Development of nanofiltration technology as a tool for concentration and partitioning of organic matters and separation of micropollutants

研究了纳滤膜和反渗透膜在地表水和地下水饮用水处理以及渗滤液处理中的截留特性。市售膜的分子量截止尺寸由醇和糖确定。一些名义脱盐率较低的膜在TOC测试中对天然有机物的截留率超过90%，有机物截留率与盐截留率之间的相关性较小。不仅地表水处理，而且地下水处理和渗滤液处理都发现这种不显著的相关性。双酚A，这被认为是一种内分泌干扰物质表现出较低的排斥比预测值从分子量的排斥关系从糖排斥。以某实际渗滤液处理设施为研究对象，采用高截留率的反渗透处理技术，对其截留特性进行了研究。在实际装置中测量了盐截留率、有机物截留率和微污染物截留率。采用浸没式平板纳滤膜组件研究了负压式纳滤膜过滤系统。采用溶液扩散模型和扩展的能斯特-普朗克方程对盐排斥现象进行了分析。硫酸盐截留率低于扩展能斯特-普朗克方程的预测值。在浸没式纳滤的小通量操作条件下，膜分离过程中的浓差极化可以忽略。在含砷地下水处理中，在扩展的能斯特-普朗克方程中确定了一个亲和项。针对孟加拉国含砷地下水的处理，开发了自行车式手动泵连接纳滤装置。

Rejection characteristics of nanofiltration and reverse osmosis membranes were investigated in the applications of drinking water treatment of surface and/or underground water and in the applications of leachate treatment. Molecular weight cutoff sizes of commercially available membranes were determined by alcohols and by sugars. Some membranes with relatively low nominal desalination ratio showed more than 90% rejection of natural organic matters in the measurement of TOC.There was less correlation between rejection of organic matters and rejection of salts. This type of insignificant correlation was found in the case not only of surface water treatment but of underground water treatment and of leachate treatment. Bis phenol A, which is thought to be one of the endocrine disrupting chemicals showed lower rejection than the predicted value from the molecular weight rejection relationship obtained from sugar rejection. One of the actual leachate treatment facilities using high rejection reverse osmosis treatment was focused for the rejection characteristics survey. Salt rejections, organic matters rejection and micropollutants rejections were measured in that actual plant. A suction nanofiltration system was investigated using an immersed flat sheet nanofiltration module. Salt rejections were analyzed by using the well known solution diffusion model and the Extended Nernst Planck equations. Sulfate rejection was lower than the predicted value of the Extended Nernst Planck equation. The concentration polarization in membrane separation was calculated to be negligible in the case of small flux operation of immersed nanofiltration. In the arsenic contained ground water treatment, an affinity term was identified in the Extended Nernst Planck equation. A nanofiltration device connected with bicycle type manual pump was developed for the treatment of arsenic contained ground water treatment in Bangladesh.