抄録
In recent years, the amount of excess sludge increases with the spread of sewage treatment equipment, and there need methods of reduction and recycling excess sludge. We developed hydrothermal pre-treatment that promotes anaerobic digestion of excess sludge. As a results of experiments .hydrothermal treatment and digestion, we make clear the best conditions to improve digestion, temperature 150-170℃, pressure 0.95MPa, and air supply of very small quantity. Furthermore, a result of trial calculation in case of applying to digestive process shows that hydrothermal pre-treatment reduce residue and produce electricity largely than usual, the reduction rate of sludge is above 40%, and the production rate of electricity is above 70%.
