Ultrafiltration of a waste emulsified cutting oil using organic membranes

The influence of operating conditions on permeate flux was investigated usi ng organic ultrafiltration membranes to treat a synthetic cutting-oil emuls ion containing 0.05 to 0.8 wt. % oil. A commercial cutting oil, Alba-Kool, and four organic ultrafiltration membranes, two made of polysulfone (PM10 a nd PM30) and the other two of regenerated cellulose (YM10 and YM30), with c ut-off sizes of 10 000 or 30 000 Dalton, were used. All experiments were pe rformed in a commercially available stirred ultrafiltration cell. Within th e range of operating conditions studied, it was found that the highest flux es were obtained at the following conditions: crossflow velocity (rotation speed) of 375 rpm, temperature of 40 degreesC and transmembrane pressure of 0.1-0.15 MPa. Oil rejections between 99 and 99.9% were obtained. Complete membrane regeneration was achieved with a 2 vol. % aqueous solution of a co mmercial cleaning agent (Derquim+, Panreac).