A stack of ion exchange membranes suitable for water purification comprising a plurality of anion exchange membranes (AEMs) and a plurality of cation exchange membranes (CEMs), wherein the colour properties of the AEMs are visibly different to the colour properties of the CEMs. The invention also provides a process for making membrane stacks in which the likelihood of there being two consecutive membranes of like charge is reduced. Furthermore, it is easy to identify whether there are two consecutive membranes of like charge present in the stacks.

Disclosed herein are compositions and methods for manufacturing composite paper-based sorbents configured for durability, and high surface area exposure to air. Composite paper-based sorbents can comprise fibers (e.g. natural and/or synthetic fibers), anion exchange resins, and additives. Composite paper-based sorbents can be configured for durability when used in various forming processes, e.g., corrugation, and when used under a variety of conditions, for example, in high and low humidity environments.

Disclosed herein are compositions and methods for manufacturing composite paper-based sorbents configured for durability, and high surface area exposure to air. Composite paper-based sorbents can comprise fibers (e.g. natural and/or synthetic fibers), anion exchange resins, and additives. Composite paper-based sorbents can be configured for durability when used in various forming processes, e.g., corrugation, and when used under a variety of conditions, for example, in high and low humidity environments.

Some embodiments of the invention include inventive catalysts (e.g., catalysts of Formula (I)). Other embodiments include compositions comprising the inventive catalysts. Some embodiments include methods of using the inventive catalysts (e.g., in hydrofluorination of an organic compound). Further embodiments include methods for making the inventive catalysts. Additional embodiments of the invention are also discussed herein.

Some embodiments of the invention include inventive catalysts (e.g., catalysts of Formula (I)). Other embodiments include compositions comprising the inventive catalysts. Some embodiments include methods of using the inventive catalysts (e.g., in hydrofluorination of an organic compound). Further embodiments include methods for making the inventive catalysts. Additional embodiments of the invention are also discussed herein.

The present invention relates to a process and plant for treating feed water containing nitrate. The process includes, sorbing nitrate from the feed water onto an ion exchange resin to form a loaded resin and produce a treated water stream depleted in nitrate, regenerating the loaded resin so that the resin can be reused and produce a brine stream high in nitrate; and converting nitrate in the brine stream into molecular nitrogen gas with the assistance of a bioactive agent.

The present invention relates to a process and plant for treating feed water containing nitrate. The process includes, sorbing nitrate from the feed water onto an ion exchange resin to form a loaded resin and produce a treated water stream depleted in nitrate, regenerating the loaded resin so that the resin can be reused and produce a brine stream high in nitrate; and converting nitrate in the brine stream into molecular nitrogen gas with the assistance of a bioactive agent.

Methods, systems, and techniques for removal of PFAS contaminants from contaminated soil or sediment are provided. Example embodiments provide a water-based ex-situ method and system at a site that utilizes particle size and particle density segregation; deagglomeration, attrition, and retention time and sequential contacts with purified water; a recirculating water system with continual water treatment, and additional modules for destructive treatment of concentrated PFAS. In an example embodiment, the water treatment system of an example PFAS contaminant removal system and process includes ion exchange resin filtration component to remove PFAS effectively.

Methods, systems, and techniques for removal of PFAS contaminants from contaminated soil or sediment are provided. Example embodiments provide a water-based ex-situ method and system at a site that utilizes particle size and particle density segregation; deagglomeration, attrition, and retention time and sequential contacts with purified water; a recirculating water system with continual water treatment, and additional modules for destructive treatment of concentrated PFAS. In an example embodiment, the water treatment system of an example PFAS contaminant removal system and process includes ion exchange resin filtration component to remove PFAS effectively.

Provided are a method of removing a perchlorate ion (ClO.sub.4.sup.−) and a nitrate ion (NO.sub.3.sup.−) which are toxic anions in wastewater using an anion-exchange resin on which a metal is supported, and more particularly an anion-exchange resin on which a hydrogen activating metal is supported or a hydrogen activating metal and a secondary metal are supported together and a method of removing toxic anions using the same. The toxic anions may be efficiently ion-exchanged and removed using an anion-exchange resin supporting a reduction catalyst, the regeneration of the anion-exchange resin may be facilitated, and the consumption of energy and the reducing agent may be reduced, thereby being usable in removal of toxic anions from an actual water purification system.