Dewatering activated sludge from effluent treatment - by acidifying, heating then separating the dehydrated sludge

摘要

A process for sepg. water from secondary activated sludge comprises acidifying the sludge to a Ph 4, heating at 70-100 degrees C to rupture the biological cells by hydrolysis and force the water, then sepg. the dehydrated sludge from the water. The process is used for treating activated sludge from treatment of industrial or urban effluents. The sludge contains 95% water and the process increases the solids content by 5-10 times and the water is easily sepd. and has a low BOD. The solids may be further treated by known processes such as heating to give a prod. suitable for use as a fertiliser or for use as a protein in animal feeds.