超滤/纳滤组合工艺的运行与优化研究

Operation and Optimization of Ultrafiltration/Nanofiltration Hybrid Membrane Process

以超滤/纳滤组合工艺深度处理钱塘江水,探讨了运行参数对该工艺出水水质的影响以及物理和化学清洗的效果。结果表明,通量的增加以及运行周期和浓水排放周期的延长均可在一定程度上提高出水水质,但同时会加剧膜污染;运行压力的增大和错流速度的增加会提高膜通量和出水水质,膜污染速率会随压力的增加而加快,随错流速度的增大而减小;而提高回收率会使出水水质变差,同时加剧了膜污染;随着运行时间的延长,物理清洗对膜通量的恢复作用逐渐降低,适时的化学清洗可有效恢复膜通量,延长膜的使用寿命。

Through advanced treatment of Qiantang River by UF/NF hybrid membrane process, the effects of operation parameters on effluent quality and the physical and/or chemical cleaning perform- anee were discussed. The experimental results showed that the increase of flux, the extension of operation cycle, and the increase of concentrated water discharge cycle all could improve the effluent quality to some extent, but membrane fouling was aggravated at the same time. With the increase of operation pres- sure and cross-flow velocity, the membrane flux and effluent quality increased. Membrane fouling was ag- gravated with the increase of operation pressure and decreased with the increase of cross-flow velocity. As recovery rate increased, the effluent quality was deteriorated and membrane fouling was accelerated. With the extension of running time, the effect of physical cleaning on the recovery of membrane flux decreased, timely chemical cleaning could recover the membrane flux effectively and prolong the working life of the membrane.