Electrochemical reductive extraction of tin from semiconductor plating process wastewater was experimented using synthetic wastewater. Copper and graphite plate were used as a cathode and an anode, respectively. The tin extraction could be optimized in pH 0.5 and polar space of 60 mm. The extraction rate of tin per minute was increased as current and initial tin concentration increased, and more than 87% and 97% of tin could be extracted within 80 minutes at 500 mg/L and 1,000 mg/L of initial tin concentration, respectively. The electrochemical reaction orders and kinetic coefficients were 1.24 ~ 1.26 and 0.004 ~ 0.006 (L/mg)(n − 1)min−1. The residual concentration of tin could be expressed as Ct= (Co −0.246+ 0.0012t)−4.065.

Economic and environmental aspects of electrochemical copper recovery from LCD manufacturing process and through hole plating process for PCB circuit board wastewater were evaluated. The extraction rate of copper per unit energy was decreased as HRT increased and initial copper concentration decreased. About 65 minutes was determined as the optimal HRTs which could maximize the productivity of copper recovery on energy. The extracted mass of copper from the wastewater were 0.045 g at 50 mg Cu/L, 0.083 g at 1,000 mg Cu/L and 0.098 g at 3,000 mg Cu/L by unit energy (Wh) for 60 minutes, respectively. LCA (Life Cycle Assessment) technique determined the electrochemical recovery of copper to have more effect on global warming than other environmental impact categories.

Electrochemical reductive extraction of copper from LCD manufacturing process and through hole plating process for PCB circuit board wastewater was experimented using synthetic wastewater. Copper plate which could be used as raw material through melting with extracted copper from wastewater and graphite plate were used as a cathode and an anode, respectively. The copper extraction could be optimized in pH 2 and polar space of 45mm. The extraction rate of copper per unit energy was decreased as HRT increased and initial copper concentration decreased. As the optimal HRTs which could maximize the productivity for copper on energy, 80 ~ 110 min at 50 mg/L, 64 min at 1,000 mg/L and 77 ~ 98 min at 3,000 mg/L were determined, respectively.