Process and plant for the stabilisation and sanitisation of sewage sludge

摘要

A process and plant for stabilisation and sanitisation composed of a thermophilic and a downstream mesophilic digestion stage has a first heat exchanger in which the fresh sludge is preheated. In a second heat exchanger, upstream or downstream of admixture of thermophilic inoculation sludge, the fresh sludge or the mixture is heated to about the temperature of the thermophilic digestion chamber. In the thermophilic digestion vessel, anaerobic partial degradation of the organic constituents and simultaneously a sanitisation take place. The sludge thus treated is subjected to intermediate storage for a short time in a reservoir vessel, cooled in the first heat exchanger and transported into the mesophilic digestion stage. IMAGE