4-chlorophenol (4-CP) could be rapidly mineralized by using Fenton reaction. However, massive iron sludge will be generated because of the excessive consumption of iron salt and poor recycling of FeIII back to FeII. In this paper, by introducing hydrogen gas and solid catalyst Pd/NH2-MIL-101(Cr) to classic Fenton reactor, the novel system named MHACF-NH2-MIL-101(Cr) was constructed. Much less FeII was needed in this system because the hydrogen could significantly accelerate the regeneration of FeII. The catalyst improved the utilization of H2. The degradation reaction of 4-CP could be driven by using only trace amount of FeII. It could be rapidly degraded by the hydroxyl radical detected by the 4-Hydroxy-benzoicacid which is the oxidative product of benzoic acid and hydroxyl radical. The effects of dosage of ferrous salt, H2O2 and catalyst, H2 flow, Pd content, and initial pH of and concentration of 4-CP aqueous solution were investigated. The robustness and morphology changes of this catalytic material were also systematically analysed. By clarifying the role of this solid MOFs material in this hydrogen-mediated Fenton reaction system, it will provide a new direction for the research and development of advanced oxidation processes with high efficiency and low sludge generation in future.
Keywords: FeII regeneration; NH2-MIL-101(Cr); Pd0; enhanced Fenton reaction; hydrogen.