Process for purification of organically polluted waste waters

摘要

30-500 mu m carbon granules are mixed with the waste water. This serves as an immobiliser for bacteria, and also as a hydrocyclonic sepn. agent. After treatment, the mixture is fed to a hydrocyclone, separating most of the activated sludge and carbon from the waste water; solids are recirculated to the activated sludge vessel. Water from the hydrocyclone with residual sludge, is filtered under pressure in a thickening stage. Thickened sludge, still pumpable, is recycled back to the start. The resulting waste water is sufficiently clean to be polished by a final sand filtration. In addition to the process described, a plant is also claimed.