Patent ID: 6063206
Filing Date: 2000-05-16
Classification: C11D,C23G

Abstract:
An environmentally-friendly method for cleaning and de-oiling metal parts contaminated with oil or other organic compounds, said method comprising the steps of:1) providing a first chamber containing the metal parts;2) treating the metal parts contaminated with oil or other organic compounds with a first aqueous solution containing surfactants to remove the oil or the other organic compounds from the metal parts and thereby solubilize the oil or the other organic compounds and form a second aqueous solution containing the surfactants, and solubilized oil or the other organic compounds in the first chamber;3) removing the metal parts from the second aqueous solution;4) treating the surfactants and the solubilized oil or the other organic compounds in the second aqueous solution with a third aqueous solution containing oil-degrading enzymes to degrade the oil or the other organic compounds and form a fourth aqueous solution containing the oil-degrading enzymes, the surfactants and degraded oil or other degraded organic compounds in the first chamber;5) transferring the fourth aqueous solution to a second chamber; and6) treating the fourth aqueous solution in the second chamber with additional oil-degrading enzymes, wherein the additional oil-degrading enzymes further degrade the surfactants from the first aqueous solution and any undegraded oil or undegraded organic compounds remaining in the fourth aqueous solution;wherein the surfactants in the first aqueous solution include (a) at least two alkylphenol ethoxylates; (b) one or more alkaline metal salts of alkane sulfonic acid; and .COPYRGT. one or more alkanolamines.