Removal of pollutants from gas streams using Fenton (-like)-based oxidation systems: A review

Emissions of pollutants such as SO2, NOx, CO, Hg, H2S, VOCs, etc. from various gas streams (e.g., flue gas, waste gas, fuel gas, industrial gas, biogas, etc.) not only pollute the environment, but also endanger human health. Various technologies are developed to remove these pollutants. Among them, Fenton (-like)-based oxidation systems have received wide attention due to its strong oxidation ability, low technical and installation requirements, promising simultaneous removal capability of multi-pollutants and environmentally friendly process. However, so far, the special review focusing on removal technologies of pollutants from gas streams using Fenton (-like)-based oxidation systems is not reported. This review summarizes the latest advances in removal of these pollutants from gas streams using Fenton (-like)-based oxidation systems. The activation principle, removal performance, mechanism, merits and shortcomings of these pollutants removal technologies are reviewed. The existing challenges, suggestions and prospect are commented. Results show that most of Fenton (-like)-based oxidation systems can achieve high pollutant removal efficiency and realize simultaneous removal of multipollutants. However, a series of existing problems (e.g. metal ion recovery, side reactions, low radical utilization, heterogeneous mass transfer limitation, sustainability and stability of system operation, metal ions leakage and deactivation of metallic oxides, high cost, etc.) pose various challenges for the development of these technologies. The synthesis of efficient and stable catalysts, enhancement of multiphase mass transfer, optimization design of reactor, development of additives and synergism use of multi-technologies are the promising strategies to overcome these defects.