Physicochemical Characteristics and TG-DSC Thermodynamics of Municipal Sewage Sludge

Abstract

The sludge yield of municipal wastewater treatment plant is increasing day by day. The physicochemical characteristics of sludge and its heat treatment characteristics are changing constantly. It is of great significance to explore environmental friendly, technical and feasible sludge treatment and disposal methods with economic benefits, so as to avoid environmental pollution caused by improper disposal of sludge. The waste sludge from a sewage treatment plant in Chongqing was selected as raw material. The physical and chemical indexes of samples and the thermodynamic characteristics of TG-DSC are studied respectively. The results showed that the heat value of sludge samples reached 8090 J/g. The TG curve consists of 3 major stages of thermal weightlessness. There are two exothermic peaks and two endothermic peaks in the DSC curve. The ignition point of sludge in an air atmosphere is 214.5 degrees centigrade. The self -sustained combustion time of the sludge is about 3 minutes. Sludge samples have the prospect of biomass energy utilization.