A pilot plant study on a polyvinylchloride hollow fiber ultrafiltration membrane process was conducted for treating surface water. The membrane system was operated in the dead-end filtration mode under different constant permeate fluxes. The results show that the optimized operation (transmembrane pressure≤0.1 MPa, filtration time≤30 min) with a hydraulic cleaning (30 s) and a chemical cleaning (30 min, the chemical cleaning was performed after 16 cycles of filtration ) ensures a quite steady flux (1 100 L/(m^2·h·MPa)) and good permeate quality (turbidity<0.1 NTU). A full-scale plant can be suggested to operate with a mixed strategy of constant permeate flux mode (transmembrane pressure≤0.1 MPa) and constant transmembrane pressure mode. When the temperature of raw water becomes below 5 ℃, a constant transmembrane pressure mode should be used; otherwise a constant permeate flux mode (transmembrane pressure≤0.1 MPa) can be operated. In this way, irreversible fouling of ultrafiltration membrane can be minimized to keep a stable flux and make the life of membrane longer.
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