Effect of UF operating conditions on purification process of Acid Red

A soluble dye Acid Red was purified by a UF process.The effects of operating pressure,flux of feed solution and feed concentration on the separation process of UF membranes were studied.Two kinds of UF membranes with molecular weight cut-off value 5 000 and 10 000 respectively were selected in the experiments,and the results showed that the permeation flux and impurities rejection of two UF membranes increased with the increase of operating pressure in the range of 0.15 MPa to 0.4 MPa,while the dye rejection of two UF membranes decreased slightly at the same time.The permeation flux and impurities rejection of UF membrane MWCO 5 000 increased with the increase of feed flux in the range of 10 m3/s to 30 m3/s,while the dye rejection of UF membrane MWCO 5 000,the permeation flux,impurities and dye rejection of UF membrane MWCO 10 000 were unchangeable.The permeation flux,impurities and dye rejection of two UF membranes decreased with the increase of feed concentration in the range of 0.5% to 4%.In addition,the pore-clogging was the main factor affecting the performance of UF membrane MWCO 10 000,while the gel layer formation on the membrane surface was the main factor affecting performance of UF membrane MWCO 15 000.