| dc.description.abstract | 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. | en_US |