Photocatalytic treatment of wastewater contaminated with organic waste and copper ions from the semiconductor industry

Simultaneous decontamination of organic compounds and copper ions in the wastewater discharged from semiconductor manufacturing facilities by a UV/TiO2 photocatalytic degradation was investigated in this study. Two organic compounds of ethyl lactate and phenol and copper ions were studied due to their common applications in various wafer fabrication processes and higher toxicities. The optimal TiO2 dosage and initial pH for the photocatalytic oxidation of ethyl lactate and phenol were 0.1 g/L and 3.0-4.0. Photocatalytic degradation under these optimal conditions was able to simultaneously mineralize those solvents and remove copper(II) in the synthetic wastewater. Under anoxic condition, oxygen inhibited copper reduction and copper(11) ions were removed through precipitation. Under anaerobic conditions, the removal rate of copper(II) ions and the rate of reduction of the organic solvents content were lower than that in the aerobic condition.