INFLUENCE OF THERMAL TREATMENT CONDITIONS ON ORGANIC, NITROGEN AND PHOSPHORUS RELEASE FROM WASTE ACTIVED SLUDGE

Abstract

This study is aimed to evaluate the effect of the digestion process on the ability to release organic matter, compounds of nitrogen and phosphorus from activated sludge disposed of by thermochemical method. The study investigated the influence of factors (temperature, reaction time, pH) and activated sludge concentration on the ability to release substances was evaluated through the values of COD, TN, TP. The results show that at 50oC, the release rate of COD, TN and TP is relatively low. When the temperature gradually increased to 60oC, this rate was very fast in the first 120 minutes and gradually decreased with increasing processing time. At the same treatment temperature and time and pH value, the higher the concentration of MLSS activated sludge, the more substances released. Through the process of establishing the optimal technological parameters for the sludge treatment process, the suitable condition to release organic matter and compounds of nitrogen and phosphorus from the sludge is the temperature of 60ºC, pH = 10, processing time of 120 minutes. The COD value, TN and TP concentrations of the obtained solution are respectively 1690 mg/l, 796 mg/l and 158 mg/L.