<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">ion exchange</topic></authority><related type="broader"><topic>physicochemical processes</topic></related><variant type="other"><topic>exchange, ion</topic></variant><variant type="other"><topic>ion-exchange</topic></variant> <note xml:lang="en"><![CDATA[ Reciprocal and reversible transfer of ions of the same charge between a solution and a relatively insoluble solid in contact with it. Cation exchange and anion exchange are, respectively, the exhange of positively and negatively charged ions. Ion exchange is used in such applications as kidney dialysis, water purification, and chemical analysis. ]]></note></mads>