以倒極∕電透析法去除水中氯化銨鹽之可行性研究

The Feasibility Study of Ammonium Chloride Removal in Aqueous Solution Using Electro-Dialysis Process

本研究針對現行產業於實廠建置氨氮處理設備時，為解決場地空間不足及降低處理時程等問題，採用電透析法及倒極電透析法針對廢水中產生的氨氮進行處理之可行性評估。研究結果顯示：pH值為7以上時，有較佳的去除表現，當pH值低於7以下去除效率較無明顯之效果。電透析法可在30分鐘後即可對水中氨氮達到去除的效果，當流速越快去除效果越差，反之流速越慢去除效果越好，故流速與去除率成反比。此外，在不同pH值之試驗中可驗證：pH值增加去除效率亦隨之升高，反之當pH值下降去除效率亦隨之下降；且水中氨氮去除率增加，產水之導電度亦隨之下降。再者，在不同起始氨氮濃度中，以電透析法法去除水中氨氮之最佳去除效率為71%（NH_4+離子濃度為1,600 mg/L、pH=8及流速=3 L/min），相同條件下亦可得以倒極電透析法去除水中氨氮之最佳去除效率為72%，故以倒極電透析法去除水中氨氮只比單以電透析法增加些微之去除效益，整體經濟效益不大。

In recent years, the ammonium in waste effluent concentration has attracted global attention. In present, various techniques have commonly used to remove ammonium or nitrogen from wastewater. In this study, the small scale electric dialysis （ED） equipment has established in the application of ammonium removal by using self-prepared ammonium solution. Some control facts that affect the removal efficiency were carefully examined in this laboratory simulation, including and pH, concentration and flow rate. Experimental results indicated that adjusting pH could affect significantly the removal efficiency of ammonium chloride. The pH values equal to 7 or higher illustrated better removal performance. While the pH is below than 7, the following removal efficiency decreased clearly. Moreover, in 30 minutes, the electric dialysis could reach the obvious removal of ammonium. The removal effect was decreased while the flow rate increased, whereas the slower flow rate illustrated better removal efficiency. The best result was achieved at low rate at 3L/min. Therefore, at various initial ammonium concentrations, the best removal efficiency of 1600 ppm solution was 72%, while the best removal efficiency of 800 ppm solution was 70. In the experiment of electric dialysis reversal （EDR）, the treatment efficiency decreased at first 30 minutes, and slowly came back after 50 minutes. The conductivity followed the direct proportional to the removal efficiency. The best condition was achieved up to 72% removal efficiency at EDR experiment under the flow rate=3 L/min, and pH=8.