Surface Modification of NF/RO Membranes Using Concentration-Polarization-Enhanced Radical Graft Polymerization to Improve PPCPs Removal and Fouling Resistance

[[abstract]]新興污染物(ECs)包含藥物和個人保健用品(PPCPs)、內分泌干擾物質、殺蟲劑、消毒副產物、揮 發性有機物、及重金屬等，近年經由廢水大量排放至自然界中，其多具有生物累積性，會對水中魚類 及覓食鳥類造成毒性衝擊，或內分泌系統改變，但傳統淨水與污水處理程序卻無法將之有效去除，故 發展有效且經濟的的處理技術非常重要，其中又以奈米(NF)/逆滲透(RO)薄膜過濾成效較好且沒有副產 物產生。 然近年對 NF/RO去除 ECs/PPCPs的研究成果分歧，並發現 NF/RO對某些新興污染物會有先吸附 而後貫穿的情形，故 NF/RO 對微量新興污染物之去除機制與效能評估需要深入探討；而薄膜在操作 上常遇到濃度極化導致膜面積垢、產水量降低、需增增加化學清洗導致濾程縮短以及成本增加，同時 薄膜效能隨著積垢情況的嚴重與化學清洗次數的增加而逐漸衰減，導致小分子容易貫穿薄膜而降低去 除效果等問題，故如何提昇薄膜的抗垢性及對目標污染物的去除率，為擴大薄膜應用所必須解決的關 鍵課題。 有鑑於此，本研究將開發創新之「以濃度及化強化自由基嫁接聚合」現地改質膜面的方法，利用 薄膜操作中無可避免的「濃度極化」現象，讓聚合單體與誘發劑在膜面快速累積高濃度而達到「強化 高分子自由基嫁接聚合」，不但可大幅節省聚合單體的使用濃度（節省成本）、提高反應效率、縮短反 應時間，更有可現地直接操作改質等優點。研究將針對選用之 NF/RO 薄膜，以不同的聚合單體與誘 發劑之組合以系統性的方式進行改質，搭配改質前後膜面分析鑑定結果、改質薄膜對 PPCPs之去除效 率與抗垢性測試等，並將研究成果與本團對前期使用無改質薄膜之操作效果進行比較，以評估最佳之 薄膜改質參數，同時確立改質後薄膜對 PPCPs之主要去除機制與積垢特性，搭配積垢預測模式之建立 與改質膜面對化學清洗之耐受性測試。研究成果將可直接供實廠應用與操作依循。[[abstract]]Large amounts of emerging contaminants (ECs) such as pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs) which will cause detrimental health effects are discharged into the environment through the effluents of wastewater treatment plants everyday However, traditional drinking water and wastewater treatment plants usually don’t have the ability to remove them. Therefore, it is crucial to establish suitable treatment processes for their removal, and nanofiltration (NF) and reverse osmosis (RO) are proven as effective techniques. Although there are successful cases of ECs removal by NF/RO, some previous studies showed disparate results and the mechanisms of PPCPs adsorption on membrane surface are not well established. Moreover, membrane fouling arose from concentration polarization is the major problem which shortens membrane operation period and degrades membrane performance. Researches regarding anti-fouling effect on membrane surface as well as increasing ECs removal deserve more attention. The objectives of this research are to establish an efficient in situ concentration-polarization-enhanced graft-polymerization method for membrane modification to reduce the amount of reagents as well as increase reaction efficiency, to improve the anti-fouling effect as well as PPCPs removal, to examine the physico-chemical properties of modified membrane surface and fouling layer to have a deeper insight of the surface characteristics, and to compare the performance of that using unmodified membranes to evaluate the effectiveness of surface modification. Duration test of modified membranes using chemical cleaning agents will be tested and the mechanisms of PPCPs rejection by NF/RO and the fouling mechanisms and predicting models will be proposed as well. The established method with optimized operating parameters can be applied in any field NF/RO plants directly.[[note]]MOST103-2221-E327-00