Abstract: Disclosed is a method for controlling the amount of leakage of per- and polyfluoroalkyl substances (PFAS) or other contaminants from resin beds during water purification processes that employ multiple vessels or banks of PFAS ad/ab-sorbing material such as ion exchange resins. The method comprises: providing at least two vessels (or at least two banks of vessels), each vessel containing a resin bed; and simultaneously passing the water source through the vessels in parallel. At start up and for a pre-determined period of time, the specific flow rates for passing the water source through the resin beds in the vessels (or banks of vessels) differ by at least 5%, preferably by at least 10%, more preferably at least 15%, and/or the volumes of resin beds in the vessels differ by at least 5%, preferably at least 10%, more preferably at least 15%.

Abstract: The present invention relates generally to regeneration of ion exchange resins and more particularly to regeneration using low concentrations of brine to remove organic contaminants from the resin.

Abstract: This application relates generally to a process for regeneration of anion exchange resins and more particularly to regeneration using inorganic fertilizer solutions (e.g., solutions of magnesium, calcium, potassium, and ammonium salts) to remove nitrate and other contaminants from the anion exchange resins.

Abstract: The present invention provides a new water purification method and system using reverse osmosis. In particular, the present invention provides methods and water purification systems using an ion exchange resin and absorbent media for pretreatment of water being fed to a reverse osmosis treatment system, where the pretreatment reduces fouling of, or deposits or chemical attack on the membrane surfaces and passageways. Particularly, a macroporous resin having an average pore diameter in the range of 1,000 to 500,000 Angstroms and a crush strength or Chatillon value of at least 24 g/bead (710 ?m bead diameter) is used.

Abstract: A new process for ion exchange softening of water used in Once-Through Steam Generators (OTSGs) by recovering and using the salt content of the blowdown water from the OTSG to regenerate the softener resin is provided, thus eliminating the cost for commercial regenerant salt that would otherwise be needed. Further, the very high purity of the salt recovered in the blowdown inherently results in the production of softened water with hardness leakage levels that are an order of magnitude lower than can be attained using commercial salt, thus reducing scale deposit potential and improving operating efficiency and reliability of the OTSG.

Abstract: The present invention provides a method for purifying or softening water comprising: passing a specific volume of feedwater through at least one service column comprising a strong acid cationic exchange resin capable of binding divalent cations that are present in the feedwater, wherein the loading of the divalent cations on the resin is restricted to about 1 to 25% of the available ion exchange sites on the resin, and the total dissolved solids in the feedwater is greater than 100 mg/l; feeding the water exiting the service column to a reverse osmosis membrane or a nanofiltration membrane to produce permeate water stream and a reject water stream; and passing all or some of the volume of the reject stream corresponding the specific volume of feedwater through at least one off-line column capable of binding monovalent cations; wherein the chemical equivalent ratio of monovalent to divalent cations in the water exiting the service column is greater than 20 to 1; wherein no external source of regenerant salt is

Abstract: The invention consists of a water treatment process using selective and regenerable weak base anion exchange resins to remove any number of complex anions, especially oxyanions including perchlorate, nitrate, chlorate, arsenate, selenate, and chromate, from aqueous solutions. The treatment process is comprised of three key processes including 1) pretreatment to lower pH, 2) ion exchange, and 3) post treatment to adjust pH and alkalinity. The invention also includes processes for regenerating weak base anion resins and treatment of the residuals generated. This invention employs pressurized treatment, carbon dioxide management, and reuse of regenerating solution to minimize pumping and treatment costs.

Abstract: A new process for ion exchange softening of water used in Once-Through Steam Generators (OTSGs) by recovering and using the salt content of the blowdown water from the OTSG to regenerate the softener resin is provided, thus eliminating the cost for commercial regenerant salt that would otherwise be needed. Further, the very high purity of the salt recovered in the blowdown inherently results in the production of softened water with hardness leakage levels that are an order of magnitude lower than can be attained using commercial salt, thus reducing scale deposit potential and improving operating efficiency and reliability of the OTSG.

Abstract: The present invention provides a new water purification method and system using reverse osmosis. In particular, the present invention provides methods and water purification systems using an ion exchange resin and absorbent media for pretreatment of water being fed to a reverse osmosis treatment system, where the pretreatment reduces fouling of, or deposits or chemical attack on the membrane surfaces and passageways. Particularly, a macroporous resin having an average pore diameter in the range of 1,000 to 500,000 Angstroms and a crush strength or Chatillon value of at least 24 g/bead (710 ?m bead diameter) is used.

Abstract: The invention consists of a water treatment process using selective and regenerable weak base anion exchange resins to remove any number of complex anions, especially oxyanions including perchlorate, nitrate, chlorate, arsenate, selenate, and chromate, from aqueous solutions. The treatment process is comprised of three key processes including 1) pretreatment to lower pH, 2) ion exchange, and 3) post treatment to adjust pH and alkalinity. The invention also includes processes for regenerating weak base anion resins and treatment of the residuals generated. This invention employs pressurized treatment, carbon dioxide management, and reuse of regenerating solution to minimize pumping and treatment costs.

Abstract: Water is treated by an ion exchange process that removes toxic ions, but does not significantly change the non-toxic ion concentration.