Integrated ion exchange/catalytic process for efficient removal of nitrates from drinking water

A nitrate removal process that drastically reduces salt consumption and waste discharge has been developed on a bench scale. Nitrate is removed by chloride ion-exchange, and the: strong-base anion resin is completely regenerated at mild reaction conditions (i.e., ambient temperature, atmospheric pressure) in a closed circuit containing a single-flow fixed-bed reactor packed with a Pd-Cu/gamma -Al2O3 catalyst. The combined treatment system avoids direct contact between the denitrification reactor and the water to be treated, and minimizes operational problems associated with each separate technique. No dissolution of Pd and Cu metallic phases was observed at the given operating conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.