UV/H2O2: An efficient aqueous advanced oxidation process for VOCs removal

Catalyst deactivation and secondary pollution are the critical issues challenging the traditional heterogeneous catalysis (gas-solid) methods for VOCs removal at room temperature. This process strongly depends on the available (OH)-O-center dot radicals. Because of the facile formation of (OH)-O-center dot radicals, H2O2-based advanced oxidation processes (AOPs) may facilitate VOCs removal. In this paper, UV/H2O2, for the first time, was employed to degrade continuous-flow gaseous toluene in batch system with comparison to UV/Fenton and Fenton process. UV/H2O2 process was identified to moderately generate (OH)-O-center dot radicals and yielded removal efficiency higher than 80% without any loss while it gradually declined to 32% and 45% within 120 min in the Fenton and UV/Fenton process, respectively. No emission of gaseous intermediates was identified at the outlet in all the AOPs. Most of the removed toluene was oxidized into CO2 in the UV/H2O2 process, however, many organic intermediates were generated in the solution of Fenton and UV/Fenton process. The superior performance of UV/H2O2 process was mainly ascribed to the continuous formation of (OH)-O-center dot. This study demonstrates that UV/H2O2 process can be applied as an efficient and environment-benign technology for VOCs treatment. (C) 2017 Elsevier B.V. All rights reserved.