纳滤工艺深度净化微污染水源水厂出水中试研究

Advanced Purification of Effluent from Micro-polluted Source Water Waterworks by Nanofiltration

为提高出水水质、保障饮用水安全,探索常规+纳滤复合工艺在微污染水源水处理中的应用,通过中试研究该复合工艺对常规工艺出水水质的提升效果,并对微污染物截留特性进行了综合评价。结果表明,纳滤深度处理工艺可显著提高对DOC、CODMn、UV254和荧光性有机物的去除效果,同时将出水浊度和颗粒数降至很低的水平。经纳滤处理后,可吸附有机卤化物、可同化有机碳和消毒副产物前驱物的浓度降低了80%以上,大大降低了消毒副产物生成量。经检测,微污染水源水厂滤后水中存在微量的多环芳烃和内分泌干扰物,由于检测出的多环芳烃多以疏水性小分子有机物为主,纳滤截留率仅在50%左右,而内分泌干扰物则以分子质量较大的溶解性有机物为主,大于纳滤膜膜孔,因而截留率可保持在95%以上。纳滤净化出水水质良好,充分保障了出水的化学安全性和生物安全性,因此可作为一种高效的微污染水源水深度处理技术。

A conventional water treatment process combined with nanofiltration (NF) membrane advanced treatment process was applied in the treatment of micro-polluted source water to improve effluent quality and ensure drinking water safety. The treatment effect of the hybrid system was studied in a pilot test,and the interception characteristics of micro-pollutants were comprehensively evaluated. The results showed that NF advanced treatment process could significantly improve the removal efficiency of DOC,CODMn,UV254 and fluorescent organic matters,which was also capable to reduce the turbidity and particle counts in effluent to a very low level. After NF purification,the concentrations of absorbable organic halogens (AOX),assimilable organic carbon (AOC) and disinfection by-product precursors were reduced by more than 80%,which greatly reduced the generation of disinfection by-products (DBPs). A small amount of polycyclic aromatic hydrocarbons (PAHs) and endocrine disruptors (EDCs) were detected in the filtered water. Since the detected PAHs were mainly hydrophobic small molecular organic substances,the rejection rate of the PAHs was only about 50%. Meanwhile,the EDCs were mainly composed of dissolved organic substances with larger molecular weight,whose molecular weights were larger than the nanofiltration membrane pores. Therefore,the rejection rate of EDCs remained above 95%. NF membrane produced high quality effluent,which fully guaranteed the chemical safety and biological safety of the effluent. Thus,it could be used as an efficient advanced treatment technology for the treatment of micro-polluted source water.