Biological treatment of organically contaminated aq. liq. - using biomass filtration and composting system modified by addn. of anaerobic fixed filter reducing molecular nitrogen

摘要

In biological treatment of aq. liqs. contaminated with organic materials and having a high nitrogen content, the water passing through a biomass filter body acting as an aerobic region, and from whose outlet the treated water is taken, is in addition passed through an anaerobic region contg. sessile microorganisms, in which its nitrogenous content is converted into molecular nitrogen. This conversion may also take place under aerobic conditions. The anaerobic region consists of a fixed filter bed arranged upstream of the aerobic biomass filter body, and a part of the water leaving the outlet of this filter body is recirculated to the inlet of the anaerobic region. The suspended solids content of the raw water and microbiologically produced sludges are retained in the biomass filter body. A number of biomass filter bodies operating in series may be used. The water may be stored in a holding vessel, in which any sludge is retained, after leaving the biomass filter body. USE/ADVANTAGE - Used in the treatment of waste waters having a high nitrogen content, and at the same time producing a biomass compost suitable for use as a fertiliser. The used biomass from the biomass filter bodies is removed and preserved for future use as fertiliser, and this invention allows a purified water and a suitable fertiliser material to be produced while treating waters which are heavily contaminated with nitrogen compounds.