of 22-240 ppm (parts per million) and alkalinity in the range of 12-216 ppm.

Abstract: This invention is directed to a method and apparatus for controlling and optimizing the feed of two or more oxidizers to an aqueous stream, thereby providing a synergistic effect. The system combines the use of amperometric or ORP based sensor technology with amperometric sensor technology employing a gas permeable membrane, thereby providing definitive control of each oxidizer feed stream.

Abstract: Methods for treating manure treatment systems in confined animal feeding operations to maintain the agricultural equipment, alleys and lagoons in a safer and more effective and useable condition though the use of a sulfuric acid composition. Sulfuric acid mixed with urea is controllably released from a storage tank, through an injection pump and into the fluid line transporting recirculation water from the lagoon to flush livestock alleys with the composition and maintain the pH of the lagoon fluid at approximately 6.5 to 7.0. The composition can also be placed into the fluid line transporting flush water from the livestock alleys to clean the manure separator. The composition can also be sprayed onto the manure separator screens to clean the screens. The composition can be placed directly onto the floor of the concrete alley and allowed to soak thereon to remove accumulated manure, algae and other materials.

Abstract: A system for removing fluoride from wastewater is provided. The system comprises a reaction tank for processing said wastewater by adding calcium salts, a filtration tank for removing the precipitated fluoride formed in the reaction tank, a single fluoride electrode disposed at the reaction tank for measuring a concentration of fluoride in the influent wastewater and providing an output signal, and a programmable controller for controlling addition of said calcium salts into said reaction tank. The programmable controller defines a setpoint of fluoride concentration in the reaction tank and automatically controls addition of calcium salts based on the setpoint and the output signal provided by the single fluoride electrode. A method of removing fluoride from wastewater is also provided.

Abstract: A method of treating industrial wastewater using casein includes an optimization step whereby treatment operating variable are optimized through statistical methods on experimental designs.

Abstract: A process for optimizing the rate of oxidation using halogen, e.g. chlorine donors to prevent the accumulation of undesirable chlorinated by-products. The feed rate of a chlorine donor is controlled for maintaining a desired ORP. The amount of free halogen is reduced and the ORP range expanded by addition of an effective amount of a coagulating agent. The rate of oxidation is sufficient to prevent the accumulation of the undesirable by-products. Treatment removes the by-products from the water and surrounding air by maintaining continuous breakpoint halogenation conditions.

Abstract: A process for optimizing the rate of oxidation using a combination of halogen, e.g. chlorine donors and peroxygen, e.g. potassium monopersulfate. The peroxygen compound elevates the oxidation-reduction potential of the body of water being treated. Simultaneously, a halogen donor is added to the body of water to maintain a PPM level of free halogen sufficient to insure sanitization. The amount of free halogen is reduced and the ORP effective range expanded to 700-850 mv by addition of an effective amount of a coagulating agent. The feed rates and concentrations of both oxidizers are optimized so as to achieve and maintain the targeted parameters. A high level of oxidation is maintained which removes by-products from the water and surrounding air.

Abstract: An agricultural lagoon and manure treatment system to maintain the lagoon and lagoon water in a more useable condition through the use of sulfuric acid to treat the system components of confined animal feeding operations, including the lagoon. Relatively pure sulfuric acid is controllably released from a storage tank, through an injection pump and into the fluid line transporting recirculation water from the lagoon to flush livestock alleys and maintain the pH of the lagoon fluid at approximately 6.5 to 7.0. A sulfuric acid injection pump injects the sulfuric acid into the fluid line through a fluid injector at a rate necessary to maintain the lagoon fluid in the desired pH range. The fluid injector injects the acid at or near the center of the water stream in the fluid line. The rate of sulfuric acid injected is determined by checking the pH of the water downstream of the injection point, such as at the flush alleys, with a hand-held, portable pH meter.

Abstract: A process is described for dewatering sewage sludge consisting of the combination of an acidic oxidative preconditioning with an inorganic post-conditioning, in which case the preconditioning comprises an acidification of the sewage sludge and a catalytic partial oxidation by addition of a substoichiometric amount of hydrogen peroxide and iron ions at a pH≦5 and then an inorganic post-conditioning is carried out in which the acidified and partially oxidized sewage sludge is admixed with alkaline earth, and in which case, in the inorganic post-conditioning, sufficient calcium hydroxide (Ca(OH)2) is supplied so that the pH of the limed sewage sludge is in the range from at least 9 to at most 11, in order thereafter to dewater the conditioned sewage sludge mechanically.

Abstract: A process is provided to create a treated recycle stream through pre-treatment and solids separation for reuse in animal feeding operations without odors and creates a treated liquid effluent that can be stored for reuse, or can be land applied without odors and is free from pathogens and nutrients. Additionally the methods describe a means of converting animal manure to organic fertilizer and removing nutrients from the liquids to create a feed supplement from biomass. The organic fertilizer is non-leaching and free from pathogens. The entire process is accomplished in a reduced footprint from other treatment processes and allows waste ponds to be removed from service.

Abstract: This invention relates to a method and an apparatus for reduction of flow resistance in pipes and ducts where a fluid or a powder is flowing in single or multiphase. In the method, the flow resistance is reduced by applying an electrical field on the pipe or duct wall. Also, the strength of the field is regulated according to measurements of the flow regime before and after the unit which exposes the fluid or powder to the electrical field. The fluid may be a pure fluid, colloidal fluid or contain inclusions in the form of particles.

Abstract: An adjustable continuous filtration system; a continuous split-stream bypass filtration system; a method for controlling the proportion of a fluid recycled through a filtration system; a method for controlling the proportion of a fluid which is routed to the filter of a filtration system, and the proportion of the fluid which is discharged from the system without passing through the filter; and a method for controlling the quality of cooking fats and cooking oils. The mechanisms for controlling the proportion of fluid routed or recycled to a filter depend on the size or width of orifices in passageways conveying the fluid, including the restriction of one or more of the orifices. A needle valve beneficially provides a continuous range of variation of orifice size. If the quality of cooking fat or cooking oil discharged from the filtration system is below industry standards, the proportion of the cooking fat or cooking oil routed or recycled to the filter is increased.

Abstract: Oxygen scavenging with sulfites in boilerwater systems is dependant upon variable interrelated opposing kinetic relationships of ph, transitional catalyst properties and the ratio of bisulfite specie and sulfite specie that will vary between ph 4.5 and 9.0. The sulfite specie, SOsub.3, is formed as the preferential reactant with oxygen, FIG. 2. The oxygen sulfite reaction is second order with respect to sulfite concentrations within boilers. The sulfite specie is 100% favored at ph 8.5 to 9.0. Cobalt is a transitional catalyst that affects an oxygen sulfite reaction directly proportionally to the square root of cobalt's solution concentration but it precipitates at or above ph 8.5, or is complexed in boilerwater by chelants, or is inhibited in boilerwater by amines, or precipitated as its hydroxide by boilerwater alkalinity. Under prior art, these adverse conditions affecting the catalytic activity of cobalt or other metal ions have not been addressed.

Abstract: A reverse osmosis treatment of feed water containing at least silica and hardness ions for separating the feed water into permeate water and concentrate is effected while maintaining the pH of the concentrate at a level of at most 6. According to the foregoing process, silica can be prevented from precipitating, and a high recovery of permeate water can be secured.

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: A process is disclosed for producing an oxidized liquid effluent containing minimal dissolved gases therein, from a subcritical wet oxidation treatment system. The oxidation mixture exiting from the treatment system is separated into a first oxidized liquid effluent and a first gaseous phase as the mixture a first separator vessel operated at a relatively low superatmospheric pressure. Sufficient pressure is maintained in the first gaseous phase to provide the motive force for transport to further treatment or discharge. The first oxidized liquid effluent flows to a second separator vessel operated at essentially atmospheric pressure, where remaining dissolved gases separate from the first oxidized liquid effluent. The second gaseous phase is discharged and the second oxidized liquid effluent is suitable for storage or further treatment. Provision for adjusting the pH of the oxidized liquid effluent during the separation process is also disclosed.

Abstract: A process for optimizing the rate of oxidation using a combination of halogen, e.g. chlorine donors and peroxygen, e.g. potassium monopersulfate. The peroxygen compound elevates the oxidation-reduction potential of the body of water being treated. Simultaneously, a halogen donor is added to the body of water to maintain a PPM level of free halogen sufficient to insure sanitization. The feed rates and concentrations of both oxidizers are optimized so as to achieve and maintain the targeted parameters. A high level of oxidation is maintained which removes by-products from the water and surrounding air.

Abstract: Carboxylic acids are recovered from a fermentation broth by adjusting the pH of a fermentation broth comprised of a carboxylic acid to at least about 6.0 and then heating the pH-adjusted broth to a temperature sufficient to effect the formation of three immiscible phases, one of which is an oily phase rich in the carboxylic acid.

Abstract: A process for optimizing the rate of oxidation using halogen, e.g. chlorine donors to prevent the accumulation of undesirable chlorinated by-products. The feed rate of a chlorine donor is controlled for maintaining a desired ORP, the rate of oxidation is sufficient to prevent the accumulation of the undesirable by-products. Treatment removes the by-products from the water and surrounding air by maintaining continuous breakpoint halogenation conditions.

Abstract: A system for treating contaminated media is provided. In the process, contaminants are removed from the media using a photocatalytic process operating in an aqueous phase.

Abstract: A method and apparatus for treating a liquid (2) to inhibit growth of living organisms therein by adding to the liquid an active biocidal ingredient formed by mixing an oxidant (4) and an amine source (6), by: producing a predetermined dilution of the oxidant (4); producing a predetermined dilution of the amine source (6); synchronously metering the two dilutions into a conduit (16) to continuously mix therein according to a predetermined ratio to produce the active biocidal ingredient having high reproducibility, stability and efficacy in situ in the conduit (16); and continuously injecting the active biocidal ingredient, as it is produced in situ in the conduit (16), directly from the conduit into the liquid being treated.

Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.

Abstract: A system and method for providing an oxidized liquid effluent stream substantially free of volatile compounds is provided. The system includes a stripper positioned downstream of a separator, or disposed within a separator. The method involves volatilizing volatile compounds by performing a separation followed by stripping, or in the same chamber as the separation. In another aspect, the invention involves adjusting the pH of the oxidized waste stream prior to stripping in order to convert ionic species to volatile species that can be removed by stripping.

Abstract: Automated process, conditioning and treatment apparatus and methods are disclosed that are particularly well adapted for closed loop systems using or producing aqueous effluence with varying amounts of suspended solids therein, the apparatus and methods directed to separation of the solids from the effluence and thus cleaning of the centrate. The apparatus includes a mass flow rate meter, liquid polymer injector and control means for receiving the monitored rate from the meter and performing analysis to optimize the rate of injection of liquid polymer. The injector is monitored to further optimize the injection rate.

Abstract: A slurry recycling system for a CMP apparatus includes a flow path through which a slurry used in the CMP apparatus flows. A first filter is disposed in the flow path for filtering out foreign matter of a particle size of more than 0.5 microns mixed in said slurry. A second filter is preferably disposed in the flow path at a location upstream of and away from the first filter for filtering out foreign matter of a particle size of more than 10 microns mixed in said slurry. Preferably, provisions are made for a concentration adjuster for adjusting the concentration of abrasives in said slurry to substantially an initial value before use, and a pH adjuster for adjusting the pH of said slurry to substantially an initial pH value before use.

Abstract: A process and device for treatment of water circulating in a conduit, which water carries microorganisms that must be eliminated and ions susceptible of leading to the formation of deposits on the internal wall of the conduit. To this end, there is injected in the water to be treated effective quantities of ozone and carbon dioxide. Particularly useful to treat the water conduits of a hospital building.

Abstract: A waste processing method decomposing an organic substance or an inorganic substance contained in organic wastes or inorganic wastes by holding a mixture of the organic wastes or the inorganic wastes and a medium, which is in its supercritical state, for a pre-determined time period, in which the hydrogen ion concentration of the medium is 10.sup.-4 mol or more to 1 kg of the medium.A waste processing method having a step of decomposing all or almost all of an organic substance included in organic wastes into lower-molecular-weight products by holding the organic wastes in a medium, which is in its supercritical state, for a pre-determined time and a step of oxidizing and decomposing the lower-molecular-weight products into carbon dioxide (CO.sub.2) and/or water (H.sub.2 O) by holding a mixture of an oxidant and the lower-molecular-weight products in the medium, which is in its subcritical state, for a pre-determined time period.

Abstract: A water system for supplying chilled water to a food production line. The chilled water is held in a holding tank which is sampled by a pump which delivers water to an analyzer. The water is first filtered to remove debris that would hamper the analysis. The analyzer determines the disinfectant level in the water, and generates a signal indicative of that level. When the disinfectant level falls below a predetermined level, a disinfection pump is activated to deliver additional disinfectant to the tank. The preferred disinfectant is Liquid Chlorine(sodium hypochlorite). The analyzer can measure the free available chlorine level, pH or oxidation-reduction potential of the water.

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 corrosive acid sulfate geothermal brine is mixed with a near neutral, bicarbonate geothermal brine containing above about 300 ppm silica to produce a relatively benign mixed brine of pH from about 4.5 to about 6.5 having reduced corrosivity as compared to the acid sulfate brine and a reduced tendency as compared to the near neutral, bicarbonate brine for depositing silica in equipment during brine processing.

Abstract: A low-cost water and wastewater treatment system having several embodiments achieves efficient contaminant removal in an environmentally "friendly" manner. The technology couples biological and passive chemical unit processes, and relies largely on pH changes to remove contaminants. A first embodiment focuses on a sequential two-unit treatment process consisting of a submersed aquatic vegetation (SAV) cell followed by a limerock (LR) bed. A second embodiment merges the two sequential treatments into one compartment where the LR bed is coincident with the SAV unit. A third embodiment describes the replacement of the SAV unit with a periphyton raceway unit, which is then followed sequentially by a LR bed. All three embodiments contain control elements for determining when and how much recycle within and flow between the treatment systems should occur, and if and when chemical addition should be performed.

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 and apparatus for automatically adjusting electrolytic production or feeding of a sanitizer such as halogen for treating a water body such as a swimming pool or spa. A microprocessor is responsive to sensors monitoring pH and temperature of the water body to predict demand for sanitizer which varies dependent on pH and temperature and direct a controller which automatically modifies the ON time during an ON/OFF cycle for the sanitizer production system in response to changing demand resulting from changing measurements in temperature and/or pH of the swimming pool water. The controller also modifies an ON/OFF cycle for a circulating pump when demand predicted by the microprocessor exceeds the capability of the sanitizer producer or feeder under an existing ON/OFF pump cycle.

Abstract: A method and apparatus for treating a liquid to inhibit growth of living organisms therein by adding to the liquid an active biocidal ingredient formed by mixing an oxidant and an amine source, by: producing a predetermined dilution of the oxidant; producing a predetermined dilution of the amine source; synchronously metering the two dilutions into a conduit to continuously mix therein according to a predetermined ratio to produce the active biocidal ingredient having high reproducibility, stability and efficacy in situ in the conduit; and continuously injecting the active biocidal ingredient, as it is produced in situ in the conduit, directly from the conduit into the liquid being treated.

Abstract: Method and apparatus for handling water used in plating processes to eliminate discharge of pollutants including a plating tank for chrome plating selected materials, at least one rinse tank which holds rinse water where parts from the plating tank are rinsed to remove chrome compounds used in the plating tank and transfer means to transfer water from the rinse tank to a purification tank where hydrazine is added to the rinse water in quantities sufficient to maintain selected pH in the water returned to one of the rinse tanks for precipitation of the chromic compounds to chromic hydroxide which can be easily filtered for disposal as a dry material. High quality water such as deionized water is added to the rinse tank to makeup lost water and a catalyst such as cobalt salt can be added to the purification tank to assist in reduction of the chromic compounds.

Abstract: A process for continuously controlling the pH value of an industrial process liquid removes impurities contained therein from the liquid and controls its pH value. If necessary, an aqueous solution having an acid or basic character is added. The purified process liquid having the desired acid or basic pH value is fed to the industrial process, maintaining the character of the aqueous solution constantly acid or basic by means of ion exchange resins and repeating the above steps. The system comprises a first tank (11) with a pH-meter (18) for the process liquid to be treated, a second tank (12) for the aqueous solution, pumps or the like (13,16) for recirculating the process liquid in the first tank (11) and supplying it to the industrial process and for recirculating the aqueous solution in the second tank (12), and a valve arrangement (20) for admitting to the first tank (11) the pH adjusting liquid to be added to the process liquid to be treated.

Abstract: This is a method of treatment of materials with the use of a sacrificial metal and reducible ions which comprises steps ofa) contacting the material to be treated with the surface of the said sacrificial metal, wherein the said material to be treated is included in an aqueous solution or emulsion or suspension; andb) inducing treatment processes at the surface of the said sacrificial metal by providing said reducible ions included in an electrolyte, wherein the said reducible ions react with the said sacrificial metal to form oxidation-reduction products comprising dissolved or suspended reduced species and dissolved or suspended species from oxidizing the said sacrificial metal.The method can be used for treatment of water, groundwater, including in-situ, wastewater, polluted gases, solid waste, and other materials.

Abstract: A water denitrification process is provided which comprises stopping the reduction of nitrate at nitrite, lowering the pH of the water, and then gas stripping the nitrite out of the water by using air as the gas in a sparger. This allows considerable savings to be realized based on the reduced chemical removal costs as compared to other water denitrification processes.