Lake Water Treatment Using Polyurethane-Polyvinylidene Fluoride Hollow Fiber Blend Membrane and Polyvinylidene Fluoride Hollow Fiber Membrane in a Coagulation-Microfiltration Process

摘要

Polyurethane-polyvinylidene fluoride (PU-PVDF) hollow fiber blend membrane prepared by melting, spinning and drawing processes was used to treat lake water in a submerged coagulation-microfiltration (SCMF) process. This novel membrane is characterized by its elastic pore size increase with the pressure increase; therefore, the backwashing step could effectively remove the depositions stuck in membrane pores. Compared to the system using polyvinylidene fluoride (PVDF) hollow fiber membrane, the membrane anti-fouling ability was stronger in the system using PU-PVDF blend membrane, and the transmembrane pressure increased more slowly at a fixed permeate flux. Organic matters were removed comparably for both membranes during the first 3 h treatment, but those with benzene ring structures were susceptibly restricted by PU-PVDF blend membrane as the filtration went on. The turbidity removal was stable in the PU-PVDF system with an average of 97%, and was slightly higher than that in the PVDF system. The outstanding anti-fouling ability and excellent pollutant removal performance make the PU-PVDF hollow fiber blend membrane a better candidate for the SCMF process.