Patent ID: 6306249
Filing Date: 2001-10-23
Classification: B01D,B01F,C02F,C08G,C11D,Y10S

Abstract:
A method for cleaning a hard surface which is contaminated with hydrophobic contaminants, comprising:(a) treating said hard surface to remove at least some of said hydrophobic contaminants by contacting said hard surface with a composition comprising an aqueous solution of a nonionic, splittable surfactant having either of, or mixtures of, the formulas ##STR7##or, ##STR8##of which R is hydrogen and R' is the residue of an organic compound (substituted or unsubstituted) derived from an aldehyde of the formula ##STR9##wherein R is hydrogen and R' is the residue of an organic compound (substituted or unsubstituted) which contains a total of about 8 to about 20 carbon atoms; X is hydrogen or the residue of a hydrophobic end-cap; Y is hydrogen, methyl, ethyl, or mixtures thereof; Z is hydrogen, methyl, or ethyl; m is 0 or 1; and n is an integer of 1 to about 40;(b) removing an effluent stream comprising the hydrophobic contaminants removed from the hard surface in step (a) in aqueous emulsion with said surfactant;(c) treating said effluent stream with an acidic material to reduce its pH sufficiently to cause the surfactant to irreversibly split into an aldehyde and a polyol, thereby causing the hydrophobic contaminants contained in the aqueous emulsion to be released from the emulsion to create a water-insoluble phase comprising the aldehyde and the hydrophobic contaminants and a relatively contaminant-free aqueous phase comprising the polyol; and(d) separating at least some of said water-insoluble phase from said aqueous phase.