The functionality of the macroporous matrix and the special ion exchanger group gives Purolite A-520E an ideal nitrate separation force even in the presence of medium and high grade sulfate concentrations. For this reason, this resin provides superior performance in nitrate removal applications compared to standard ion exchange resins. The process of nitrate removal requires the production of potable water to meet the quality standard defined by the European Economic Community by the regulation 80/778 of July 1980. This regulation limits nitrates to a maximum acceptable concentration of 50 mg NO3 / l. The U.S. Drinking Water Directive limits nitrates to 45 mg NO3 / l.