The application of nanofiltration in the purification of drinking water
飲用水的污染問題愈來愈受到人們的關注，美、歐、日等發達國家都有改善水質的計劃,，如日本的MAC -2 l計劃和新MAC - 21 計劃, 將膜技術作為水凈化的有效手段。歐、美等國也支持了許多膜法(NF)水凈化試驗, 效果明顯。地下水或地表水中的污染物質主要是分子質量為殺蟲劑、除草劑以及因消毒而造成的過量有機鹵化物, 它們都是有毒甚至是致癌的。納濾膜分離法可去除消毒的副產物、痕量的除草劑、殺蟲劑、重金屬、天然有機物及部分硬度、SO2 -4 和NO -3 等, 因而是一個技術和經濟可行、可望替代傳統活性炭吸附分離法的適宜方法。
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.
一般的過程為 :進水→預處理(絮凝、過濾等)→MF(UF)→NF→出水(備用)。其優點是水質好且穩定, 化學藥劑用量少, 占地少, 節能, 省勞力,易管理和維修, 基本上可零排放。利用NF膜去除水中農藥, 大部分農藥的脫除率均可達到99%以上, 如:阿特拉津(A trazine)、苯他松(Bzntazone)、敵敵畏(D ichlorvcs)、敵草隆(D iuron)等。目前在法國巴黎市郊的一座產水量達140000m3 /d的納濾膜生產飲用水的水廠, 已成功運轉2年多, 其出水完全能滿足歐共體新近頒布的有關消毒副產物的指標要求, 出水有機碳(TOC )低于0. 2mg /L ～ 0. 3mg /L, 生物穩定性好, 能有效地防止輸水管網中細菌的繁殖。我國李靈芝等采用納濾膜循環工藝以污染嚴重的淮河水為源水進行深度處理試驗,結果表明, 該工藝可以有效去除水中的NH+4 、N、N 0-2、TOC、致突變物等雜質, 獲得安全、合格的飲用水。
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.