短流程超滤工艺处理东江水中试研究

Pilot Study on Short-flow Ultrafiltration Processes for Treatment of Dongjiang River Water

超滤在饮用水处理工程中的应用还存在流程长和净水功能发挥不充分等问题,导致运行费难以降低,限制了其推广应用。为此,通过构建直接超滤、微絮凝/超滤和混凝/沉淀/超滤三种短流程超滤工艺,并结合低通量运行技术进行中试研究,考察了各工艺的除污效能和运行稳定性。研究结果表明:三种短流程工艺对东江源水均能取得良好的处理效果,其中混凝/沉淀/超滤工艺对有机物的去除效果最好,微絮凝/超滤和混凝/沉淀/超滤能够稳定去除氨氮,而直接超滤则受到运行阶段的影响,三者在去除浊度上无明显差异;直接超滤和微絮凝/超滤工艺在低通量下运行时,污染缓慢且未见不可逆污染,但直接超滤工艺受原水水质影响较大,混凝/沉淀/超滤工艺能够在较高通量下低污染运行,但污染的可逆性较差,且投药量控制不佳时会导致污染速率显著增加;腐殖酸、富里酸和蛋白质类有机物均会引起膜的不可逆污染。

There still exist some problems in the application of uhrafihration （UF） in water treat- ment, such as long pretreatment process and insufficient utilization of membrane purification function. These problems would increase the running cost and thus limit the application of UF. In this study, com- parable pilot experiments of three short UF-based water treatment processes, including direct UF, micro- flocculationfUF and coagulation-sedimentation/UF, were performed to examine the pollutant removal per- formanee and running stability. The results showed that all the processes exhibited good performance in turbidity removal and the coagulation-sedimentatiort/UF process led to the best removal effect of organic matter. As far as ammonia removal is concerned, both micro-flocculation/UF and coagulation-sedimenta- tion/UF performed better than the direct UF. In terms of membrane fouling, both direct UF and micro- flocculation/UF, which operated under low flux, showed very minor flux decline, but the direct UF was vulnerable to raw water quality. The regular coagulation-sedimentation pretreatment could allow UF work- ing under a higher flux, but the fouling reversibility could be relatively worse, especially when the incor- rect coagulant dose was applied. Both humic-like and protein-like substances might contribute to the foul-ing.