Water--Purification--Ion exchange process

found: Electro-coagulation and electro-oxidation in water and wastewater treatment, 2022:ECIP galley section 1.5.2 (example phrase: "Sulphate ions can be oxidized into per-sulphate (H2S2O8), whereas dissolved oxygen can be electrochemically reduced at the cathode into hydrogen peroxide (H2O2)") (DLC)2021055826

found: Wikipedia, viewed January 5, 2022(Ion exchange is a reversible interchange of one kind of ion present on an insoluble solid with another of like charge present in a solution surrounding the solid with the reaction being used especially for softening or making water demineralised, the purification of chemicals and separation of substances)

found: The Columbia Viking desk encyclopedia, 1966(under ion: to explain the fact that some substances conduct current only in aqueous solution, S.A. Arrhenius advanced the theory (1887) that molecules dissociate and parts conduct)