Hollow-Fiber Nanofiltration for Treatment of a Surface Water High in NaturalOrganic Matter

摘要

The objective of this research project was to investigate the fouling of a hollow-fiber nano-filtration membrane by natural organic material (NDM) and strategies to control it. Water typical of high NOM concentrations found in eastern North Carolina water supplies was obtained from the Tar River at the intake for the City of Tarboco and studied in bench-scale filtration tests. Greater decrease in water produced was observed with feed waters that contained high NOM concentrations and with operation at low cross-flow velocity. The addition of powdered activated carbon particles to the feed stream was found to provide a small degree of water production enhancement, apparently due to an increase in effective shear at the membrane surface. Some NDM fractions that associate with the membrane surface were removed by high-velocity rinsing but most of the fouling material required use of chemical cleaner. Some residual NOM remained and produced irreversible fouling. Results indicate that NOM composition is important when estimating the performance of nanofiltration.