The main methods of sludge dewatering in urban sewage plants are ()

After centralized treatment, the water content of sludge is still very high, generally around 95% ~ 97%, and the volume is still very large. In order to facilitate the transportation and final disposal of sludge, it is necessary to further reduce the water content of sludge, and the process of reducing the water content of sludge to below 85% is called dehydration drying. After dehydration, the volume of sludge is greatly reduced, and it has solid properties and is mud-like. The main methods of sludge dehydration are natural dehydration, sludge drying and incineration. (Note: The knowledge point of this question has been deleted in the fourth edition of the new textbook)