Removing organic impurities from water, etc. - by circulating water over selective membrane having high affinity for organic substances, and circulating liq. on permeate side having same affinity

摘要

Process for removing organic substances from a liq. comprises leading the liq. over retentate side of a membrane having a selective layer with a high affinity for the organic substance(s) so that these can permeate to the other side of the membrane under a driving force, while a liq. is led over the permeate side which also has a high affinity for the organic substance(s). Pref. the membrane is an elastomeric membrane such as those described in US4553983 and made e.g. of silicone rubber, nitrile rubber, polybutadiene rubbers, chlorosulphonated polyethylene rubbers, ethylene-propylene rubbers, natural rubber, butyl rubber, neoprene, etc.. The membrane may be in the form of a composition membrane with a microporous substrate and a selective top layer. Pref. the liq. flowing on the permeate side of the membrane is an oil or an oily liq. having good compatibility with the membrane used, esp. a silicone oil or a polybutadiene, or a higher alkanol.