关键词: 渤海湾, 预处理, 超滤, 混凝, 污染

Abstract: The ultrafiltration(UF) pretreatment process is widely employed in reverse osmosis desalination project at Bohai gulf. Most researches focus on the improvements of UF membrane material, performances and the operation optimization of membrane module. But the pretreatment of UF is not widely studied. This experiment studied the effects of pretreatment to seawater by direct ultrafiltration process and coagulation/UF process. The submerged UF membrane specific flow(SF), water quality, membrane pore size distribution, the recovery rate of membrane SF, and the pollution of membrane surface were investigated for these two technologies. The results showed that both processes could achieve less than 2.0 SDI₁₅;the coagulation/UF process could significantly decrease the number of granules in seawater, thus reducing the probability of pollutants deposition and adsorption in membrane surface and improving the fouling extent of UF membrane. When the coagulation/UF process was adopted, the cake layer of membrane surface was more porous, the variation of membrane pore size distribution was insignificant, the attenuation of UF membrane SF was slowed, and the recovery rate of UF membrane SF was enhanced.

Key words: Bohai gulf, pretreatment, ultrafiltration, coagulation, pollution