Abstract: Waste water from an apparatus that rinses particles from semiconductor wafers is collected in a tank. A pump sends waste water from the tank through a particle filter and onward to a supply inlet for initial rinse stages of the processing apparatus. Some of the waste water is bleed from the tank and replenished by fresh water introduced into the final rinse stage of the apparatus. If the semiconductor processing so dictates, chemicals may be added to the waste water to alter the pH and/or prevent the precipitation of solids in the tank. The addition of such chemicals can be controlled automatically in response to sensed characteristics of the waste water.

Abstract: A washer apparatus (10) includes a washing chamber (W) with a plurality of spray nozzles (N) and a pump (P1) for circulating the washing fluid (F) through the spray nozzles (N) for cleaning the contents of the washing chamber (W). A pH sensor (20) contacts the washing fluid (F) and a digital pH controller (30) connected to the pH sensor (20) generates digital pH values of the fluid (F). An acid neutralizing system (80) and an alkaline neutralizing system (90) are provided for selectively injecting acid neutralizer and alkaline neutralizer into the reservoir (S, T), respectively. An electronic controller (12) controls the operation of the washer (10) and the acid and alkaline neutralizer injection systems (80, 90) in response to the pH of the washing fluid (F) as determined by the digital pH controller (30).

Abstract: A wet scrubber control system is configured with a pH sensor and a conductivity sensor in the return solution, and with a conductivity sensor in the feed solution. Concentration of the scrubbing agent within the feed solution is determined using the conductivity of the feed solution, corrected by subtracting a bias therefrom. The bias is established by first measuring the concentration of scrubbing agent in the return solution using the pH sensor. An expected conductivity of the return solution is then looked-up. The bias is set as the difference between the expected conductivity of the return solution and a measured conductivity of the return solution.

Abstract: Methods and apparatus for monitoring and controlling pH, phosphate, and sodium to phosphate ratio in boiler systems operating with captive alkalinity chemistry are described. The methods for monitoring and controlling these parameters include the steps of determining the phosphate concentration via FIA, determining the pH, and using these values to determine the sodium to phosphate ratio. These values are then compared to the optimum values for the boiler system being treated; on the basis of this comparison, adjustments to the feed rate of water treatment chemicals being added to the system are then made. The apparatus includes a device for determining phosphate concentration via FIA, a device for determining pH, a means for determining sodium to phosphate ratio and a device for adjusting the feed rate of water treatment chemicals being added to the system. The device for adjusting the chemical feed rate is computer controlled.

Abstract: A process for conditioning recirculated evaporative cooling water in a cooling water system. The process reduces the amount of make-up water required during the operation of this system as compared to conventional water treatment systems. The process includes the steps of determining the pH of saturation. A strong cation exchange media is used in a controlled sidestream and operated so that the pH of the recirculated cooling water is within about a plus or minus 0.4 of the pH of saturation. The system avoids the necessity of storing acid at the water treatment site and also significantly reduces the amount of make-up water required.

Abstract: A water distribution system facilitates automatic corrosion control. The operator enters a set of values of parameters associated with water in the system. The system automatically and repeatedly measures the temperature and pH of the water. The system then computes a target pH for the water, according to a function which depends on the temperature and the other parameters, and on an index of corrosion. The system then varies the pH of the water, so as to minimize the deviation between the measured pH and the target pH. The system performs this process repeatedly, to maintain the desired properties of the water. In particular, the operator can easily and automatically control the water so as to make it either more corrosive or more scale-forming, in such a manner as to minimize the dissolution of lead or copper into the water while limiting the tendency of the water to form scale.

Abstract: In connection with processes for conditioning soft water (pH less than/equal to 6) to become drinking water, it is necessary to supply hardening agents in order to raise the carbonate-dissolving pH value into the neutral range. Subsequently the turbid materials are flocculated out and the flocculation products are filtered off. Finally, the calcite equilibrium must be set by means of a renewed addition of a hardening agent. This process is simplified by means of the invention in that the calcite equilibrium by means of the supply of highly pure lime water is only set after filtering off the flocculation products. In the flocculation stage, highly pure lime water is also preferably employed for setting the flocculation pH value.

Abstract: Embodiments of an apparatus and method for ferrite formation and the removal of heavy metal ions by ferrite co-precipitation from an aqueous solution at ambient temperature have been developed. Magnetically susceptible ferrite crystals can be continuously formed from aqueous solution and the heavy metal ion solution can be continuously treated by the ferrite co-precipitation process. The heavy metal ions are incorporated into the lattice points of the spinel ferrite structures. The precipitates of ferrite materials can then be magnetically separated. The main apparatus includes a ferrous sulfate mixing tank with a feeder assembly; a reaction tank or, alternatively, neutralization and oxidation tanks; settling and polishing tanks; and a magnetic separator. The reaction tank or oxidation tank includes an air distributor; a pH controller; and promoter feeding and ferrite product recirculating systems.

Abstract: For the removal of heavy metal contaminants from industrial waste water, a method is proposed for preparing a dense precipitate having superior handling and disposal properties. The method comprises incremental adjustment of the pH to maintain a low saturation ratio and recycling of slurry to provide seed crystals for secondary nucleation.

Abstract: A method for controlling fouling of a flashing vessel or heat-exchange surface exposed to a high-enthalpy geothermal brine tending to form silicon-containing scale. The method adds a silicon-complexing amount of fluoroborate species to the brine to form a fluid mixture that does not produce substantial amounts of the scale when the temperature of the fluid mixture is reduced. The addition does not significantly increase corrosion rates of mild steel heat-exchanger materials of construction.

Abstract: Sulfur-containing acid is produced at a geothermal energy source from hydrogen sulfide produced as part of a geothermal process and introduced into aqueous liquid brine to lower the pH of the liquid brine. The lowered pH of the brine inhibits silica, metal sulfide and/or calcite formation on the surfaces of geothermal energy processing equipment or in subterranean formations in which the brine is injected.

Abstract: The method of continuously controlling pH of an acid scrubbing liquid includes continuously withdrawing a constant partial stream from the scrubbing liquid; continuously measuring a pH in the partial stream with a glass electrode; adding base at a first rate to the partial stream upstream of the glass electrode and continuing the adding until the measured pH is in a pH set-point range of from 2.5 to 11.5; after the pH is in the pH set-point range, changing the first rate of adding base to the constant partial stream to compensate any subsequently occurring pH deviations; during the changing of the first rate of base addition, measuring the first rate of base addition to obtain a measured first rate; and automatically controlling a pH of the acid scrubbing liquid using the measured first rate as a controlling parameter by selecting a rate set-point range of the first rate of adding base to the constant partial stream so that the measured pH can be brought into the pH set-point range of from 2.5 to 11.

Abstract: A method for stripping ammonia from a film of digested sludge including flowing alkaline liquid sludge as a film on a tower's interior wall and flowing an ammonia stripping gas past the film creating a vapor containing ammonia and stripping gas; then disengaging the liquid sludge from the vapor in a tower disengaging zone.

Abstract: A process is provided for the alkaline stabilization of substantially liquid sludge which includes the steps of providing sludge of low solids content to a basin, and providing alkaline additive in sufficient quantity to the sludge in the basin to increase the ph of the sludge to a level above 12 by utilizing a sludge/alkaline blending Y. The blending Y has a sludge arm conduit, an alkaline arm conduit, and an exit conduit. Alkaline additive is provided to the alkaline arm conduit and recirculated sludge/alkaline mixture is drawn from the basin and is provided to the sludge arm conduit. A sludge/alkaline mixture containing newly added alkaline additive exits through the exit conduit of the Y. The recirculated sludge/alkaline and alkaline additive are mixed and thoroughly intermingled as they pass through the Y.

Abstract: A method for controlling the detoxification of aqueous solutions containing cyanides and/or cyano complexes, in particular zinc cyano complexes, with the use of a source for formaldehyde for glycolnitrile formation and a source for hydrogen peroxide for perhydrolysis of the glycolnitrile is disclosed. During the addition of the source for formaldehyde at a pH value in the range from 8.5 to 12 the pH value is kept constant by addition of an acid. The addition of the source for formaldehyde is discontinued if the pH value no longer increases.

Abstract: Methods for purifying aqueous waste streams containing a water reducible paint composition and equipment systems capable of conducting such methods are provided. In general terms the methods can be practiced by first providing an aqueous waste stream comprising a minor amount of a water reducible paint composition. This aqueous waste stream will commonly have a water content of at least 95 percent by weight. An acid, preferably sulfuric acid, is then admixed with the aqueous waste stream to form a suspension comprising water and precipitated paint compounds. Following the precipitation step a portion of the precipitated paint compounds are separated from the water.

Abstract: A method for the biological processing of organic substances and more particularly for anaerobic biological hydrolysis for subsequent biomethanization, with pH value control, in the case of which the dissolved and/or undissolved organic substances supplied to a first reactor are at least subjected to slight acidification in such reactor, the major part of the undissolved, at least partly acidified organic substances taken from the first reactor are supplied to a second reactor for the performance of at least one solids hydrolysis step and the main part of the dissolved, at least partly acidified organic substances from the first reactor and from the second reactor are supplied to a third reactor for the performance of at least one methanization step.

Abstract: A method for monitoring and controlling water quality in a water phase changing device, such as an ice maker, having a water inlet, a water outlet, a reservoir configured for retaining a supply of water and being in fluid communication with the inlet and the outlet, and a flow controller for controlling the flow of water into the device, such as an ice maker, includes the steps of monitoring TDS concentration of water retained in said reservoir, and actuating at least one of a water input controller and a water dump controller to adjust the composition of the water in the reservoir when the monitored TDS concentration exceeds a preset TDS target concentration.

Abstract: A control circuit device of a reverse osmosis drinking water machine has a microcomputer unit controlling the working of various peripheral circuits and enabling the drinking water machine to determine the quality of the drinking water and to clean automatically the filtration elements of the basis of the determined quality of the drinking water. The device is further provided with an output unit capable of giving an advance warning to remind the user of the need of replacing the worn-out filtration elements. The output unit is also capable of terminating automatically the water-making process when the PPM value of the drinking water so made is not in conformity with the health standard.

Abstract: The water remediation and purification method includes a cavitation nozzle which is operated with a throat size and pressure drop to incur cavitation in the water. The explosive and implosive bubble growth and collapse produces free radicals which interact with contaminants in the water to oxidize the contaminants. The cavitation process is enhanced by (1) a variable throat nozzle, (2) recycling the product back through the nozzle for further oxidation, and (3) programmable control feedback. Subsequent ultraviolet radiation from high energy lamps, ion exchange and/or degassifying treatment can be employed to produce water quality within acceptable levels.

Abstract: A land vehicle system for collecting crude oil and other contaminants which have been spilled on snow and ice covered surfaces includes a crawler tractor having an auger type collection and transfer mechanism mounted forwardly thereof for skimming the contaminant and a layer of snow and/or ice from the Earth's surface. The recovered oil and snow and/or ice are transported by a vacuum line to a storage and transport vehicle towed by the tractor. The storage and transport vehicle may be self-propelled and includes an onboard storage tank which is heated to melt the snow and/or ice and a separator for separating air used to transport the contaminated snow and/or ice to the tank. The tractor includes onboard prime movers for operating a vacuum pump for collecting the contaminated snow and/or ice and a prime mover for propulsion and operation of the skimming and collection mechanism.

Abstract: A pollution control apparatus (10) for controlling water-based liquid waste includes a vacuum distillation vessel (14) for separating water-based liquid waste into a distilled water component and a pumpable sludge component. A pH control system (12) allows the vacuum distillation vessel (14) to operate at maximum efficiency, and a purification system (22) allows the distilled water component to be purified to a level capable for reuse in chemistry, or else suitable for direct discharge into a municipal sewer. A microprocessor allows the apparatus (10) to operate automatically.

Abstract: A system for the preparation of a lime slurry and metering of the slurry, which prevents scaling and plugging of equipment and piping. The elimination of scaling and ease nof metering are achieved by a combination of process steps in an automated operating sequence. The system is particularly adaptable to the addition of lime to municipal water systems for reduction of the acidity of the water.

Abstract: A method of cleaning waste water and removing contaminants therefrom with respect to compositions exhibiting water solubility behavior which is pH dependent. The method includes the preliminary step of applying the composition at a pH at which the composition is water insoluble, then removing excess composition from application equipment with a wash solution having a pH at which the composition is water soluble or washable, changing the pH of the wash solution to a pH at which the composition is water insoluble to thereby precipitate the composition and removing the composition by filtration or other separation techniques. The invention also relates to a shop towel clean up method.

Abstract: An automatic system to precisely maintain bactericidal action in a reservoir of water equipped with a recirculation system, such as a swimming pool, decorative fountain, spa, cooling water reservoir or the like. The automatic system includes: a service loop which bypasses a portion of the recirculating water past sensors which measure the pH and oxygen reduction potential (ORP) of the water and in which acid and halogen are injected by a chemical feed unit; an electronics unit for determining the injection quantity of the acid and/or halogen needed to restore pH and ORP to stored set-points, and for controlling the chemical feed unit in response to the injection time determination; and an optional telecommunication unit for reporting process control status to a remote location and allowing modification of the process parameters, selection of operating modes, and performance of diagnostic tests from the remote location.

Abstract: The process relates to the reinhibition of recycled antifreeze/coolant. The process is particularly well suited for use with recycled, used antifreeze/coolant from the cooling systems of internal combustion engines.

Abstract: An ash scoop which remains out of the water during most of its operation. The ash scoop has a retaining and a nonretaining configuration. It moves along a track downward into the pit while poised in its nonretaining configuration. Once in the pit, it moves to its retaining position to grab debris within the pit. It then moves back out of the pit along the track until it reverts to its nonretaining configuration to dump the ashes dragged out of the pit.

Abstract: A wastewater treatment system and method for chemical precipitation and removal of metals from wastewater in a continuous or batch treatment process includes an ion-selective sulfide electrode and a reference electrode disposed in a precipitation tank for measuring an electrochemical potential therebetween in a predetermined range. A controller unit is provided which is responsive to the electrochemical potential in the predetermined range and is connected to a precipitant feed unit for automatically controlling the chemical precipitant fed into the precipitation tank.

Abstract: The water remediation and purification apparatus includes a cavitation nozzle which is operated with a throat size and pressure drop to incur cavitation in the water. The explosive and implosive bubble growth and collapse produces free radicals which interact with contaminants in the water to oxidize the contaminants. The cavitation process is enhanced by (1) a variable throat nozzle, (2) recycling the product back through the nozzle for further oxidation, and (3) programmable control feedback. Subsequent ultraviolet radiation from high energy lamps, ion exchange and/or degassifying treatment can be employed to produce water quality within acceptable levels.

Abstract: The Langelier index and pH of city drinking water are improved by mixing and reacting a slurry of calcium carbonate and slaked lime covered with calcium carbonate produced in a slaked lime dissolving vessel with carbonic acid-containing water in a mixing and reacting vessel to make a calcium hydrogen carbonate aqueous solution which in turn is continuously added to water in a water-receiving vessel together with the aqueous solution of slaked lime. As a result, unused undissolved matter is decreased, and the Langelier index of drinking water can be improved.

Abstract: A system for the preparation of a lime slurry and metering of the slurry, which prevents scaling and plugging of equipment and piping. The elimination of scaling and ease of metering are achieved by a combination of process steps in an automated operating sequence. The system is particularly adaptable to the addition of lime to municipal water systems for reduction of the acidity of the water.

Abstract: A process and device for combined oxidation of polluted water, e.g. industrial waste water or effluents, to make it suitable for drinking, involves injection of hydrogen peroxide (pure aqueous solution or diluted) and ozone (gaseous, or ozonized oxygen or air) simultaneously and in a flow direction co-current with the circulation of the water to be treated, at the inlet of the oxidation reactor. For example, a reactor is endowed with mechanisms to inject ozone and hydrogen peroxide at its base, at very closely-spaced points and simultaneously, in a flow direction the same as the water to be treated, with an automatic control system to regulate the levels of the oxidizing agents.

Abstract: A treatment method for removing arsenic from water includes conditioning the water with one more additives including an iron salt, an acid, and an oxidant until the water contains more ion than arsenic, is acidic, and has an ORP of about plus 600 mV. A reagent is then added to the conditioned water until it becomes basic and the water and additives are then reacted in a reaction chamber wherein iron and arsenic are co-precipitated in the form of iron arsenate and iron hydroxide or iron oxide. Treated water is then separated from the precipitate by settling of filtering.

Abstract: A method of removing scale in a cooling water system in which scale is formed comprises adding 0.01 weight % or more based on the total amount of water contained in the cooling water system of a copolymer containing vinyl monomer units having a carboxyl group or salt thereof and vinyl monomer units having a sulfo group or salt thereof in amounts to make the mol ratio of the carboxyl group to the sulfo group in the range of 30:70 to 95:5 and having weight average molecular weight calibrated with polystyrene in the range of 1,000 to 100,000 to the cooling water system while operating the cooling water system and the cleaved or dissolved scale is discharged out of the cooling water system by blowing.

Abstract: A method and apparatus for automatically measuring the acidity of overhead water in an oil refinery, and dispensing a neutralizing agent into the refinery system at a rate responsive to that measurement. A sample of overhead water is collected and passed through a filter and cation exchange resin. The acid concentration of the sample is then automatically measured and a signal generated based on the concentration. The signal goes to a controller which controls the dispensation rate of neutralizing agent into the refinery system, thus reducing the acidity of the overhead water and limiting the corrosive effects of such acidity.

Abstract: An automatic control system for maintaining the quality of water in a cooling tower utilizes a probe which senses the oxygen reduction potential (ORP) of the water for activating a chemical supply means, in accordance with a pre-established ORP measurement, to maintain the ORP of the cooling tower water between lower and upper limits. A second sensing probe measures the conductivity (in MHos) of the water as a factor of the total dissolved solids (TDS) to control the bleed-off or blow-down of the water. The chemicals, which are supplied for maintaining the ORP, permit significantly higher total dissolved solids in the water than with standard cooling tower systems, without the buildup of scale. As a consequence, water consumption is significantly reduced; and the system functions automatically, without requiring periodic visual inspection, water analysis or manual operation.

Abstract: The acid scrubbing liquid which has a pH value below 3 and is used in a scrubbing zone to remove acid components from a gas. At least part of the scrubbing liquid is circulated. A partial stream of the scrubbing liquid at a constant rate is mixed with an alkaline solution stream which has a constant concentration and is supplied at a constant volume rate, the pH value of the resulting mixture is continually measured, a setpoint in the range from 5 to 9 is selected for the pH value of the mixture, and a neutral or alkaline correcting liquid is added to the scrubbing liquid in response to a decrease of the measured pH value below said setpoint. The scrubbing liquid may mainly consist of water.

Abstract: A process for controlling corrosion in a wet oxidation system by controlling the operating pH range within the system is described. A pH operating range is selected within which corrosion to the wet oxidation system is minimized. The pH within the wet oxidation system is monitored and a pH adjusting material is added to the waste material being treated to maintain the system pH within the selected pH operating range, thus minimizing corrosion.

Abstract: A method and apparatus for carbonating a liquid by creating a pressurized atmosphere of carbon dioxide in a container, spraying a liquid, including a caustic containing liquid, into the atmosphere to cause an interaction between the liquid and the carbon dioxide, collecting a pool of liquid in the bottom of the container, and sparging carbon dioxide under pressure through the pool, and an apparatus for same.

Abstract: A batch type process for purification of a polymer resin, in which a predetermined volume of acid is rapidly emptied and stirred into a fixed volume of polymer slurry for chemically treating impurities in the slurry, is converted to a continuous operation by supplying a substantially constant stream of polymer slurry and a controlled stream of acid to a mixing vessel. pH control of the polymer slurry required for effective purification of the polymer resin is achieved by manipulating the flow rate of the acid stream responsive to a feedforward control signal which operates in conjunction with a feedback signal. The feedforward signal is based on an upstream measurement of slurry flow rate to the mixing vessel and the feedback signal is based on a downstream pH measurement of slurry flowing from the mixing vessel.

Abstract: A process and system for continuously recovering industrial waste water characterized as divergent hydro-lipophilic waste streams for industrial reuses to enhance water conservation and to reduce environmental pollution is disclosed. The process and system are especially suited for reclaiming animal and food processing discharge water having blood, fat, oil and grease contaminants in the water, for industrial reuse in evaporative condensers, hydraulic system cooling and equipment, non-food contact vehicles and plant or factory area wash-downs. The process can operate continuously for supplying water for such industrial uses, but also includes an automatic shut down if the incoming influent to be treated is too turbid. The process includes chemical pH adjustment, separation of fat, oil and grease (FOG) from the influent and particulate removal in polishing filters. Sensors are used to monitor the pH and component internal water pressures throughout.

Abstract: The continuous treatment of a liquid stream for removing a selected component therefrom, includes depressurizing the liquid stream to remove carbon dioxide, forming a carbon dioxide stream and a component-laden stream (17); raising the pH of the component-laden stream (17) to form a pH adjusted stream (19); gas-stripping the component-laden, pH adjusted stream (19) with a counterflow stripping gas (73) in a stripping column (20) having a plurality of deflection cones (111) over which the pH adjusted stream (19) is sprayed, to remove the component therefrom and thereby forming a relatively component-free liquid stream (50) and a gaseous component stream (21); cooling the carbon dioxide stream; neutralizing the liquid component stream (21) with the cooled carbon dioxide stream (64); cooling the gaseous component stream (21); re-heating the gaseous component stream to form a heated stream (35) and dissolving the heated gaseous component stream (35) in an acidic solution in a re-absorption column (36) forming a r

Abstract: A method for controlling fouling of a heat exchange surface exposed to a high-enthalpy geothermal brine tending to form silica scale, but containing less than a saturated amount of cations capable of reacting with sulfates. The method adds a limited amount of sulfuric acid to the brine to form a mixture. The amount of sulfuric acid is limited to that required to produce sulfates sufficient to apparently complex with silica, but less than the amount required to increased the sulfates to above saturation amounts of sulfate reacting cations, significantly reducing or virtually eliminating sulfate and silica deposits and fouling. The addition is further controlled to an amount which reduces the pH of the mixture to no less than about 4.5. The addition does not significantly increase corrosion rates of mild steel heat exchanger materials of construction.

Abstract: A method for treating water in a cooling system including a cooling tower and heat exchanger are disclosed herein. The method includes the steps of removing water from the main cooling water circuit, serially subjecting the water to magnetic treatment, treatment with ozone, filtering with a centrifugal separator, and then returning to the main cooling water circuit. Underflow from the centrifugal separator is filtered with a bag filter, and the filtered water returned to the magnetic treatment step. The pH of the water may be controlled by regulating the production of dry air supplied to the ozone generator.

Abstract: A process for the removal of ammonium from aqueous liquids, especially from fermentation broths, is disclosed. The process uses a cation exchanger membrane which separates a liquid on a donor side that is to be depleted of NH.sub.4.sup.+ from a solution on an acceptor side whose pH is higher than on the donor side. Because of the equilibriumNH.sub.4.sup.+ .revreaction.NH.sub.3 +H+there is on the acceptor side increased formation of NH.sub.3. This is continuously removed, in particular by reducing the pressure and/or passing through inert gas, or by selective transport through another microporous membrane into an acid protonation solution, so that a NH.sub.4.sup.+ concentration gradient is maintained across the membrane. A similar content, apart from the ammonium concentration, of concomitant cations on the donor and acceptor side and/or a high ratio of the solution volumes on the donor side and the acceptor side ensures that the solution on the donor side to be depleted of NH.sub.4.sup.

Abstract: This invention discloses an in-situ process or method for cleaning the interior surfaces of a swimming pool or the like for removing stains, scale, calcium deposits, and the like, and without the need for draining the pool. The chlorine content of the pool is initially tested, and chlorine is added to bring it up to a level sufficient to prevent algae growth for a period of up to 10 days without filtering. Water is added to the pool to insure all water line marks are sufficiently immersed so as to benefit from the cleaning operation. An acid wash solution, including a mixture of hydrochloric acid and a strong metal chelating agent, is then applied in-situ or as close to the surfaces to be cleaned as possible. As the stains, scale, and deposits dissolve, a strong organic acid such as oxalic acid is added to precipitate out the undesirable materials and cause them to settle down to the bottom of the pool for subsequent vacumming.

Abstract: The invention is directed to an apparatus for washing a solvent in the recessing of irradiated nuclear fuel. The solvent is washed with an aqueous solution in a mixer-settler having at least one stage which includes a mixing chamber and a settling chamber. The pH is measured by a sensor adjacent stirring means in the mixing chamber and is coupled to a controller controlling metering of the washing solution. The pH of the dispersion in the mixing chamber is measured and an amount of washing solution is added which influences the pH toward the desired operational value. Various recycling means and weir overflow means also influence pH control and the washing operation.

Abstract: The present invention is concerned with a process for enhancing the dewaterability of a waste sludge having a substantial content of water-retaining cellular structure arising from microbiological action and having a solids content of at least fifteen percent by weight. The pH of the sludge is adjusted to 4.0 or less, the sludge is subjected to heat treatment to significantly enhance its filterability, the pH is again adjusted to near neutral, the sludge is subjected to a second heat treatment step, and the sludge is filtered to a final solids content in excess of about fifty-five percent by weight.

Abstract: In the processing of a geothermal brine and the recovery of heat therefrom, there are produced a non-condensable gas stream containing hydrogen sulfide and carbon dioxide and a liquid stream comprising a condensate of steam derived from the brine. In accordance with the present invention, the noncondensable gases are introduced into the condensate in the presence of an oxidizing agent to form a gas-liquid mixture. The mixture is maintained at an alkaline pH for a time sufficient for a substantial portion of the hydrogen sulfide to be oxidized. Thereafter, the mixture is introduced into a gas-liquid separation zone for separate recovery of a gas stream comprising a major amount of carbon dioxide and substantially free of hydrogen sulfide. Advantageously, the recovered gas stream is recycled to the geothermal brine process to reduce the pH of the brine and its scaling potential.

Abstract: A process and an apparatus are disclosed for the monitoring and treatment of circulating water of open circulation systems, preferably in cooling tower circulation systems, in which at least one partial minor stream is continuously diverted from the main circulating water supply and directed through a compact module in which, in an automatic sequence, the pH value of the partial stream is measured and adjusted by the addition of any necessary acid, the conductivity of the partial stream is measured, preferably inductively, and an elutriation unit is activated to drain excessively conductive water, corrosion inhibitor is added to the partial stream in dependence upon the quantity of fresh water added to the circulating water, organic and/or inorganic biocides can be added and the partial stream is filtered and returned continuously to the main circulating water supply.