Non-radical reaction systems for environmental remediation attracted increasing attention due to the merits including adaption to wide pH circumstances, resistance to inorganic (e.g. chlorine, phosphate, carbonate) or organic (e.g. humic acid) background constituents, mild redox potential and high selectivity. The heterogeneous and homogeneous non-radical reaction system was investigated by using nitrogen-doped carbonaceous nanospheres and Fe-TAML (tetra-amido macrocyclic ligand) as catalysts for activation of peroxymonosulfate (PMS) and H2O2, respectively. The carbocatalyst was obtained by carbonization of polypyrrole that was synthesized through a scalable chemical oxidative polymerization. The carbocatalyst based system displayed selectivity in the degradation of various aromatic compounds with different substituents, which depended on the metastable oxidation state of the catalyst formed by electron transfer from the catalysts to PMS, and the ionization potential (IP) of the organics. The homogeneous system of Fe-TAML/H2O2 showed different activity in organic degradation at pH 7 and 10. A quantitative structural-activity relationship (QSAR) model was built to understand the enzyme-like non-radical reaction. Results indicated that in both non-radical reactions, acidic compounds are recalcitrant for degradation. Therefore, the techniques based on non-radical reactions probably are inefficient in removal of such acidic micropollutants like ibuprofen, metronidazole. It could be an easy way to differentiate the radical or non-radical pathways by testing the competitive degradation of phenol and benzoic acid.

Selectively degradation of organic pollutants in the homogeneous or heterogeneous non-radical reactions

255th National Meeting (2018)

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