TiO2 photocatalytic degradation of UV filter para-aminobenzoic acid under artificial and solar illumination

BACKGROUND: The presence of pharmaceutical and personal care products' (PPCPs) residues in the aquatic environment is an emerging issue due to their uncontrolled release, through grey water, and accumulation in the environment that may affect living organisms, ecosystems and public health. As a result, efforts are being made to develop methods to inactivate or eliminate this class of substance in the environment. RESULTS: The heterogeneous photocatalytic degradation of para-aminobenzoic acid (PABA), one of the components that are present in many types of PPCPs, has been investigated in aqueous solutions using artificial and solar illumination. The effects of TiO2 P25 and TiO2 Kronos vlp 7000 and their concentration (0.25-1.5 g L-1), initial concentration of H2O2 (0.25-0.2 g L-1), pH of the solution (3-10), temperature (280-323 K), as well as the type of radiation (artificial, solar) on initial reaction rates were evaluated in a bench-scale Pyrex reactor. Solar-induced photocatalytic degradation of PABA was accompanied by the formation of several hydroxylated aromatic intermediates, while a decrease in the parent compound toxicity has been observed after treatment in the presence of TiO2 P25. CONCLUSION: According to the results presented in this study, the TiO2 photocatalytic process in the presence of artificial and solar illumination is an efficient methodology for PABA degradation and its toxicity reduction. (C) 2015 Society of Chemical Industry