The application of nanofiltration in the purification of drinking water
饮用水的污染问题愈来愈受到人们的关注，美、欧、日等发达国家都有改善水质的计划,，如日本的MAC -2 l计划和新MAC - 21 计划, 将膜技术作为水净化的有效手段。欧、美等国也支持了许多膜法(NF)水净化试验, 效果明显。地下水或地表水中的污染物质主要是分子质量为杀虫剂、除草剂以及因消毒而造成的过量有机卤化物, 它们都是有毒甚至是致癌的。纳滤膜分离法可去除消毒的副产物、痕量的除草剂、杀虫剂、重金属、天然有机物及部分硬度、SO2 -4 和NO -3 等, 因而是一个技术和经济可行、可望替代传统活性炭吸附分离法的适宜方法。
The pollution problem of drinking water has been getting more and more attention. The developed countries such as the United States, Europe and Japan have plans to improve the water quality, such as the MAC -2 l program in Japan and the new MAC - 21 plan, and use membrane technology as an effective means of water purification. Many European and American countries have also supported a lot of membrane water purification (NF) tests. Contaminants in groundwater or surface water are mainly molecular mass of pesticides, herbicides, and excessive organic halides caused by disinfection, which are both toxic and even carcinogenic. Nanofiltration membrane separation method can remove the disinfection by-products, trace herbicides, pesticides, heavy metals, natural organic compounds and partial hardness, SO2 -4 and NO -3, so it is a feasible and economical method to replace the traditional activated carbon adsorption separation method.
一般的过程为 :进水→预处理(絮凝、过滤等)→MF(UF)→NF→出水(备用)。其优点是水质好且稳定, 化学药剂用量少, 占地少, 节能, 省劳力,易管理和维修, 基本上可零排放。利用NF膜去除水中农药, 大部分农药的脱除率均可达到99%以上, 如:阿特拉津(A trazine)、苯他松(Bzntazone)、敌敌畏(D ichlorvcs)、敌草隆(D iuron)等。目前在法国巴黎市郊的一座产水量达140000m3 /d的纳滤膜生产饮用水的水厂, 已成功运转2年多, 其出水完全能满足欧共体新近颁布的有关消毒副产物的指标要求, 出水有机碳(TOC )低于0. 2mg /L ～ 0. 3mg /L, 生物稳定性好, 能有效地防止输水管网中细菌的繁殖。我国李灵芝等采用纳滤膜循环工艺以污染严重的淮河水为源水进行深度处理试验,结果表明, 该工艺可以有效去除水中的NH+4 、N、N 0-2、TOC、致突变物等杂质, 获得安全、合格的饮用水。
The general process is: influent to pretreatment (flocculation, filtration, etc.) to MF (UF) to NF to effluent (reserve). Its advantages are good and stable water quality, less chemical dosage, less land occupation, energy saving, labor saving, easy management and maintenance, and basically zero discharge. Using NF membrane to remove pesticides, most of the pesticides can be removed more than 99%, such as Atala Zin (A Trazine), benzuron (Bzntazone), dichlorvos (D ichlorvcs), and diuron (D iuron). At present, a water plant producing drinking water with a water yield of 140000m3 /d in the suburb of Paris, France, has been successfully running for more than 2 years. The effluent completely meets the requirements of the European Community's newly issued index of disinfection by-products. The effluent organic carbon (TOC) is lower than 0. 2mg /L to 0. 3mg /L, and the biological stability is good and can be effectively prevented. The propagation of bacteria in the pipeline network. Li Lingzhi, China, and so on, using the nanofiltration membrane cycle technology to treat the polluted Huaihe water as the source water, the result shows that the technology can effectively remove the impurities such as NH+4, N, N 0-2, TOC, mutageny and so on, and obtain safe and qualified drinking water.