IDENTIFYING AND FIGHTING INHIBITION OF NITRIFICATION AT ORESUNDSVERKET

After extension of Oresundsverket in Helsingborg severe nitrification problems have occurred, Complete inhibition of nitrification has been recognized once and a general reduction of nitrification capacity has been found compared to design, to other Swedish treatment plants and t o internationally accepted design criteria. A comprehensive examinatio n of inhibition of nitrification has identified industrial sources as the dominating contributors. Some industries have been identified as i mportant sources but fighting inhibition of nitrification requires mor e than tracking down a few dominating industries, since examination sh ows that discharges of inhibitory substances are widespread among the industries in the catchment area. Naturally, fighting inhibition of ni trification requires the elimination of contributions from industries with identified discharge, Furthermore information campaigns directed towards the industries in general are required and finally it is neces sary to include requirements for inhibitory substances in the industri al discharge permits. Copyright (C) 1996 IAWQ. Published by Elsevier S cience Ltd.