Biological waste water treatment, useful for treatment of, e.g. commercial waste water, comprises degradation of organic substances with microorganisms, nitrification, solids filtration and optionally phosphate degradation

摘要

Biological waste water treatment (I), comprises: (A) using a biofilter colonized with sessile microorganisms to effect degradation of organic substances, nitrification, solids filtration and optionally phosphate degradation; and (B) effecting denitrification in an anoxic activation step by recycling the biofilter effluent to any stage in the process preceding the activation step. Biological waste water treatment (I) comprising prepurification, optional preclarification, optional phosphate elimination, activation and optional postclarification steps comprises: (A) using a biofilter colonized with sessile microorganisms to effect degradation of organic substances, nitrification, solids filtration and optionally phosphate degradation; and (B) effecting denitrification in an anoxic activation step by recycling the biofilter effluent to any stage in the process preceding the activation step. An Independent claim is also included for a biological waste water treatment plant comprising: (a) mechanical prepurification equipment (12); (b) optional preclarification tanks; (c) optional phosphate elimination equipment (13); (d) one or more activation tanks (11); (e) an optional postclarification tank (14); (f) a biofilter (16); and (g) a outlet for recycling the biofilter effluent to one or more of the preceding tanks.