SAFE MANAGEMENT OF MUNICIPAL WASTEWATER AND SLUDGE BY FIXATION OF POLLUTANTS IN VERY HIGH QUALITY HEU-TYPE ZEOLITIC TUFF

Treatment of municipal wastewater of pH 8.7 with very high quality zeolitic tuff and coagulants, resulted to clear water of pH 7.1 and improved quality characteristics by 79% to 950%. The zeolitic tuff is 2% to 317% more effective than the coagulants, concerning COD, Mn, Ni, Fe, Cr, NO3- and dissolved oxygen. The municipal-zeo-sludge produced either as precipitate or by mixing the municipal sludge with zeolitic tuff is odourless and cohesive. The leaching by deionised water of municipal-sludge reached values for the quality characteristics up to 100%, while that of the municipal-zeo-sludge reached significantly lower values. The chemistry of the seepage water from the municipal-zeo-sludge proves the fixation of dangerous substances by the zeolitic tuff. The odourless and cohesive municipal-zeo-sludge, is suitable for safe deposition, since the dangerous substances are fixed on the zeolitic tuff and not leached with the rainwater, thus protecting the quality of soils, surface and ground waters.