Research Progress of Iron-Based Catalysts in Ozonation Wastewater Treatment

On account of the rich contents of iron-based catalysts, low preparation costs, and good effects, they play important roles in various fields of water treatment. There are many kinds of iron oxides, which have been employed in catalytic ozone oxidation processes. However, a thorough analysis of their syntheses, characterization techniques, reactions affecting variables, and mechanistic applications is lacking in the catalytic ozone oxidation sector. It is necessary to search for the catalytic efficiencies of different types of iron-based catalysts in the ozone system and elucidate the activation mechanisms of hydroxyl radicals by iron-based catalysts. In this paper, the synthesis methods, characterization techniques, and practical application fields are summarized in detail. The catalytic performances of iron-based catalysts in the ozone system are explored. The effects of solution pH, reaction temperature, catalyst addition amount, ozone concentration, and inorganic anions on the degradations of organic pollutants and the stability of an iron-based catalyst/oxidant system are also discussed. The activation mechanisms of free radicals and the removal mechanisms of organic pollutants in the iron-based catalyst/ozone system are revealed by a detection method, characterization technology, and theoretical analysis. The potential preparation methods, practical applications, auxiliary technologies, and influences on ozone catalysis are prospected.