Effect of Solution Matrix on TiO ₂ Photocatalytic Degradation of 2-Chlorobiphenyl

Abstract

The effects of solution matrices, i.e., pH, inorganic ions, and humic acids, on the TiO2 photocatalytic degradation of 2-chlorobiphenyl (2-CB) were investigated. A lower solution pH was found to be favorable for the degradation in the pH range of 3 to 11. Chloride ions showed no rate effect at pH 10. The inhibition by chloride ions at pH 4 was more than that at pH 7. Carbonate/bicarbonate showed an inhibition effect on the degradation at pH 10 and pH 11. Magnesium ions inhibited the degradation under alkaline conditions, but showed no rate effect at pH 4. Humic acids were found to inhibit 2-CB degradation. The degradation rate decreased with increasing concentration of humic acid and leveled off at the concentration of 5 μg/mL. Key words: Photocatalytic degradation; titanium dioxide (TiO2); 2-chlorobiphenyl (2-CB)