Wastewater pretreatment method and wastewater treatment method using this pretreatment method

摘要

The present invention provides a method for sludge treatment, comprising the following steps: (1) mixing a sludge feed from a sewage biotreatment process with a first mixed liquor to obtain a second mixed liquor; (2) subjecting the second mixed liquor to an oxygen-supplying process to obtain a third mixed liquor; (3) subjecting the third mixed liquor to an anoxic process to obtain a fourth mixed liquor; (4) separating the fourth mixed liquor to obtain a supernatant liquid and a first concentrated mixed liquor; (5) discharging the supernatant liquid, and returning at least a part of the first concentrated mixed liquor as the first mixed liquor to the step (1), wherein the amount of sludge of the first concentrated mixed liquor that does not return to the step (1) is less than the amount of sludge of the sludge feed. The present invention further relates to the use of the method for sludge treatment in sewage treatment. The method for sludge treatment can achieve a long term stable run without sludge discharge.