The macroporous matrix and special ion exchange group functionality imparts ideal nitrate selectivity to Purolite A520E making this resin particularly suitable for nitrate removal even when moderate to high concentrations of sulphate are present. Hence this resin gives superior performance in nitrate removal applications when compared with standard exchange resins. A requirement of the nitrate removal process is to produce potable water meeting the quality standard defined by the European Economic Community in the Directive No. 80/778 of July 1980. This directive limits the nitrates to a maximum admissable concentration (M.A.C.) of 50 mg NO3/l. The U.S.A. drinking water regulations limit nitrates to 10 mg NO3/l.
