MBR处理微污染河水中PPCPs的效能及膜污染特性研究

THE EFFICIENCY AND MEMBRANE FOULING CHARACTERISTICS OF MBR FOR REMOVING PPCPs IN THE MICRO-POLLUTED WATER

采用一体式膜生物反应器处理微污染河水中的PPCPs(邻苯二甲酸二甲酯、布洛芬、卡马西平、壬基酚)。结果表明,在平均容积负荷为0.077kg/(m.3d)、平均PPCPs的质量浓度为50μg/L、DO的质量浓度>6 mg/L、HRT为3 h、温度为25℃、不排泥的条件下,邻苯二甲酸二甲酯、布洛芬、壬基酚的去除效果最优,平均去除率分别为94.6%、97.2%、93.6%;而卡马西平去除率低于5%。膜组件膜比通量变化大致可分为初期的缓慢下降、随后的快速下降阶段和最后的缓慢下降3个阶段;膜的不可逆阻力最大,浓差极化阻力最小,分别为膜总阻力的37.18%和15.5%,即膜污染主要由长期运行过程中膜孔被细小微粒阻塞所导致;经过清水清洗后,膜比通量恢复到初始膜比通量的47.5%,而后的酸洗和碱洗使膜比通量略有恢复,最后的氧化剂清洗,使得膜比通量恢复至原来的92.5%。

A submerged membrane bioreactor was used to treat the PPCPs in the micro-polluted water （dimethyl phthalate, ibuprofen, carbamazepine and nonylphenol）. The results showed that： when the average volumetric loading was 0.077 kg/（m^3·d）, the average influent concentration of p（PPCPs）=50 μg/L, p（DO）〉 6 mg/L, HRT=3 h, SRT=∞, temperature=25 ℃, the removal of dimethyl phthalate, ibuprofen, nonylphenol were optimal, and the average removal efficiencies were 94.6%, 97.2%, 93.6% respectively. But the removal efficiency of carbamazepine in various conditions were less than 5%. The flux of membrane module showed a trend ,which could be broadly divided into three stages, namely the initial phase of slow decline, followed by the rapid decline phase and the final slow decline phase. The test of membrane fouling had shown that the irreversible resistance which accounted for 37.18% of the membrane total resistance was maximum, and the concentration polarization resistance accounted for 15.5%.of the membrane total resistance, which indicating that membrane fouling was mainly caused by the membrane pore blocking of small particles in the long-running process. The washing text show that： After water washing, the specific flux recovered to 47.5% of the initial specific flux. Pickling and alkaline cleaning recovered specific flux slightly. Oxidant cleansing recovered the specific flux to 92.5% of the initial specific flux.