PROCESS FOR TREATING A LIQUID INVOLVING CATION EXCHANGE AND SELECTIVE REMOVAL OF NITRATE IONS FROM THE LIQUID, AND ION EXCHANGE RESIN MIXTURES SUITABLE FOR USE THEREIN

摘要

PROCESS FOR TREATING A LIQUID INVOLVING CATION EXCHANGE AND SELECTIVE REMOVAL OF NITRATE IONS FROM THE LIQUID, AND ION EXCHANGE RESIN MIXTURES SUITABLE FOR USE THEREIN A process is disclosed for exchanging hardness ions and selectively removing nitrate ions from an aqueous liquid, by passing it through a cation/anion exchange resin mixture, in which (i) hardness ions are exchanged, (ii) any cations and nitrate ions present are independently removed, and (iii) the anion exchange resin is loaded with nitrate ions to at least 80% of its nitrate capacity. Initial regeneration is with a chloride salt. The Process avoids calcium precipitation during regeneration.