Intensification strategies for thermal H2O2-based advanced oxidation processes: Current trends and future perspectives

H2O2-based advanced oxidation technologies, commonly Fenton process or Catalytic Wet Peroxide Oxidation (CWPO), have been widely studied and applied over the past decades for wastewater treatment due to their ability generate highly oxidizing species, HO• HOO• radicals, along with a low selectivity which allow degradation of wide range pollutants . Nonetheless, these technologies present some limitations. In case Fenton, requirement acidic media (pH: 3), loss catalyst at end reaction because it is dissolved, inactivation caused by certain intermediates (i.e. oxalic acid) that forms complexes compromising its efficiency. For CWPO, main drawbacks in this heterogeneous are mainly associated relative activity stability catalysts employed. All shortcomings can be solved through intensification, generally involves CWPO increasing temperature application an external radiation, being most interesting ones UV–vis radiation (photo-assisted technologies), microwave inherently presents advantages working high temperature. This paper gathers recent advances explored thermal-intensified H2O2–based summarizing results obtained each intensification strategy outlining where future efforts should focused.