超滤工艺净化微污染原水的试验研究

Study on Ultrafiltration Process for the Treatment of Micropolluted Water

采用混凝沉淀-超滤工艺对微污染原水进行试验，对组合工艺的除污染特性进行了研究。结果表明，组合工艺对浊度、颗粒物和藻类的去除效果非常好。出水浊度稳定在0．1NTU以下，水中粒径〉2μm的颗粒数约19＋／mL，藻类平均数量约为2．2×10^4个/L。在去除有机物方面，组合工艺对高锰酸盐指数、UV254和DOC的去除率分别为38．0％、15．2％和32．碱，其中对高锰酸盐指数的去除效果较为突出，出水高锰酸盐指数浓度为2．69～2．87mg／L。组合工艺去除的有机物是分子量大于3KD的大分子有机物，对小分子有机物去除效果不明显。其中，混凝沉淀主要去除了水中的疏水性有机物和亲水荷电有机物，超滤膜去除的有机物则以亲水中性有机物为主。在工艺运行期间，超滤膜的跨膜压差增加了约12．3％，跨膜压差的升高主要由被超滤膜吸附的小分子有机物产生。

A process of coagulation/sedimentation/ultrafiltration was used for the treatment of micro-polluted source water, and the pollutants removal was investigated. Results showed that the process had a high removal efficiency for turbidity, particles and algae. The effluent turbidity was below 0.1NTU, the number of particle bigger than 21xm was about 19counts/mL, and the algae were 2.2×10^4 counts/L. In organics removal, the process reduced 38%, 15.2% and 32.6% of CODe,, UV254 and DOC respectively. It had a prominent high removal rate for CODMn, and the effluent CODMn was 2.69 -2.87mg/L. The combined process removed most organics with molecular weight of more than 3KD, and the small organics was difficult to be removed. The coagulation/sedimentation process removed most hydrophobic organics and hydrophilic polar organics, while the ultrafiltration mainly removed hydrophilic neutral organics. The trans-membrane pressure increased about 12.3% during the process operation, which was caused by the adsorption of small organics.