Abstract: Sampling pipes 21 and 22 are inserted, separated from outlet openings, into first and second water softeners 4 and 11. Raw water flows through first water softener 4, and raw water does not flow through second water softener 11. Once the hardness component concentration of the treatment water sampled by sampling pipe 21 reaches a specified concentration, the watercourse selection of valves 2 and 6 and valves 9 and 13 are switched, causing raw water to flow through second water softener 11. First water softener 4 is regenerated by salt water from a salt water chamber 14. The resulting water softening device prevents the leaking of hardness components, even with there is a fluctuation in the water quality of the raw water or when there is performance deterioration in the ion exchange resin.

Abstract: A process is provided for removing CO2 and/or H2S from a gas mixture containing as impurities CO2 and/or H2S and at least one other impurity selected from the group consisting of a cyanide and ammonia. The process includes contacting at least a portion of the reflux stream from the overhead vapor from a stripping column of an acid gas removal solvent (i.e., alkanolamine) treatment plant with an anion exchange resin to remove corrosive impurities. The ion-exchanged reflux stream is then recycled to the top of the stripping column or into the bulk circulating acid gas removal solvent (i.e., alkanolamine) passing from the bottom of the stripping column.

Abstract: A method for purifying contaminated water involves passing contaminated water through a porous bed of steel slag. The steel slag can be used to remove various contaminants or reduce the concentration of such contaminants, such as heavy metals (for example, hexavalent chromium), chlorinated organic compounds, and certain inorganic anions. The method preferably involves placing an underground barrier of a porous bed of steel slag in a flow path of contaminated groundwater then allowing contaminated groundwater to pass through the barrier to purify the contaminated groundwater. The slag particles may be used as produced with no further grinding necessary, although the slag may be passed through a sieve or sieves to obtain a set of slag particles having a median diameter of about ⅛ inch to 1 inch, and preferably between about ¼ inch to ⅜ inch. Due to the inherent permeability of slag, no additive need be mixed with the slag.

Abstract: A method for generating high purity acid or base in an aqueous stream for use as an eluent for chromatography and, particularly, ion chromatography. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed having a first strongly acidic and a second weakly acidic portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Anions to be detected and the generated eluent flow through a chromatographic separator. The chromatographic effluent flows past a detector.

Abstract: A method (20) for using a weak acid resin (30) to remove dissolved metal from an aqueous-based stream (36), includes reneutralizing the weak acid resin (30) a plurality of times before regeneration of the weak acid resin (30) to remove the taken-up metal. The present method (20) allows up to 30 times greater volumes of water to be run through the same weak acid resin (30) before regeneration with acid is required, and also inherently adjusts the pH of the effluent (40) to an acceptable level of between about 6 and 9.

Abstract: A process for the reclamation of spent aqueous alkanolamine solutions by contacting a spent aqueous alkanolamine solution with a strong base ion exchange resin for time sufficient to sorb from the aqueous alkanolamine solution at least a portion of the accumulated ions and after a high concentration of ions accumulate on the resin, regenerating the strong base ion exchange resin by: a) purging the resin with water or nitrogen, b) contacting the strong base ion exchange resin with a sodium chloride solution for a time sufficient to remove the ions, c) purging the resin to remove the sodium chloride solution, d) contacting the resin with an alkali metal hydroxide solution, preferably sodium hydroxide, for a time sufficient to convert the resin to a substantially hydroxide form; and e) purging the resin, wherein the ion sorption capacity of the resin is maintained at a substantially constant value.

Abstract: A controller and corresponding method have been developed for controlling recharging of a water conditioning apparatus. The apparatus includes an input component for receiving measurements of water usage by the apparatus, a storing component configured to store, for each time slot of a cyclically repeating series of time slots, values dependent upon an average of the measured amounts of usage in that time slot and in at least one other corresponding time slot in a previous cycle, and a determining component configured to determine, at least in part, a time for recharging the apparatus in dependence upon the stored value.

Abstract: An apparatus and method are described for determining precisly when the resin column in a deionized water generator needs to be regenerated. This is achieved by causing the untreated water to pass through a flowmeter and by measuring its electrical conductivity and temperature. After subtracting the value for pure water from the conductivity value and correcting for temperature, the two numbers are converted to an impurity concentration which is multiplied by the flow rate to give a value for weight of impurity per unit time. The latter value is integrated over time by accumulating sample values read at regular intervals, thereby generating a dosage value. This dosage may be displayed for viewing and/or compared with the known capacity of the system's resin column so that an alarm may be sounded when regeneration is needed.

Abstract: A waste water stream containing cyanide bearing compounds and heavy metals such as copper, silver, nickel, iron and the like is directed from a source after pH adjustment to a first tank containing adsorption material in the form of granular activated carbon. The waste water is oxygenated by compressed air. The cyanide bearing compounds and heavy metal are adsorbed onto the surface of the adsorption material which is pretreated to an initial pH in the range between about 8.5 to 11. The effluent from the first tank is pH adjusted by a pH controller which adds a caustic solution to the effluent to maintain a control point pH. The pH adjusted effluent is directed toward a second tank containing pretreated adsorption materials. The water stream free of cyanide and metal contaminants is directed to an effluent tank for safe discharge. Thereafter a stripping solution preferably containing sulfuric acid is circulated through the tank to remove the adsorbed metal for the adsorption material.

Abstract: This invention relates generally to a method for the extraction of organic liquid contaminates from a sample. This invention is directed to the ability of hydrophobic extraction material or ribbon tape made of a hydrophobic polymer to facilitate the extraction of liquid organic contaminates from an aqueous sample in contact with an organic non-polar solvent.

Abstract: A method for resolving sludge/emulsion formed as a result of acidization of oil and gas wells comprising the steps of adding an iron-control chemical in an amount sufficient to prevent the formation of insoluble iron compounds, and adding a water-dispersible emulsion breaker in an amount sufficient to separate the sludge/emulsion into clean oil and water. Further treatment of the waste water with water clarifiers, settling vessels and passing it through a macroreticular resin results in water that is at least less than 29 mg/L total oil and grease for overboard discharges from offshore facilities.

Abstract: The subject matter of the present invention is a process for the purification of a virtually anhydrous organic liquid other than DMSO alone, in order to decrease its content of alkali and alkaline-earth metal and metal cations, characterized in that it consists essentially in placing this organic liquid in contact with one or more cation exchange resins and in then separating from the resin(s) the purified organic liquid, said resin or at least one of said resins being a sulphonic resin in --SO.sub.3 H or --SO.sub.3 NH.sub.4 form based on a polystyrene-divinylbenzene copolymer having a divinylbenzene content of from 50 to 60% by weight, without taking the sulphonic groups into account.

Abstract: An apparatus and method for separating oxides of heavy isotopes of hydrogen (deuterium oxide, oxides of tritium and mixed isotope oxides) from light water (H2O) which is contaminated with these heavy hydrogen isotopes such as that currently being discharged in cooling water from nuclear power plants. A central aspect of this invention includes a plurality or bundle of elongated hollow core fibers which are positioned within an elongated enclosed housing having a feed water inlet, an exit stream outlet, and a permeate outlet. At least a portion of the hollow core fibers are at least partially filled or packed with small beads which are comprised of a porous exchange resin carrying waters of hydration. Porosity is controlled by the degree of cross-linking and bead diameter of the exchange resin which is preferably combined with aluminum sulfate or ammonium hydride to form (RSO.sub.3).sub.3 Al or RSO.sub.3 NH.sub.4.

Abstract: A modular water treatment and purification system, suitable for home use, is connected to a water supply and contains a closed fluid treatment circuit extending to a water outlet. The closed fluid circuit flows through a plurality of replaceable water treatment modules each having a specific water treatment function, such as the removal of a particular material from the water by the use of filtration, carbon adsorption, ion exchange or the addition of a chemical to balance the desired water conditions. Preferably the circuit also includes traversing a radiation device, for example an ultra violet light, for the purpose of sanitizing the water.

Abstract: An improved water softening process is provided which also reduces anion content. A first stream of water is passed through an anion-exchange unit to remove undesirable anions and raise the pH. The first stream of water is then provided to reactor/clarifier water softening equipment, where it acts as a source of hydroxyl ions. Preferably a second stream of water which did not pass through an anion-exchange unit is also provided to the water softening equipment. The streams of water are combined and processed through the softening equipment, where hardness ions are precipitated out, yielding softened water with reduced anion content. The anion-exchange system utilized preferably has a counter-current continuous resin train and a counter-current continuous resin regeneration unit.

Abstract: An apparatus for generating high purity acid or base in an aqueous stream for use as an eluent for chromatography and, particularly, ion chromatography. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Anions to be detected and the generated eluent flow through a chromatographic separator and a detector. In one embodiment, between separation and detection, the separated anion stream flows through a second cation exchange bed with no electrical potential applied. The second bed serves as a suppressor. After completion of the desired number of cycles, flow through the first and second cation exchange beds may be reversed by appropriate valving for the next sample stream.

Abstract: A process for regenerating a solvent from a waste extract after use in a remediation process includes monitoring the water content and the amount of organic contaminants in the extract. If the water content in the extract is above a predetermined threshold value, the extract is distilled to yield the solvent therefrom for reuse in the remediation process. If the water content is below the threshold value but the amount of organic contaminants is above a predetermined limit, the extract is also distilled to yield the solvent therefrom for reuse. If the water content and amount of organic contaminants are both below their respective predetermined parameters, the extract is filtered through a molecular sieve to yield the solvent therefrom. The yield solvent is then collected from the distillation and filtering processes, and the regenerated solvent is then reused in the remediation process.

Abstract: An apparatus for equalising pressure and flush in a vessel (1) has a chromatographic separation chamber (5), a distribution plate (3) or collection plate located in the vessel, a pressure equalisation chamber (4) defined at least in part by the extremity of the vessel and by a first face of the plate, the separation chamber (5) being defined by a second face of the distribution or collection plate, a first conduit (6) which places a first fluid in communication with the distribution or collection plate, the separation chamber (5) communicating with the equalisation chamber (4) via a flush chamber (10) comprising a first opening (21). A line (9) for supplying a second fluid which is substantially pure or substantially non contaminated is directly connected to the flush chamber at a point such that a portion of the second fluid can circulate towards the pressure equalisation chamber via a further opening (20) and the remaining portion can circulate towards the separation chamber via the first opening (21).

Abstract: Wastewater discharge, which is generated in an ion exchange regeneration system having a cation exchange bed and an anion exchange bed, is minimized by circulating a displacement rinse through a cation exchange bed, saving an effluent of the displacement rinse to be used as a regenerant solution in a subsequent cycle, circulating the remaining rinse in the cation exchange bed through an anion exchange bed that has been exhausted by service flow, circulating a displacement rinse through the anion exchange bed, and circulating a final rinse through the cation and anion exchange beds. The volume of wastewater discharge can be reduced to a degree of approximately 80-90% of a typical conventional system, i.e., waste water discharge can be reduced to 1-2 bed volumes. Storage tanks, automation valves, etc. can be eliminated while high reduction of wastewater discharge is effected.

Abstract: Method for controlling with precision a permanent in-line process for separating constituents of a mixture in a simulated moving bed separation system from concentration and flow rate measurements.The system comprises a set of columns forming a closed loop comprising several zones between fluid injection and draw-off points. Control of the process (linear or nonlinear) is performed from a knowledge model and from a certain number of operating variables at a plurality of measuring points along the loop (concentrations and flow rates for example) and characteristic measurements of the fluids injected and drawn off. Ratios respectively indicative of the ratio, in each of the different zones, between the fluid flow rates and the simulated adsorbent material flow rates, are determined from actual values of controlled variables depending on the measured operating variables (purity of the constituents, system yield, etc.).

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: A control unit for operating a valve system in a water conditioner system includes a drive motor having an output shaft coupled to the valve system, a valve position slide switch, an electronic regeneration controller, and a settable mechanical clock. The electronic controller can be programmed by the use of electrical jumpers/dip switches/control knobs. As the drive motor drives the output shaft coupled to the valve system, the drive motor also contemporaneously rotates a dual lead screw in the valve position slide switch. The dual lead screw drives an electrical contactor along a series of electrical contacts in a closed loop fashion. Each of the discrete electrical contacts corresponds to a position of the valve. The electronic controller controls the position of the valve in accordance with dwell times programmed into the electronic controller. If a demand regeneration scheme is desirable, a hardness setting rotary potentiometer can be used to provide analog electrical control.

Abstract: A method for the removal and purification of substantially all of the fluoride ions contained in a solution containing greater than 10 parts per million (ppm) fluoride ion, a mixture of other anions, silicon in the form of a fluorosilicic acid, silicic acid, silicates, or silicon tetrafluoride, and optionally also containing complex metal fluorides, to produce an ultrapure hydrofluoric acid, comprising the steps of (a) adjusting the pH of the solution to an alkaline pH to hydrolyze the fluorosilicic acid and any complex metal fluorides; (b) removing the fluoride ions and other anions from the solution by passing the solution through an ion exchange resin, where the ion exchange resin is adapted to adsorb substantially all of the fluoride passed over the ion exchange resin; (c) displacing the fluoride ions and other anions bound to the ion exchange resin, thereby forming a mixture of anions in an effluent emanating from resin; (d) optionally concentrating the effluent at a high pH and then lowering the pH; and

Abstract: A process and apparatus for separating tritium from an aqueous solution that contains one or more additional dissolved radionuclides is disclosed. In accordance with the process the aqueous solution as a first liquid phase is contacted with each of three layers as a solid phase within a column. A first layer comprises particles having a plurality of pendent methylene diphosphonate groups. A second layer comprises strongly basic anion exchange particles, and a third layer comprises polymer particles free of ionically charged groups. The contact is maintained until a second liquid phase is formed that contains tritium as substantially the only radionuclide, and that second liquid phase is collected and can then be counted to determine the amount of tritium present. The column with its three layers constitutes the separation apparatus.

Abstract: The invention relates to a method and apparatus for purifying and maintaining the purity of water in a swimming pool by initially feeding into the pool water treated in an ion exchanger to render it acidic and hardness-free, lime water consisting of a clear and saturated aqueous solution of white lime or white lime hydrate being thereafter added to provide a lime-carbonic acid equilibrium, at least some of the acidic and hardness-free water being recirculated over a body of crushed limestone to establish a pH of not less than 7. Carbon dioxide and oxygen may also be added.

Abstract: Particles that move at low Reynolds numbers are separated from a filter material on which they are adsorbed by subjecting the filter material, in a liquid medium, to agitation of sufficient magnitude to create turbulence and shear forces acting on the filter material such that the particles become desorbed from the filter material and become suspended in the liquid medium. The method may be used to recover biological particles, such as leucocytes and blood platelets, from filter materials on which they are retained by adsorption. The recovered particles may then be used in diagnostic testing and analytical techniques.

Abstract: An insert for a storm drain or sanitary sewer inlet such as are found in factory or warehouse floors, parking lots and car washes in which the insert holds one or more bags of filter media. The bags have a very open structure such as coarse weave cotton permitting water entering the drain to pass through each bag and the filter media inside the bag. The entire bag may be conveniently withdrawn from the insert and replaced as the filter media becomes saturated. Preferably, a first bag contains an absorbant cellulose particulate media which absorbs oils and greases and post non-volatile hydrocarbons and a second bag contains specially textured activated carbon which absorbs organically bound heavy metals and volatile hydrocarbons as well other VOCs (volatile organic compounds). Various types of filter media and configurations of these media also allows for the removal of dissolved heavy metals, and even the removal of pathogenic microbes.

Abstract: The object of the invention is a process for treating, in particular softening water by ion exchange in a regenerable medium, with exhaustion of the medium being measure in a bypass provided parallel to the main flow of the medium to the water sampling point and a suitable system in which the bypass line includes a measuring cell. It is therefore the aim of the invention to secure a flow through the measuring cell irrespective of that of the medium. In order to achieve this aim, control of the main flow and a suitable increase of the pressure gradient in the bypass, irrespective of the flow, is effected by means of a control unit (40), increasing the pressure reduction in the measuring cell irrespective of the flow. The throttling of the main flow results in a relative reduction of the bypass resistance and therefore all increased flow to the measuring cell.

Abstract: A waste water stream containing a heavy metal such as chromium, zinc, copper, and the like is directed from a source after pH adjustment to a tank containing adsorption material in the form of granular activated carbon. A waste water stream is directed to the tank in either an upward or downward flow mode. The heavy metal is adsorbed onto the surface of the adsorption material which is pretreated to an initial pH in the range between about 1.5 to 2.5. The water stream free of the metal contaminant is directed to an effluent tank for safe discharge. Thereafter a stripping solution preferably containing sulfuric acid is circulated through the tank to remove the adsorbed metal for the adsorption material. The metal is carried by the stripping solution from the tank to an electrolytic metal recovery unit. The unit includes a cathode terminal and the stripping solution passes through a voltage potential resulting in electrolytic deposit of the heavy metal onto the cathode terminal.

Abstract: An improved ion exchange process for purifying and/or concentrating hydroxylamine from an aqueous solution comprising hydroxylammonium ion and counter anions wherein ion exchange process conditions including effluent pH, effluent conductivity, and ion exchange bed height can be monitored and used to identify when to switch from an ion exchange step feed to a water wash feed, and to switch from a desorbent step to a water rinse step.

Abstract: A waste-water treatment device that includes a coalescing plate separator (CPS) for receiving waste-water and for specific gravity separation of hydrocarbon fluids and particles having a lower specific gravity than water from the waste-water. The CPS includes a series of plates having holes formed in ridges, where the hydrocarbon fluids rise through the holes to the surface of the waste-water in the CPS. A skimmer skims off the hydrocarbon fluids from the surface of the waste-water in the CPS and stores these fluids in an oil/product recovery tank. A particle filter receives the waste-water from the CPS and filters out suspended solids from the waste-water. A granulated activated carbon filter receives the waste-water from the particle filter and removes organic hydrocarbons from the waste-water.

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 system automated for providing at least periodic removal of metal ions and contaminants from a chemical bath, consists of a microprocessor programmed for controlling fluid circuits of pumps and valves, for in one state of operation circulating a first predetermined quantity of the chemical bath from a first tank, through an ion exchange column, and back to the first tank; for in a second state of operation circulating deionized water from a second tank into the IEX column for displacing residual chemical bath therefrom for return to the first tank; for in a third state of operation circulating deionized water through the IEX column, and discharging the rinse water from a waste port; for in a fourth state of operation circulating regenerant acid through the ion exchange column, and discharging the used acid from a waste port; for in a fifth state of operation circulating deionized water through the IEX column for rinsing acid regenerant therefrom and discharging the same out of a waste port; and for in a six

Abstract: A water softening system is provided in which a determination is made whether the slow rinse cycle of a regeneration has been completed or is abnormal. A reference cell and a spaced sensing cell are provided in a water tank. The impedance difference of the solution between the reference cell and the sensor cell is sensed. If the impedance difference is a first state, then after a predetermined period of time a determination is made if the impedance difference is a second state. If the impedance difference is a second state, then after a predetermined period of time a determination is made if the impedance difference is a third state. If the impedance difference is a third state, this indicates that the sodium ion concentration is uniformly reduced in the zone between the reference cell and the sensing cell and that the slow rinse cycle has been completed.

Abstract: A process for the treatment of waste material is disclosed. The process includes the steps of combining waste material with a treatment composition to form crystal growth structures, and adsorbing the waste material within the crystal growth structures, thereby stabilizing the waste material. The treatment composition includes natural zeolite seed, crystalline quartz, aluminum trihydrate, sodium carbonate or sodium hydroxide, and optionally dolomitic calcium oxide or calcium oxide or dolomitic limestone, and potassium hydroxide or potassium carbonate.

Abstract: A system for remediating groundwater contaminated with radionuclides, consisting of an underground bed of crushed zeolites. Distribution pipes convey contaminated groundwater to the zeolite bed by means of a pump, which draws the contaminated water through wells from an underground plume of released waste mixed with groundwater. The radionuclides in the water undergo ion exchange with the zeolite minerals, and lock into the zeolite crystal lattice. After the contaminated water passes through the zeolite bed, it is collected by a series of collection pipes and conveyed to a sampling station, where it can be determined whether the water has been decontaminated sufficiently to discharge it by piping to a river outfall or back to the ground. When functioning, the system contains the released contaminants on the waste site and prevents further spread and migration of the contaminated water by means of the cone of depression created by the pumping well.

Abstract: The present invention is directed to an analytic method for detecting trace elements in fluid solution. A cation exchange resin is packed with a radiolabelled exchange material having certain characteristics and replaces the trace element ions in the fluid which becomes labelled. The label is subsequently detected using sensitive and well known radiation detection methods.

Abstract: A method and apparatus for removing contaminants such as heavy metals and organic pollutants from contaminated water using waste cast steel shot blast fines is described. Shot blast fines were hitherto disposed of by the iron processors at significant cost. In another embodiment, waste shot blast fines are used to fix heavy metal and organic contaminants in groundwater and water runoff from contaminated landfills and industrial sites.

Abstract: The present process is designed for removing elemental iodine and iodide ions from an aqueous solution containing iodine and iodide ions. This process employees a strong-base anion exchange resin. The resin comprises trialkyl amine groups each preferably comprising from alkyl groups containing 3 to 8 carbon atoms. The aqueous solution containing elemental iodine and iodide ions is passed through the resin and thereby treats the aqueous solution by removing elemental iodine and iodide ions therefrom. The volume of the aqueous solution passing through the resin until reaching the Breakthrough Point is at least about 8 liters per cubic centimeter.

Abstract: In a water treatment process using ozone, to prevent bromate formation a quantity of bromide-containing water for treatment is first set to a pH value of less than 6.5 by feeding in CO.sub.2, unless the water already contains the requisite CO.sub.2 by origin. CO.sub.2 and ozone are then simultaneously fed in for a period of several minutes. The feed stream of CO.sub.2 is designed to maintain the pH value, and sufficient ozone is fed to the quantity of water to produce oxidation and sterilization.

Abstract: In the process for purifying an aqueous MDEA-solution the formate content of the MDEA-solution circulated in a main stream between the absorber and desorber of a hydrogen sulfide wash unit for gas produced by gasification of a carbonaceous material, e.g. coal, is measured. A partial stream of MDEA-solution is withdrawn from the main stream, passed over an ion exchange medium which removes some formate present to form a partially purified partial stream and subsequently the purified partial stream is returned to the main stream. The amount of the withdrawal from the main stream is controlled so that the formate content of the main stream is maintained between 10 and 30 g/l. Only from 0.5 to 0.08% by volume need be withdrawn from the main stream to form the partial stream. The ion exchange medium can be regenerated with a hydroxide-containing solution, which is subsequently fed to an ammonia separator column of a hydrogen sulfide wash apparatus.

Abstract: A multicomponent mixture is separated into its components by subjecting the multicomponent mixture to a separation means to flow therein, which means comprises a plurality of columns divided into at least three groups wherein each group of columns has the columns which are in the same number as that of the components in the multicomponent mixture and are filled with a adsorbent so that one column has an adsorbent specific to either one of the components; wherein the three groups are respectively assigned to fractionation in a fractionation zone, to purification in a purification zone and to desorption in a desorption zone; the groups of columns are switched from zone to zone; and the effluent from the columns used in the fractionation zone is sent to the columns in the purification zone which have once been used in the fractionation zone and the columns in the purification zone are then assigned, upon the switching, to desorption.

Abstract: An ion chromatography method for analysis of a plurality of analyte ions in a sequence of samples in which ion chromatography is performed on a sample, which is passed to a non-precipitating suppressor ion exchange resin and analyzed, the suppressor being regenerated in one step prior to processing of a subsequent sample.

Abstract: A head flush apparatus for a pressure vessel uses an equalization chamber that channels the fluid generated by the head flush into a low volume chamber and withdraws fluid from the pressure vessel through the low volume chamber. Withdrawing fluid generated by the head flush and channeling the fluid through the low volume chamber reduces or eliminates the circulation of fluid between the equalization chamber and the adjacent process chamber and minimizes the amount of contamination that can result from any circulation of fluid resulting from pressure fluctuations. The withdrawal of fluid through the low volume chamber also provides a non-contaminating path for withdrawing leakage from the vessel.

Abstract: There is disclosed a method for determining an endotoxin by reacting the endotoxin adsorbed on an adsorbent having specific endotoxin adsorbability with an endotoxin detecting reagent, including the steps of:(a) preparing a column having a tip opening, a rear end opening and an adsorbent-filling and holding means provided in the column through which a sample solution can pass,(b) introducing the endotoxin adsorbent into the column through the tip opening to fill and hold the adsorbent therein,(c) introducing the sample solution into the column through the tip opening and discharging the introduced sample solution through the rear end opening to contact the sample and the adsorbent and thereby adsorbing the endotoxin on the adsorbent, and(d) reacting the detecting reagent with the endotoxin adsorbed on the adsorbent.There is also disclosed an apparatus for the above method.

Abstract: A method and apparatus using suppression of eluents for the analysis of anions or cations in ion chromatography. The invention relates to the intermittent use of the electric field during electrochemical suppression to minimize background noise during detection of the ionic species caused by the application of an electric field using an electrolytic membrane suppressor. Using this intermittent electrochemical suppression system allows the detection of the analyte in the absence of the electric field. The system finds particular benefit in reducing background noise created during electrochemical suppression, and in reducing the baseline interference when analyzing organic solvent-containing samples.

Abstract: A method for ultra-analysis of water for trace impurities. An effective trapping media functions by binding gels that carry ultratrace analytes on their surfaces.

Abstract: A control system for a water softener, control device therefor and methods of making the same are provided, the system comprising a microcontroller operatively interconnected to an output of a comparator to effect a subsequent operation of a recycling unit for the water softener when the output signal is at a certain condition thereof, the system causing the output signal to have a phase shift relative to the phase of an A.C. power supply of the system when a sensing electrode unit in the ion exchange bed of the water softener is at a certain resistance value relative to the resistance value of a reference electrode unit that is also disposed in the ion exchange bed, the phase shift comprising the certain condition of the output signal, the microcontroller determining the certain condition by comparing the phase of the output signal to the certain phase.

Abstract: A process of continuously controlling at least one characteristic of a simulated moving bed para-xylene separation process has been developed. The characteristics controlled may be the purity or the recovery of the para-xylene. The process involves measuring the concentrations of the para-xylene, meta-xylene, ortho-xylene, and ethylbenzene in the pumparound or pusharound stream, calculating the value of the characteristic, and making required adjustments to operating variables according to an algorithm which relates changes in the value of the characteristic to the changes in the concentrations of the components resulting from changes in the operating variables. The process is unique in that the necessary quantity of data to control the separation is rapidly generated, thereby providing increased efficiency, precision, and accuracy.

Abstract: In an ion exchange treatment method for producing or regenerating an aqueous EDM fluid to be used for electric discharge machining, raw water is supplied under pressure to a column (4) charged with ion-exchange resins, and passed through a resin phase in the column (4), at a conspicuously large space velocity, for example, at least 20 h.sup.-1. Thereby, "harmful ions" to electric discharge machining are preferentially and selectively removed without excessively reducing electric conductivity of treated water at the outlet of the resin phase. The raw water is circulated through the resin phase, with the ion exchange treatment including such a large space velocity, until overall electric conductivity of treated water in a storage tank (17) is reduced to a desire value. The raw water is prevented from excessive ion exchange treatment to increase the volume of treated water per unit volume of resins, resulting in the longer useful life of resins.