| 摘要: | 本研究利用渦流電解系統探討PCB含銅廢水之處理效能，廢水源自國內某印刷電路板銅線代工廠，該廠廢水主要為微蝕銅廢液、化學銅廢液及硝酸銅廢液，其皆屬高濃度含銅廢水，三道廢水具有不同特性，如化學銅廢液呈現強鹼，而微蝕銅廢液及硝酸銅廢液則屬強酸，另外，化學銅廢液亦含有高化學需氧量(COD)。於實驗結果方面，操作於電解系統不同電流條件(8 A-16 A)，其對化學銅廢液之銅去效率可達94.7% - 99.2%，而對微蝕銅廢液及硝酸銅廢液之銅去除效率則分別為16.0% - 42.9%及14.3% - 39.0%，顯示渦流電解系統對化學銅廢液有最佳去除效率；反之，對微蝕銅廢液及硝酸銅廢液效果則不佳，推測原因為蝕銅廢液及硝酸銅廢液屬強酸溶液，在銅回收之過程可能導致銅再次溶出，使去除效率下降。如進一步探討渦流系統於在不同pH值對三道廢水銅之去除效能，結果顯示較高pH值條件下確實有利於廢水銅之去除。在不同混合比例條件下，實驗結果指出化學銅比例較高者有較佳去除效率，且去除效率隨操作溫度增加而提升，因溫度越高有較高反應速率；另外，在長效性能之測試，本研究利用渦流電解系統可連續穩定操作72小時以上。透過XRF及ICP儀器分析，結果顯示不同渦流電解系統操作條件(不同操作電流、pH值及廢液混合比例)下，回收銅的純度大多可高於98%，指出渦流電解系統可獲得高純度電解銅。整體而言，本研究所利用渦流電解系統在適當條件下，可有效去除廢水中之銅，且回收電解銅之純度亦相當高，證實渦流電解系統有潛力應用於實廠。;This study aims to use electrolytic system for the removal of wastewater containing copper for printed circuit board (PCB) industry. The wastewater used in this study came from copper wire foundry of PCB in Taiwan. Wastewater mainly includes solution of micro-etching copper, solution of chemical copper and solution of nitrate copper, respectively. For characteristics of three wastewaters, chemical copper presented strong alkaline, while micro-etching copper and nitrate copper were strong acid. In addition, analytical results indicated that wastewater of chemical copper had the highest chemical oxygen demand (COD). With various applied current (8 A - 16 A), Cu2+ removal efficiency of three wastewater achieved with electrolysis were 94.7% - 99.2% (chemical copper), 16.0% - 42.9% (micro-etching copper) and 14.3% - 39.0% (nitrate copper), respectively, indicating that electrolysis had the highest performance as applied for the treatment of chemical copper wastewater. Conversely, electrolysis performance was unsatisfactory for the treatment of micro-etching copper and nitrate copper. It may be ascribed to low pH value (micro-etching copper and nitrate copper were strong acid solution) to cause copper recovered in electrode was dissolved, resulting in lower Cu2+ removal efficiency. For effect of pH on electrolytic system, results indicated that electrolysis performance increased with increasing pH value. Also, effect of ratio of different wastewater on electrolytic system was explored, indicating that it was beneficial to Cu2+ removal efficiency with increasing ratio of chemical copper. In addition, results indicated that a higher Cu2+ removal efficiency could be obtained as electrolytic system was operated at a higher temperature due to high reaction rate. For durability test, electrolysis could be maintained at ≥ 72 hr stably. On the other hand, results of XRF and ICP, purity of copper recovered by electrolysis could almost achieve at ≥ 98%, indicating that high purity copper can be obtained as electrolysis was applied for the treatment of wastewater. Overall, high Cu2+ removal efficiency could be reached if electrolysis was operated at appropriate conditions, demonstrating that electrolysis has potential to be applied for the treatment of real field wastewater. |
