Dewatering of sewage sludge with coal as a conditioner using thermal compression

摘要

Thermal compression is effective for solid-liquid separation of various materials. In this paper, thermal compression was applied on the dewatering of sewage sludge with coal as a filter aid. Experiments with 0.25-1 mm coal particles (0.2 kg coal/kg dry sludge solid) obtained cakes of solid content over 49%. Higher dosage of coal generated cakes with lower moisture content. The combustion behavior of the sludge cake was studied using TG/DTG analysis. The results showed that a total weight loss of 65.1% occurred from 25°C to 800°C, including two major weight loss stages corresponding to loss of moisture and volatile materials respectively.