METHOD OF REMOVING POLLUTING SUBSTANCES FROM WATER OR WET SOLID Russian patent published in 1998 - IPC

FIELD: purification techniques. SUBSTANCE: invention relates to removing undesired substance, in particular, crude oil, hydrocarbons, and paints and consists in that isocyanate-containing prepolymer with 5-10 wt % NCO groups is brought in contact with these substances to form foam entraining undesired substance followed by removing it from required material. Prepolymer is reaction product of excess amount of polymethylene-polyphenylene polyisocyanate or diphenylmethane diisocyanate with polyatomic alcohol polyether containing at least 50 wt % oxyethylene moiety, amount of prepolymer used is 5 to 200 weight parts per 100 weight parts of undesired substance. EFFECT: facilitated oil removal. 5 cl, 2 tbl