Process and plant for the disposal of sewage sludge removed from a sewage treatment plant

摘要

Process for the disposal of the sludge withdrawn from a sewage treatment plant, in particular from an absorption-waste water purification plant, with production of methane-containing fermentation gas, the sewage sludge being introduced into a septic tank, heated in the septic tank with the aid of an external heat source to a controllable fermentation temperature beneath the temperature of thermophilic digestion and, with or without circulation, at a predetermined residence time, being subjected to a sludge digestion. The fermentation gas is withdrawn from the head of the septic tank, the treated sludge is removed from the bottom of the septic tank. The sewage sludge is exposed in the septic tank to the action of an electromagnetic alternating field, which produces an additional heating of the sludge. The residence time is set to a range of 5 to 20 days, preferably about 10 days. The fermentation gas production is adjusted with the aid of the heat source, and on the other hand is optimally controlled or regulated by change in the parameters of the electromagnetic alternating field.