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年度	105	專案性質	實驗性質
專案類別	研究專案	研究主題	整治
申請機構	國立台灣大學	申請系所	環境工程學研究所
專案主持人	侯嘉洪	職等/職稱	助理教授
專案中文名稱	建構電容去離子系統整合模組處理含砷地下水之先驅試驗
中文關鍵字	電容去離子技術、砷、地下水整治
專案英文名稱	System integration of capactive deionization technology for the remediation of arsenic contamined groundwater
英文關鍵字	Capacitive Deionization, Arsenic, Groundwater Remediation
執行金額	999,900元
執行期間	2015/11/17 至 2016/11/16
計畫中文摘要	本研究計畫之目的在於考量電容去離子技術(capacitive deionization, CDI)於地下水整治之實場應用時可能遭遇之干擾與困難，建構電容去離子技術系統整合模組，進行CDI 技術處理含砷地下水之先驅試驗。工作內容包含(1)含砷地下水之水質分析，(2)結合CDI 技術與微過濾薄膜技術(microfiltration, MF)，建構電容去離子技術系統整合模組(MF-CDI)，(3)以MF-CDI 系統模組進行實驗室規模模場試驗，評估移除水體砷污染之成效，並探討地下水中之溶解性離子對於CDI 技術以電吸附機制移除水體中砷污染時，可能造成之干擾行為。同時，以表面修飾技術增加活性碳電極對砷的吸附容量。 水質分析結果指出，地下水中富含多種陰陽離子，而總砷濃度為0.13mg/L。模組試驗結果則顯示，CDI 模組僅需施加一低電壓(1.2 V)，最佳之砷去除率可達76%，使出流水砷濃度符合飲用水水源標準及農業灌溉用水水源標準(0.05 mg/L)。同時，CDI 模組可同時去除水體中其它帶電荷離子，總溶解固體濃度(total dissolved solids,TDS)之最佳去除率可達67%。另外，由於地下水體中陰離子的存在(如硝酸根離子)，會與砷產生競爭性的電吸附行為，故需進一步加強CDI 模組對於砷的去除能力。本研究將陰離子交換樹脂塗均勻的批覆於活性碳電極表面，除可提升CDI 模組對砷的電吸附容量外，亦可有效改善活性碳電極的親水性，並增加其電化學穩定性。綜合評估本研究所架設之MF-CDI 系統模組，於實務應用上適合以抽取處理法(pump and treat, P&T)將地下水抽至地表，MF-CDI 系統模組則作為地表處理設備，進行地下水砷污染之移除作業。依據實驗結果，CDI 單元處理含砷地下水之能耗為0.495 kWh/m3，電力消耗低為其主要優勢，與現有之水處理技術相比，具有操作成本的優勢，具進一步發展實地模場試驗之潛力。
計畫英文摘要	The objective of this study is to develop an integrated module system by coupling microfiltration (MF) and CDI technology for remediation of arsenic contaminated groundwater. In addition, the effects of non–dissolved matter (suspended solids, microbial, organic matters, etc.) and dissolved substances (such as alkali metal ions, alkaline–earth metal ions, salt, heavy metals, manganese ions and iron ions) in natural groundwater on the CDI performance have been studied in this study. Furthermore, surface modification of porous carbon electrode could be conducted to improve the electrosorpion performance and selective removal of arsenic over others substrates (i.e., sodium chloride and heavy metal ions). An integrated module system of MFCDI has been developed in the present work. MF unit is a pretreatment process for removing non–dissolved matters from the practical groundwater. As evidenced by the single-pass CDI experiments, an efficiency of 76% for asenic removal can be achieved at an applied voltage of 1.2 V. Notabley, negatively charged species (e.g., Cl−, NO3 −, SO4 2−) could compete with arsenic to be eleroadsorbed onto the anode in the CDI cell. In order to improve arsenic removal from aqueous solutions, the activated carbon electrodes were coated with anion-exchange resin layer. The surface-modified activated carbon electrode has improved hydrophilic properties, good capacitive behaviors, and larger salt adsorption capacity. As evidenced, the electrosorption capacity of surface modified activated carbon electrodes is calculated to be 0.0057 mg/g. Consequently, we have demonstrated that integrated MF-CDI system has high potential for applications for arseniccontaminated groundwater and removal capacity of activated carbon electrodes can be significantly enhanced by coating an anion-exchange resin layer on the electrode surface.