Process for the purification and treatment of liquids resulting from the cleaning of tank and silo road vehicles, railway tank wagons and tankers

摘要

The dirty wash effluents (1-8) from each product are combined and homogenized (39) for multi-stage biological purification treatment. Preferred Features: Supply to treatment is continuous. Chemical-physical treatment precedes multistage biological treatment. Multistage settlement is followed by after-purification. The effluents are united in day equalization tanks, serving also as homogenization tanks, from which they are supplied continuously to biological treatment. Film-biological treatment, preferably as two-stage fixed bed processes, is employed. For sludge de-watering, plate separators (42, 49, 53) are used. Membrane filtration separates biomass, removing solids, bacteria and some viruses. For filtration, e.g. multilayer filters, fabric filters or ceramic filters are used. COD elimination during bio-treatment amounts to 90% or more. Before final outfall, the cleaned water is filtered, preferably in an activated carbon filter. Up to 90% is recycled. For biological purification, the activated sludge process is used. Treatment of a variety of washing effluent types is detailed, specifying conventional additives and processes, with quantified process parameters.