Removal of nitrates from water by selective ion exchange

Abstract

The applicability of ion exchange on selective anion-exchange resins to the removal of nitrates from groundwater which was to serve for drinking purposes was investigated. The concentration of nitrates in the groundwater treated in the ion-exchange process, in the presence of chloride ions (50 g Cl/m) and sulfate ions (90 g SO4 /m3), varied from 15 to 30 g N/m. The velocity of water flow through the ion-exchange column ranged between 10 and 25 m/h. The exchange capacity of the resin with respect to nitrates determined in the experimental study was 0.5 val/dm. The efficiency of the ion-exchange process up to the exhaustion of the ion-exchange capacity of the resin (expressed as the ratio of the treated water volume to the resin volume) was found to vary from 200 to 400.