Sepg. oil and soiling agent contg. water from laundries - by heating and mixing with per:chloroethylene, sepg. oil and water phases by ultrafiltration and distilling to separate agent and solvent

摘要

Demixing waste water at ca. 70 deg. C obtd. from washing of clothes in large scale laundries, which besides the usual impurities derived from soiling also contains oil-in-water emulsions, comprises adding a solvent, esp. diluted perchloroethylene to the water with heating to 90 deg. C to split the waste water into a first phase consisting essentially of water with a small amt. of oil which is separated by ultrafiltration into water and disposable oil, and a second liq. phase comprising the solvent, the soiling material and oil, this phase being sepd. by distn. into a disposable oil-soiling agent mixt. and the solvent which is recycled to the demixing. USE/ADVANTAGE - The process is economical to operate, does not use consumable chemicals which find their way into the treated water, gives only small amts. of waste material to be disposed of, uses a solvent which is recycled in a closed loop, and gives treated water with a very low residual oil content.