Activation of peroxydisulfate by MIL-101(Fe)/g-C3N4 for 2-chlorophenol–contaminated soil: parameter optimization by response surface methodology.

Purpose: Soil organic matter pollution is a serious threat to the human living environment. The purpose of this paper is to investigate the effect of MIL-101(Fe)/g-C₃N₄ catalyzed peroxynitrite degradation of 2-chlorophenol in soil and to analyze the reaction mechanism and further to explore the optimal parameters of this reaction system with utilizing the mathematical model. Methods: MIL-101(Fe)/g-C₃N₄ was successfully obtained by hydrothermal synthesis method by growing MIL-101(Fe) on the surface of g-C₃N₄ to catalyze the degradation of 2-CP (2-chlorophenol) in soil by sodium persulfate. The influence factors on the removal rate of 2-CP were analyzed by the response surface methodology (RSM) and combined with theoretical calculations. RSM can be used to model continuous variable surfaces with less data and determine the optimal level range. Results: MIL-101(Fe)/g-C₃N₄ had a good catalytic performance due to its good catalytic properties and the adsorption of g-C₃N₄ on 2-CP in the system and made the best removal rate of 2-CP increase to 91.2%. The correlation of model fitting results was significant, and the verification of its optimal parameters yielded results with an error of only 4.1%. Conclusion: Further studies revealed that SO₄^•− and ^•OH were the reactive radicals, and SO₄^•− was the dominant, which impelled Fe²⁺ and Fe³⁺ to interconvert in the complex system. Possible degradation pathways were derived by analyzing the intermediates. Generally, this experiment provides some ideas for future research of MOFs in soil organic pollutant removal systems. [ABSTRACT FROM AUTHOR]