Biological treatment of waste water - using excess sludge as carbon source after processing by cell wall disintegration

摘要

In a plant and process for the biological purification of waste water, esp. elimination of N, the activated sludge withdrawn as excess sludge is processed to an internally available source of C and metered into the denitrification tanks for the redn. of nitrate. The activated sludge is processed by cell wall disintegration, esp. mechanically by stirring in a stirred ball mill, in a high pressure homogeniser, or in an electro-acoustic appts., or chemically by addn. of acids, alkalis or enzymes. The degree of cell disintegration is adjusted to the need for electron donors in the denitrification zone. The whole of the treated excess sludge is fed at once to the denitrification zone, or it is fed to a concentrator, esp. a gravity or centrifugal separator or a cross-flow membrane separator. ADVANTAGE - The process solves the problems of inadequate N elimination at certain times of the day, and of dealing with the activated sludge.