CHARACTERISTICS OF THE SLUDGE FROM WASTEWATER TREATMENT PLANTS IN THE TERRITORY OF AGRICULTURAL UNIVERSITY OF TIRANA, ALBANIA

Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. On the other hand, this sludge has benefits for plants and soils. Sludge characteristics are very important for determining the right treatment, and so the wastewater characteristics. The aim of this study is to present the characteristics of the sludge, generated in inlet and in biological wastewater of pilot plant. The sludge was analyzed for physical-chemical and heavy metal indicators, contents of organic pollution, according to Council of the European Communities 1986 on the use of sludge in agricultural practices. Parameters subject to the provisions of the directive include organic matter (% dry solids), total carbon (%), pH, electrical conductivity (μS/cm), total nitrogen (% dry solids), total phosphorus (% dry solids) and heavy metal (copper, nickel, zinc, cadmium, lead, chromium (expressed in mg/kg dry solids). The results show that the sludge is biomass, rich in macro and microelements and can be used to maintain and enhance soil fertility, for recultivation of disturbed areas and others, provided that they meet the requirements of the regulations.