膜生物反应器在某电厂城市中水回用处理中的应用

Analysis on Membrane Bioreactor Reclaimed Municipal Wastewater in a Power Plant

某电厂采用膜生物反应器(MBR)对城市中水进行处理后作为冷却塔补水。通过对MBR运行数据、出水水质以及化学清洗效果的分析表明,MBR可有效去除来水中的COD、氨氮和悬浮物。但MBR系统运行4 a后,系统出现膜比通量下降、化学清洗效率偏低等问题。膜丝能谱(EDS)和扫描电镜(SEM)分析结果表明,有机物是造成膜污堵的主导因素,膜丝表面形成了致密的凝胶污染层,膜孔堵塞、窄化现象明显。根据MBR污染物质,提出采用EDTA碱洗+HCl酸洗+Na Cl O碱洗的清洗方案,膜比通量恢复率较常规碱洗+酸洗提高约10%。但膜孔内吸附的杂质沉积时间较长,膜孔堵塞现象难以彻底恢复。

A power plant treated municipal wastewater through membrane bioreactor（MBR） process and reused effluent as industrial cooling water application. The operating data, effluent quality and chemical cleaning effect of MBR system was analyzed, which showed that MBR could efficiently remove COD, ammonia nitrogen and suspended matter. Hoever, the membrane flux recovery rate dropped and chemical cleaning efficiency decreased when MBR system operated four years. In addition, the energy spectrum（EDS） and electron microscope（SEM） analysis indicated the organic matter was the dominant factor in causing membrane fouling. The membrane surface formed compact gel pollution layer and membrane pore blockage, narrowing phenomenon was obvious. According to the pollutant of MBR, the fouled membranes were cleaned by EDTA, HCl and Na Cl O, membrane flux recovery rate increased by about 10% comparing with the conventional caustic and acid washing. But the membrane pore blockage was difficult to complete recovery because the impurities adsorbed in membrane pores for a long time.