Enhancing ethylbenzene vapors degradation in a hybrid system based on photocatalytic oxidation UV/TiO2-In and a biofiltration process.

The use of hybrid processes for the continuous degradation of ethylbenzene (EB) vapors has been evaluated. The hybrid system consists of an UV/TiO(2)-In photooxidation coupled with a biofiltration process. Both the photocatalytic system using P25-Degussa or indium-doped TiO(2) catalysts and the photolytic process were performed at UV-wavelengths of 254 nm and 365 nm. The experiments were carried out in an annular plug flow photoreactor packed with granular perlite previously impregnated with the catalysts, and in a glass biofilter packed with perlite and inoculated with a microbial consortium. Both reactors were operated at an inlet loading rate of 127 g m(-3)h(-1). The greatest degradation rate of EB (0.414 ng m(-2)min(-1)) was obtained with the TiO(2)-In 1%/365 nm photocatalytic system. The elimination capacity (EC) obtained in the control biofilter had values ≈ 60 g m(-3)h(-1). Consequently, the coupled system was operated for 15 days, and a maximal EC of 275 g m(-3)h(-1). Thus, the results indicate that the use of hybrid processes enhanced the EB vapor degradation and that this could be a promising technology for the abatement of recalcitrant volatile organic compounds.