Bio-film process for denitrification of waste water

摘要

A biological film denitrification process comprises contacting the biomass alternately with effluent water containing biodegradable organic materials, and effluent water containing nitrate. The process is effected in an assembly with two independent hydraulic zones; an enrichment and separation zone, (1) and a denitrification zone (2). These zones are arranged over each other, and each has an inlet and outlet. Each zone is differently charged, first with organically-laden effluent water (3) and then with effluent water containing nitrate (5). The assembly has a biomass system with the following features; the microorganisms form a biofilm on freely moving carrier particles which have a lower density than effluent water, through which they therefore rise; the microorganisms are introduced into the enrichment and separation zone (1) and by reason of their upthrust climb against the flow of effluent water into the denitrification zone (2); the microorganisms are removed from the denitrification zone (2) and are returned to the absorption and separation zone (1), where they again rise through the denitrification zone (2).