Performance intensification of BzP photo-catalytic degradation through adding exogenous oxidant

This study was conducted to investigate the photocatalytic removal of Benzylparaben (BzP) using UVC/ZnO (UZ) process in the presence of H2O2 (UZH) from aqueous solutions. The results indicated that mean size and surface area of nano-ZnO were 30 nm and 150 m(2)/g, respectively. The maximum degradation and mineralization of BzP (15 mg L-1) by UZ process under optimum operational conditions (pH: 9.0, catalyst dose: 1 gL(-1) within 90 min reaction), were over 67.37% and 42% of TOC, respectively. The addition of H2O2 (up to 10 mmol L-1) along with UV/ZnO resulted to 100% and 55% removal of BzP and TOC during 25 min of reaction time, respectively. The kinetic studies indicated r(obs) value for UZH process was about 1101.6, 413.12, 367.22, 27.31 and 18.99 times than that of the ZnO, H2O2, UV, UZ and UV/H2O2 (UH), respectively. The values of energy consumption for UV, UZ, UH and UZH were calculated 1280, 95.2, 66.2 and 3.48 kWh m(-3), respectively. BzP was converted to a biodegradable waste after a 90 min and 25 min irradiation time in the UV/ZnO and UV/ZnO/H2O2 processes, respectively.