METHOD FOR PREPARING OF RETURN WATER WHICH CONTAINS PETROLEUM PRODUCTS Russian patent published in 1996 - IPC

FIELD: preparing of industrial return water or sewage. SUBSTANCE: return water or sewage which contains petroleum products is treated by reagent mixture. Said mixture contains sodium polyphosphate and zinc sulfate, their quantities being 5.0-50.0 mg/l and 1.0-2.0 mg/l respectively. Then flotation with the help of air is carried out, flotation reagent being used. Alkyl dioxyethylenmethyldiethyl ammonium benzosulfonate or alkyl benzyldimethyl ammonium chloride or alkoxymethyl methyldiethyl ammonium methylsulfate is used as mentioned above flotation reagent, its quantity being 0.05-0.2 mg/l. EFFECT: improves purification degree, decreases expense of flotation reagent. 1 tbl