本研究探討聚嗍碸與磺酸化聚嗍碸為基材進行高分子光接枝聚合親水性單體 (丙烯酸)製備親水性薄膜應用於奈米過濾去除含金屬離子之廢水。本研究利用非對稱型離子交換高分子(磺酸化聚嗍碸)、光接枝聚丙烯酸接枝膜、離子化聚丙烯酸接枝膜進行奈米過濾去除含金屬離子之廢水之探討，本研究顯示當鑄膜溶液中的聚嗍碸高分子由18.9wt%增加到22.6wt%，奈米過濾金屬離子溶液的選擇性增加，而透過率減少，高分子濃度21.4wt%以下時表層缺陷導致所製備的薄膜拒鹽率介於10%-15%之間，透水量則有65-20 kg/m2hr，另外本研究顯示當以磺酸化聚嗍碸高分子為鑄膜溶液，奈米過濾金屬離子溶液的選擇性增加至20%，而透過率減少至30 kg/m2hr，高分子濃度22.6wt%時表層太厚無法以20kg/cm2之壓力進行奈米過濾，以磺酸化聚嗍碸高分子薄膜則有優於聚嗍碸薄膜的過濾效果與流量，其原因為當磺酸接枝程度越高時提高其親水性，增進薄膜膨潤度，可有效提升透過量及選擇比。
本研究亦探討進行光聚合反應對光聚合超薄膜之製備與特性、型態及其對奈米過濾分離性能之影響，研究結果發現以高分子濃度21.4wt%聚嗍碸薄膜為基礎所製備之接枝薄膜表面會隨丙烯酸單體濃度愈高，薄膜拒鹽率提昇且透水率下降，但拒鹽率介於12%-21%之間，出水量則有30-10 kg/m2hr，另一方面以丙烯酸 (AA) 利用UV光誘導接枝薄膜 (PSF-AA)進行離子交換：丙烯酸濃度為15%時，以Al3+離子交換薄膜擁有較良好奈米過濾性能，拒鹽率介於42%之間，出水量則有10 kg/m2hr，比較薄膜離子交換種類時其拒鹽率Na+<、Mg2+<、Al3+，而透水量則呈現相反之趨勢，研究中以Al3+離子交換薄膜進行之過濾離子大小對分離性能之影響，研究結果顯示出隨銨離子之分子量增加去除率也隨之升高，拒鹽率可提升至約為80%；而操作壓力變化對流量也有具有影響，流量隨著壓力的提高對金屬離子溶液也有增加的趨勢，在5kg/cm2時流量為1.74 kg/m2 hr，壓力提高至20kg/cm2時其流量則增加為4.91 kg/m2 hr。 The purposes of this investigation focus on the preparation of nanofiltration membranes (NF) and their characteristics for wastewater treatment. The nanofiltration membranes were used by considering the asymmetric polysulfone membranes, ion exchanged polysulfone membranes, and photografted poly acrylic acid membranes. it was found that the low rejection rate of asymmetric polysulfone membranes were found in NF process. The permeation rate and salt rejection of asymmetric membrane were 65-20 Kg/m2hr and 10%-15%, respectively. On the other hand, the improvement of separation performance of NF membranes was achieved by applying the sulfonated polysulfone as the membrane material. It was successful prepared by asymmetric sulfonated membrane and enhanced both of permeation rate and salt rejection rate in NF process. It was found that the improvement in NF separation performance was due to the increase in swelling properties and improvement in hydrophilicity of membranes.
The photografting method was used to enhance the NF separation performance of polysulfone membranes. The preparation conditions, characteristics and morphology of photografted membranes were investigated in this study. It was found that the photografted poly acrylic acid enhanced the salt rejection rate and decreased the permeation rate of modified membranes. The permeation rate and salt rejection of photografted membrane were 30-10 Kg/m2hr and 12%-21%, respectively. Those photografted membranes were upgraded the separation performance by ion exchanged method. It was found that the exchanged ions strongly influenced the permeation rate and salt rejection due to the hydrophilic properties. The salt rejection rate of those ion exchanged membranes increased with the exchanged ion in the serial, Na+ < Mg+2< Al+3. The inverse trend was found in the permeation behavior of ion exchanged photografted membranes. In this investigation, the influence of molecular size of ion on the permeation behavior was investigated by using the Al+3 exchanged membranes. The results indicated that over 80% rejection can be achieved by using the secondary ammonia and tertiary ammonia as the permeates in NF process. The NF permeation tests also showed that the operating pressure and temperature showed the significantly affect on the permeation rate and salt rejection.
