Combined Filter Pressing and Thermal Vacuum Drying of Digested Sludge in Existing Chamber Filter Presses for Mass Reduction and Hygienization

摘要

This paper present the state of the art of thermal vacuum drying in chamber filter presses for unattended automatic operation. The achieved results are exemplified by the treatment of the two stage digested combined primary,chemical and biological sludge created by the VEAS concept for nutrient removal from municipal waste water at VEAS. The water removal rate in each stage of the drying process is described,with comments on the low energy needs. The hygienisation potential of the process is demonstrated by the effect on thermostable coliforms,salmonella,the seeds of the weed,wild oat,Avena fatua, and the parasite eggs of the potato cyst nematode,Globodera rostochiensis.