Method and apparatus for biologically purifying sewage which is organically loaded with substances difficult to decompose biologically or not decomposable biologically

摘要

Biologically purifying sewage which is organically loaded with substances that are difficult to decompose biologically or are not decomposable biologically has the substances that are difficult to decompose biologically or are not decomposable biologically separated and concentrated to concentrate, the concentrate preferably is treated physically and/or chemically and the treated or untreated concentrate is subjected to a biological transformation or, alternatively, the concentrate is separated from the sewage to be purified. The apparatus has a filtration collecting-basin serving for concentrating the substances that are difficult to decompose biologically or not decomposable biologically, and a membrane-filtering or nanofiltering device connected thereto, in which the substances that are difficult to decompose biologically or not decomposable biologically are retained and to which the sewage with the concentrated substances that are difficult to decompose biologically or not decomposable biologically is supplied on the inlet side, and from which the purified sewage is drawn off on the outlet side.