Provided are methods of removing perchlorate from water. The methods include contacting water suspected of containing perchlorate with a cationic material. The cationic material includes one or more cationic metal atoms connected by an atom or molecule into an extended structure, and a charge balancing anion. The contacting removes perchlorate (e.g., selectively), if present, from the water. Water treatment vessels, systems and facilities that find use in practicing the methods of the present disclosure are also provided.

A process for the preparation of a granulated or pelletized weak anion exchange medium from a phenol-containing organic material like peat, followed by low-temperature torrefaction of the granules to produce a high degree of physical stability of the granules at high-pH conditions, followed by chemical pretreatment of the stable granule via a hydrolysis reaction, and optionally surface treatment with acids, followed by the main chemical treatment of the hydrolyzed granule via separate aldehyde and amine reagents, or alternatively via an adduct reagent like hexamethylenetetramine is provided by this invention. The weak anion exchange medium of this invention can be used in a variety of aqueous solution treatment processes, such as wastewater treatment for removing mineral acids like H.sub.2SO.sub.4, HNO.sub.3, HCl, HBr, HF, H.sub.3PO.sub.4, HI, or formic acid from the wastewater. The resulting anion exchanger medium is particularly useful for treating wastewaters in a low-pH environment.

A system and method configured to restore ion exchange kinetic properties and purify resin is described. Degraded ion exchange kinetic properties of anion resin will eventually result in impurity slippage through resin charges. This system and method employs an acid catalyst in combination with sulfite cleaning solution to remove organic material and to protonate iron oxides for deconstruction and removal from anion resins. The cleaning solution, when applied via a cleaning vessel utilizing an eductor(s)/plenum and wedge-wire screen draw chamber, while controlling all phases of cleaning by electronic monitoring, yields complete restoration of ion exchange kinetics on usable resin. As such, the system and method provides a safe, effective, and vastly improved method for restoring anion resin kinetics and improving regeneration quality, for improved resin performance and minimizing resin replacement costs.

A system and method configured to restore ion exchange kinetic properties and purify resin is described. Degraded ion exchange kinetic properties of anion resin will eventually result in impurity slippage through resin charges. This system and method employs an acid catalyst in combination with sulfite cleaning solution to remove organic material and to protonate iron oxides for deconstruction and removal from anion resins. The cleaning solution, when applied via a cleaning vessel utilizing an eductor(s)/plenum and wedge-wire screen draw chamber, while controlling all phases of cleaning by electronic monitoring, yields complete restoration of ion exchange kinetics on usable resin. As such, the system and method provides a safe, effective, and vastly improved method for restoring anion resin kinetics and improving regeneration quality, for improved resin performance and minimizing resin replacement costs.

A sustainable system for removing and concentrating per- and polyfluoroalkyl substances (PFAS) from water. The system includes an anion exchange vessel having a selected anion exchange resin therein configured to remove PFAS from the water. A line coupled to the vessel introduces a flow of water contaminated with PFAS such that the PFAS bind to the selected anion exchange resin and are thereby removed from the water. A regenerant solution line is coupled to the anion exchange vessel to introduce an optimized regenerant solution to the anion exchange vessel to remove the PFAS from the anion exchange resin, thereby regenerating the anion exchange resin and generating a spent regenerate solution comprised of the removed PFAS and the optimized regenerant solution. A separation and recovery subsystem recovers the optimized regenerant solution for reuse and separates and concentrates the removed PFAS.

A sustainable system for removing and concentrating per- and polyfluoroalkyl substances (PFAS) from water. The system includes an anion exchange vessel having a selected anion exchange resin therein configured to remove PFAS from the water. A line coupled to the vessel introduces a flow of water contaminated with PFAS such that the PFAS bind to the selected anion exchange resin and are thereby removed from the water. A regenerant solution line is coupled to the anion exchange vessel to introduce an optimized regenerant solution to the anion exchange vessel to remove the PFAS from the anion exchange resin, thereby regenerating the anion exchange resin and generating a spent regenerate solution comprised of the removed PFAS and the optimized regenerant solution. A separation and recovery subsystem recovers the optimized regenerant solution for reuse and separates and concentrates the removed PFAS.

A sustainable system for removing and concentrating per- and polyfluoroallcyl substances (PFAS) from water. The system includes an anion exchange vessel having a selected anion exchange resin therein configured to remove PFAS from the water. A line coupled to the vessel introduces a flow of water contaminated with PFAS such that the PFAS bind to the selected anion exchange resin and are thereby removed from the water. A regenerant solution line is coupled to the anion exchange vessel to introduce an optimized regenerant solution to the anion exchange vessel to remove the PFAS from the anion exchange resin, thereby regenerating the anion exchange resin and generating a spent regenerant solution comprised of the removed PFAS and the optimized regenerant solution. A separation and recovery subsystem recovers the optimized regenerant solution for reuse and separates and concentrates the removed PFAS.

A sustainable system for removing and concentrating per- and polyfluoroallcyl substances (PFAS) from water. The system includes an anion exchange vessel having a selected anion exchange resin therein configured to remove PFAS from the water. A line coupled to the vessel introduces a flow of water contaminated with PFAS such that the PFAS bind to the selected anion exchange resin and are thereby removed from the water. A regenerant solution line is coupled to the anion exchange vessel to introduce an optimized regenerant solution to the anion exchange vessel to remove the PFAS from the anion exchange resin, thereby regenerating the anion exchange resin and generating a spent regenerant solution comprised of the removed PFAS and the optimized regenerant solution. A separation and recovery subsystem recovers the optimized regenerant solution for reuse and separates and concentrates the removed PFAS.

The present invention relates to a method of removing chromate ions from an ion-exchange effluent, the method comprising: (i) providing an ion-exchange effluent comprising chromate ions obtained from the regeneration of an ion-exchange material, (ii) admixing the ion-exchange effluent with a source of alkali metal dithionite to form a first precipitate, and (iii) removing the first precipitate

The present invention relates to a method of removing chromate ions from an ion-exchange effluent, the method comprising: (i) providing an ion-exchange effluent comprising chromate ions obtained from the regeneration of an ion-exchange material, (ii) admixing the ion-exchange effluent with a source of alkali metal dithionite to form a first precipitate, and (iii) removing the first precipitate