Abstract: An apparatus and method are shown for treating waste sludge. The apparatus includes a mixer housing having an elongated mixing auger therein. The housing has an inlet opening and an outlet opening with the elongated mixing auger being rotatably mounted within the housing between the inlet and outlet openings. A sludge conveyor supplies waste sludge to the inlet opening of the elongated mixer housing. An additive hopper contains an additive material to be combined with the sludge introduced within the mixer housing. A metering auger and series of spaced delivery conduits gradually introduce the additive material over a substantial interval of the mixing chamber beginning at a point downstream of the inlet opening to the mixer housing.

Abstract: A method for treating bioorganic or raw or treated wastewater sludge so that a stability based upon achieving a significant microbial population, conductivity level and percent solids, is developed rapidly, is provided for indefinitely and is independent of climatic conditions. A dewatered sludge that has not been treated (i.e., raw) or a sludge that has been treated to a PSRP level or a sludge that has been treated to a PFRP level, i.e., pasteurized or sterilized sludge when still in a wet condition, i.e., between 12%-30% solids, or when in a dry condition, i.e., between 30-60% solids, is mixed with alkaline adsorptive materials to reduce odor, to increase the percent solids and to facilitate granulation, is adjusted to a mildly alkaline pH, and is adjusted to an ionic conductivity which will allow the sludge to mature rapidly when seeded with a beneficiating microbial flora. This process will reduce the pH or a high alkaline treated sludge, e.g., often above pH 12, to a physiological pH of between 7 and 9.

Abstract: A method for reducing cyanide contaminants in refinery waste waters prior to reuse or release into the environment comprising adding to the waters a cyanide reactive scavenger comprising at least one amine-aldehyde reaction product.

Abstract: A method and apparatus to restore grey water resulting from a cleaning activity such as laundry using ozone as a cleaning agent in a closed loop system for recycling to preserve water, to reduce system size, and to enhance the efficiency of the cleaning system.

Abstract: An apparatus is disclosed for treating waste sludge. The apparatus includes a mixer housing having an elongated mixing auger therein. The housing has an inlet opening and an outlet opening with the elongated mixing auger being rotatably mounted within the housing between the inlet and outlet openings. A sludge conveyor supplies waste sludge to the inlet opening of the elongated mixer housing. An additive hopper contains an additive material to be combined with the sludge introduced within the mixer housing. A metering auger and series of spaced delivery conduits gradually introduce the additive material over a substantial interval of the mixing chamber beginning at a point downstream of the inlet opening to the mixer housing.

Abstract: A chlorination and dechlorination apparatus and method for the treatment of wastewater or other fluid comprising a chlorinator, a contact tank, and a dechlorinator. The contact tank is a vessel having an inlet opening and an outlet opening and is divided into two contact chambers by a baffle which runs vertically the entire length of the contact tank. A baffle opening is provided at the lower end of the baffle to allow passage of fluid from the first contact chamber to the second contact chamber. The chlorinator includes a chlorine tablet feeder and the dechlorinator includes a dechlorination tablet feeder. The fluid under treatment flows from inlet opening to the outlet opening in a plug-flow pattern. Previous to entering the contact chambers, the fluid washes over and dissolves chlorine tablets stacked in the chlorine tablet feeder. After flowing through the contact chambers, the fluid washes over and dissolves dechlorination tablets stacked in the dechlorination tablet feeder.

Abstract: Process for the hydrolysis of urea contained in the process water from plants for the synthesis of urea consisting of the thermic treatment of the water containing urea and of the removal by stripping of the compounds from decomposition of the urea (CO.sub.2 and NH.sub.3) in a series of stages in series with superimposed flow.The equipment is a vertical column with superimposed modules with weirs which penetrate in two successive modules and give the solution a rising movement.

Abstract: Aqueous streams are purified by use of ozone in one or more purification zones wherein the ozone is drawn from one purification zone to another by use of one or more eductors in each purification zone.

Abstract: A process wherein a liquid influent stream containing such an amount of a reactant that decomposition thereof to a desired concentration evolves, at the prevailing pressure and temperature, at least 0.5 volumes of gas per volume of the influent stream, is continuously passed through a volume of a particulate catalyst that is sufficient to decompose said reactant to said desired concentration and the evolved gas rises to the surface of said liquid and disengages therefrom into a gas space above said liquid, thereby providing an effluent stream having said desired concentration of said reactant.

Abstract: The invention pertains to the purification of commercial, industrial and institutional waste streams in order to bring them into dischargeable compliance with environmental standards. The invention provides a system for removing contaminants, such as fats, oils and grease (FOGs) and total petroleum hydrocarbons (TPHs), from waste effluents on an essentially continuous basis. During the treatment process, the FOGs and TPHs disposed within the textiles to be cleaned are treated with an alkaline, pH- or acid-sensitive detergent, causing their emulsification. The effluent waste stream is then treated by removing the solids and particulates. The alkaline emulsion is broken up by acidification of the wastewater, thereby releasing and dispersing the FOGs and TPHs. The FOGs and TPHs in the broken-up and dissolved emulsion are agglomerated by the introduction of an organic, cationic polymer.

Abstract: When adding flocculant to a sludge suspension, which will be dewatered, within a pressure pipe between a feed pump and a dewatering equipment, the distance between the dosing point and the inlet of the dewatering equipment will be modified during operation, e.g. by displacing a lance carrying a dosing head within the sludge pipe or by selectively operating a number of dosing points being positioned at different distances to the dewatering equipment. In this way it is possible to adjust most optimally the retention time being available for the formation and consolidation of floc particles with regard to the present operation conditions and the type of added flocculant.

Abstract: An apparatus and process for the removal and recovery of sulfides from tannery waste water or liquor. The apparatus comprises a closed vessel, the sulfide-bearing liquor is introduced into a first or acidulation zone of the vessel and mixed with acid to decrease the pH, preferably to a value below 4.0, and generate hydrogen sulfide. The acidified liquor is then overflowed into a second or desorption zone of the vessel and slowly agitated and conveyed through the second zone by disc conveyors to release the hydrogen sulfide gas from the liquor. A slight vacuum is drawn on the vessel causing the released hydrogen sulfide gas to be drawn into a third reaction zone of the vessel, where the gas combines with sodium hydroxide solution to form sodium sulfhydrate. The effluent from the second zone can be filtered or dewatered and the filtrate discharged to a disposal site while the proteinaceous solids can be recovered for use as fertilizer.

Abstract: The local reclamation system includes an accumulation tank for a soiled solution. A tank outlet valve selectively allows a flow of the solid soiled solution into the remainder of the system. A blend conduit leads from the outlet valve. An oxidizing supply selectively provides an oxidizing agent to said soiled solution downstream of the outlet valve in the blend conduit. A blend pump receives the soiled solution with oxidizing agent to promote the flow of the soiled solution through the system and a more uniformed disposal of the oxidizing agent throughout the solution. A six stage filter section selectively removes particulate matter. A biologic stage promotes a sterile reclaimed solution and a solution accumulator accumulates and stores the solution. Repeated injections of oxidizing agents occur before filter stage sections and pumps. The reclaimed solution can be reused or discharged without penalty.

Abstract: A mechanism for wastewater treatment which includes a plurality of solids settling chambers, at least a primary, secondary and a tertiary filter for selectively filtering waste water and effecting settling of solids of different sizes in the settling chambers and flow equalization ports for effecting demand flow of wastewater through the mechanism and the eventual discharge of high quality effluent. Chlorination and optionally dechlorination are effected as integral process functions of the wastewater treatment mechanism.

Abstract: A method and process for the treatment of liquids, including moving injection wands into a tank containing the liquid to be treated and injecting a treating solution through the injection wands to increase the reaction mixing between the injected treating solution and the liquid being treated.

Abstract: A method for treating wastewater sludge so that a stability based upon achieving a significant microbial population, conductivity level and percent solids, is developed rapidly, is provided for indefinitely and is independent of climatic conditions. A dewatered sludge that has not been treated (i.e., raw) or a sludge that has been treated to a PSRP level or a sludge that has been treated to a PFRP level, i.e., pasteurized or sterilized sludge when still in a wet condition, i.e., between 12%-30% solids, or when in a dry condition, i.e., between 30%-60% solids, is mixed with alkaline adsorptive materials to reduce odor, to increase the percent solids and to facilitate granulation, is adjusted to a mildly alkaline pH, and is adjusted to an ionic conductivity which will allow the sludge to mature rapidly when seeded with a beneficiating microbial flora. This process will reduce the pH of a high alkaline treated sludge, e.g., often above pH 12, to a physiological pH of between 7 and 9.

Abstract: A process is provided for removing ammoniacal values of potential environmental concern, both present and latent, from cyanate-containing waste streams and water-wet waste solids, typically generated in gold leaching or electroplating operations. The process includes heating the waste material to a temperature in excess of 50.degree. C. to convert ammonium cyanate to urea and optionally reducing pH to a range of 2.5 to 5 to accelerate hydrolysis of cyanate to ammonium carbonate, to supply ammonium ions for reacting with unhydrolyzed cyanate.

Abstract: Method of processing water including bath water and water employed in air treatment plants, which is conveyed in a circuit containing a contaminating point and a processing plant, the water exiting the contaminating point being contaminated water having a redox potential which is measurable and the method including, in the order recited, continuously measuring the redox potential of the contaminated water at the inlet of the processing plant; introducing into the contaminated water an auxiliary processing agent which is a mixture including a flocculating agent which promotes deposition of corpuscular pollutants and a halide which reduces ozone and disinfects the contaminated water as a function of the redox potential in such a way that the auxiliary processing agent is introduced in proportion to a drop in the redox potential; treating the water with ozone from an ozone generator in a spatial region defined within the processing plant and forming flocks including the corpuscular pollutants; and filtering the

Abstract: An apparatus for recovering oil from an oil spill on the surface of a body of water includes a skimmer unit for recovering an oil-water mixture from the surface of the body of water, a three stage coalescer unit for separating the oil in the oil-water mixture from the water therein and a solvent injection assembly for injecting solvent into the coalescer unit after the first and second stages in order to reduce the viscosity of the oil entering the second and third stages. The first, second, and third stages of the coalescer unit comprise interceptors having a surface area ratios between 27 and 65 ft.sup.2 /ft.sup.3 ; 65 ft.sup.2 /ft.sup.3 and 2500 ft.sup.2 /ft.sup.3 ; and 500 ft.sup.2 /ft.sup.3 and 4200 ft.sup.2 /ft.sup.3, respectively.

Abstract: A two-stage wet oxidation process for COD removal from high strength wastewater is disclosed. The wastewater stream is treated in a first stage subcritical wet oxidation zone at temperatures between about 250.degree. and 374.degree. C. to remove a substantial portion of the COD. Subsequently, all or a portion of the first stage oxidized waste stream is treated in a second stage supercritical wet oxidation zone at temperatures of 374.degree. to about 600.degree. C. to remove any remaining COD content. Both stages of wet oxidation treatment are carried out at essentially the same system pressure.

Abstract: A boat and method for treating a body of water which includes continuously scooping surface water as the boat traverses the lake. The method may include the step of adding a neutralizing agent such as lime to a body of water. To avoid forming "hot spots" in the body of water, water is continuously scooped from the surface and treated while in a barge which trails the boat. Neutralized water, instead of lime, is then returned to the lake at a predetermined depth. To treat as much water as quickly as possible, the scoops are funnel-like with parabolic portions, and conduits conveying water from the scoops have high velocity pumps to increase the velocity of the water relative to the speed of the boat. The barge includes a number of compartments for containing a variety of chemicals such as lime. The scooped water may be directed to one or more of the compartments.

Abstract: A chemical method of removing thiourea from spent hydrochloric acid cleaning solutions comprising the steps of: adjusting the pH to not less than 12 by addition of base to remove metal hydroxides; oxidizing thiourea to urea by the addition of at least a stoichimetric amount of oxidant per mole of thiourea; and further oxidizing urea to nonregulated/nonhazardous compounds by the addition of at least 3 moles of a hypochlorite per mole of urea. UV analysis confirms a greater than 98% removal of thiourea from solutions containing 0.4 to 2.7 wt. % thiourea after as little as 3 hours with an exotherm, .DELTA.t, of less than 105.degree. F.

Abstract: This invention pertains to a method of treating cyanide contained in wastewater with particularly high levels of solids in the stream. The process involves either simultaneous or step-wise dosage of hydrogen peroxide in the form of an aqueous solution of a concentration between 35% to 90% by weight, preferably at least 50% by weight, and SO.sub.2 either in the form of gaseous SO.sub.2 or solution of sodium and/or potassium sulfite or metabisulfite resulting in the conversion of cyanide ions to non-toxic cyanate ions.

Abstract: In accordance with the present invention, there is provided a system for treating commercial, industrial and institutional effluents to remove contaminants such as: fats, oils and greases, (FOGs) from the waste water. The system generally features a continuous processing treatment of the effluent, but can also be adapted on a small scale to a batch procedure. The system comprises the feeding of an emulsified waste stream to a first screening station, where solid matter and large particulates are removed. The FOGs in the waste stream are initially emulsified during the laundering or cleaning process by an alkaline detergent. The alkaline, emulsified waste stream is then fed to a first stage of a pH adjustment station. Here, the emulsified FOGs begin the process of being released and dispersed within the fluid, through the downward adjustment of the pH, i.e. by treating the effluent with acid.

Abstract: A system and method for treating wastewater containing industrial esters collected from grease traps at food establishments, septic tanks or from sludge digesters by increasing the pH of the wastewater to break down the ester. The increased pH wastewater is mixed to a predetermined mean velocity gradient which allows the influent to react. The reacted influent is then stabilized to lower the pH to normal levels suitable for input into a municipal wastewater treatment facility. Volatile gases are drawn off from all of the reactor tanks and placed into a treatment tank. In the tank a reduction of the bacterial and odor level occurs when the wastewater reacts with the chlorine-containing water output of the municipal wastewater treatment facility.

Abstract: A method for reducing the hydrogen sulfide content of hydrocarbon-containing fluids and aqueous solutions through a two-stage injection procedure whereby a dilute solution of a scavenging agent is injected into a hydrogen sulfide-containing fluid, followed by equilibration and a second injection of dilute solution of scavenging agent to further reduce the hydrogen sulfide content of the treated fluid.

Abstract: A process for removal of adsorbable organic chlorine (AOX) in which the acid-soluble AOX present in kraft chlorination (C.sub.D) effluents are destablized and converted to inorganic chloride by pH shift using the alkalinity and acidity sources available at the mill; C.sub.D effluent, typically having a pH of 1-2 and E.sub.1 effluent, typically having a pH of 9-12 can be mixed in various proportions to achieve a pH between 6.5-9.0 or the C.sub.D effluent is adjusted in pH to 6-11 with an alkaline composition so taht alkaline hydrolysis as well as precipitation of organic material occurs and the treated effluent contains less AOX than present in the original untreated effluents; the AOX removal is enhanced substantially by (i) the presence of a sulphide or (ii) by carrying out the alkaline treatment at elevated temperature and pressure.

Abstract: Automatic treatment of a drain system is provided by the controlled injection of a bio-active liquid at established intervals into the drain system. A container of the treatment liquid is provided with a pump coupled between the container and the drain. Fluid level sensing means is located in the container and fluid temperature sensing means is located in the drain system. When the temperature is within range and the fluid level is sensed, the pump is periodically operated to inject a quantity of fluid directly into the drain system without operator control.

Abstract: A process is provided for controlling the emission of hydrogen sulfide from, and the growth of living organisms in, steam condensate cooling towers and catch basins used in conjunction with steam and condensate of steam derived from hydrogen sulfide-containing geothermal brine. The process comprises contacting the condensate, in a substantially continuous manner, with a small, substantially less-than-stoichiometric amount of an oxidizing biocide, such as trichloro-isocyanuric acid or oxidizing biocide, such as trichloro-isocyanuric acid or 1-bromo-3-chloro-5,5-dimethyl-hydantoin, which results in the oxidation of such hydrogen sulfide precursors as ammonium bisulfide in the condensate to a water-soluble sulfite and/or sulfate, and which slows the growth of organisms in the cooling tower and catch basin.

Abstract: A gas, for example, oxygen which has low solubility in water is efficiently dissolved and reacted with a substance in a flowing liquid medium by injecting the gas into the flowing liquid at spaced apart points such that a bubble flow condition is maintained and the injected gas is dissolved and substantially consumed by reaction with the substance in the interval between adjacent injection points; in this way the gas is injected at a point at which the aqueous liquid has maximum dissolving capacity and the number of injection points can be minimized; in another embodiment oxygen injection is controlled to maintain a desired oxygen:liquid ratio effective for efficient dissolving of the oxygen while maintaining the bubble flow condition, however, this requires more injection points.

Abstract: A treating process is shown for removing cloggants from the pores and surfaces of aeration diffuser elements used in an activated sludge treatment process or the like. In this process, an acid solution is made to fill the aeration piping network, is fed through the plenum chambers that support the respective elements to be treated, and into the pores in said elements for reacting with the cloggants to be removed. The process is performed so that the acid solution fills the pores and contacts the surfaces of the diffusers and the plenums and the submerged piping network. The acid solution is reacted with the cloggants and is then agitated in contact with the diffusers and with the cloggants in the pores and on the surfaces of the diffusers to rejuvenate these elements.

Abstract: A process is provided for controlling the emission of nitrogen dioxide from, and the growth of living organisms in, steam condensate cooling towers and catch basins used in conjunction with steam and condensate of steam derived from ammonia and geothermal brine containing dissolved iron. The process comprises contacting the condensate, in a substantially continuous manner, with a small, substantially less-than-stoichiometric amount of an oxidizing biocide, such as trichloroisocyanuric acid or 1-bromo-3-chloro-5,5-dimethyl-hydantoin, which results in the oxidation of said nitrite formed by activity of bacterial in the condensate to a non-reactive nitrate, and which slows the growth of said bacteria in the cooling tower and catch basin. The process additionally includes periodically introducing into the condensate with amounts of a second biocide, such as dodecylguanidine hydrochloride or isothiazalone, which provides most of the control or organism growth in the cooling tower and catch basin.

Abstract: An apparatus for dispersing chemicals into an underwater pipe comprising first and second chemical feed pipes, the feed pipes being mounted to an intake pipe forming part of the underwater pipe, the first feed pipe extending along the length of the intake pipe and being connected to the second feed pipe, the second feed pipe being mounted to the intake pipe at that portion of the intake pipe adjacent an intake pipe opening, the second feed pipe including a plurality of inwardly extending releasing valves for dispensing chemicals into the intake pipe, the chemicals being delivered to the second feed pipe through the first feed pipe.

Abstract: A method and system for biofouling control of fluid containing structure of susceptible biofouling, wherein chlorine, hot water and/or some other control agent is injected by plural stages into the boundary layer, and chlorine residual, water temperature, or some other respective control parameter is maintained in the boundary layer just upstream of the next injection point.

Abstract: Wastewater is effectively disinfected while reducing both chlorine consumption and more particularly the levels of residual chlorine discharged from the wastewater treatment plant. The wastewater is first contacted with a sufficient amount of chlorine to satisfy the chlorine demand and to obtain as low a residual level of chlorine as possible. After the chlorine demand has been satisfied, the wastewater is disinfected with an effective amount of 2,2-dibromo-3-nitrilopropionamide.

Abstract: There is disclosed a method for the protection of metal surfaces against corrosion by the formation of a passivating coating of zinc silicate on the surfaces of the metals exposed to the water. The metal surfaces are preconditioned by contact with water containing a soluble zinc salt in an amount from about 0.5 to about 5 parts zinc per million weight parts of the water while the total alkalinity is maintained above 100 millequivalents by the addition of a water soluble alkaline material, as needed. The pretreatment passivates the metal surfaces with a coating of zinc carbonate, as can be determined by measuring the magnitude of external current flow between electrodes of a test probe maintained in the water.

Abstract: Gaseous ozone is admixed and stored with water under such conditions that the density of ozone in the water is increased above the normally obtained and held stabily at such levels so that it may be efficiently transported through the processing plant being cleaned. Specifically, the present invention provides for the chilling of the ozone and water carrier to increase density and permit the subsequent increase in temperature to cause propulsion of the water and ozone through the plant to be cleaned in-place.

Abstract: Process for the neutralization of a layer of acidic water over a sediment comprising a humic substance, according to which blocks of a sodium compound are made to fall through the water layer and to enter the sediment at least partially.

Abstract: A method of treating bodies of water such as lakes to correct chemical, biological or other imbalances in the aquatic environment by accurately dispensing a treatment agent into the water in an amount based upon the volume of water being passed over and continuously determined by detection means for the speed of the boat or vessel carrying the dispensing means and the depth of the weater being passed over. When the water is being neutralized by a chemical addition, the pH of the water may also be continuously monitored. A boat particularly designed and adapted for practicing the method is also disclosed. The boat includes a main tank partially supported or floated by the water at least when the tank is loaded and also stabilized and partially or additionally supported by lateral inwardly and outwardly adjustable pontoons when loaded. The boat includes sparging, or mixing, and above or below water dispensing means to dispense the treatment agent.

Abstract: The water content of wet small coal is reduced by adding a defined amount of an ionic surfactant, centrifuging, and adding a foam suppressing amount of a cationic organic compound to the aqueous effluent from the centrifugation step.

Abstract: A process is disclosed for separating an organic material from a composition comprising said organic material intermixed with particulate solids, the process comprising advancing a light hydrocarbon fluid through said particulate solids at an effective rate to drive at least some of said organic material from said particulate solids, adding water to said composition containing particulate solids and residual organic material to produce a second composition, and adding an oxidizing agent to said second composition in an amount sufficient to remove substantially all of the residual organic material.

Abstract: Iron pentacarbonyl is removed from sludge containing iron particles by treating with surfactants followed by oxidation with hydrochlorite ion.

Abstract: A chemical method of removing thiourea from spent hydrochloric acid cleaning solutions comprising the steps of: adjusting the pH to not less than 12 by addition of base to remove metal hydroxides; oxidizing thiourea to urea by the addition of at least 4 moles of hydrogen peroxide per mole of thiourea; and further oxidizing urea to nonregulated/nonhazardous compounds by the addition of at least 3 moles of a hypochlorite per mole of urea. UV analysis confirms a greater than 98% removal of thiourea from solutions containing 0.4 to 2.7 wt. % thiourea after as little as 3 hours with an exotherm, .DELTA.t, of less than 105.degree. F.

Abstract: Ozonization of the bath water taken from the reservoir (1) occurs according to the invention utilizing only 1% of ozone while using from 1 to 1.2 g/h of ozone in 700 l/h of (untreated) air from a convenient-to-handle ozonizer (7) of this capacity per 100 m.sup.3 of natural water. Ozonization occurs without ozonization reactors and ozone destroyers under pressure directly in the conduit (2) of the natural water stream Q. For this purpose. the ozone air is whirled with a partial stream (q) of the natural water in a flow spiral (9) to form an aerosol-like mixing condition and is blasted into the main stream of natural water. The high phase interfaces thus achieved effect rapid ozonization with quantitative ozone consumption. After the uncomplicated conversion of the baths with original pure chlorination operation to the ozonization-chlorination technique according to the invention, the chemical costs can be reduced by up to 70% with a simultaneous improvement in the water quality.

Abstract: In the particular embodiments of the waste water treatment system described in the specification, a waste water treatment basin has spaced-apart, moving aerator chains extending across the basin in a direction transverse to the flow of waste water through the basin. When an aerator chain is provided with air, bottom aerators suspended from the chain adjacent to the bottom of the basin move with respect to the basin to mix sludge collected on the basin with the waste water and to supply air to the waste water. A control system supplies air selectively to the aerator chains to provide zones of full aeration and intermediate zones with little or no aeration and the selection of the aerator chains is changed periodically in a progressive manner along the basin so that the zones move progressively through the basin.

Abstract: The instant invention relates to a process and apparatus for treating wastewater containing bentazon by decomposing the bentazon therein and thus eliminating or substantially reducing the bentazon content. This process comprises adjusting the pH of the wastewater to a value of less than 7 and heating it to a temperature of at least about 60.degree. C.

Abstract: The method of this invention is particularly, although not exclusively, adapted for effecting accelerated oxidation reactions in a downhole or deep well wet oxidation apparatus, including the processing of aqueous organic waste, such as municipal sludge. It includes injecting a multiple-phase composition which contains an oxygen or an oxygen-rich gas which is fully saturated with water vapor and which also contains water in the liquid phase into a wet oxidation reaction apparatus which contains an aqueous stream of combustible waste, preferably at the temperature and pressure of the waste stream at the point of injection. This reduces the likelihood of hazardous spontaneous combustion which may otherwise occur if dry spots are allowed to form in the reaction apparatus. The volume of water in the composition should be equal to at least twice the volume of water necessary to saturate the gas with water vapor to maintain at least 50 percent of the water in the liquid phase.

Abstract: The instant invention relates to a process and apparatus for treating wastewater containing bentazon by decomposing the bentazon therein and thus eliminating or substantially reducing the bentazon content. This process comprises adjusting the pH of the wastewater to a value of less than 7 and heating it to a temperature of at least about 60.degree. C.

Abstract: A process is described for the treatment of waste liquor containing a mixture of alkali metal or ammonium thiocyanate and polysulfides to convert the latter to the corresponding sulfates. The waste liquor is admixed with concentrated sulfuric acid under turbulent mixing conditions and in an inert atmosphere. The treated liquor is purged of gaseous by-products using an inert gas (e.g. carbon dioxide) and the purged liquor is treated to recover sulfate therefrom.

Abstract: A disinfection process is provided for preparing potable water having an unusually persistent and long lasting free available chlorine residual in order to assure safety and integrity of said water during its passage through the distribution system by which it is delivered to the consumer. The key step of this process is the generation of said unusually persistent free chlorine residual by mixing into a semi-finished water, which has already been pretreated specifically to satisfy substantially its immediate chlorine demand, dilute solution of HOCl having a pH between about 3 and about 6.