Heterogeneous photodegradation of mesotrione in nano α-Fe2O3/oxalate system under UV light irradiation

RSC Advances Pub Date: 2015-01-07 DOI: 10.1039/C4RA11871E

Abstract

The aim of this study is to investigate the behavior of mesotrione herbicide photodegradation under UV light irradiation with co-existence of iron oxides and oxalic acid. α-Fe2O3 and oxalate can set up a novel photo-Fenton-like system under UV irradiation in nature environment without H2O2 additional. The adsorption capacity of mesotrione was investigated in the dark by batch experiment, and the results were well fitted by Langmuir model. The effects of the iron oxide dosage, initial concentration of oxalic acid (C0ox), mesotrione, and initial pH on the mesotrione photodegradation were investigated. The photoproduction of hydroxyl radicals (˙OH) during the photochemical process was also examined in diverse catalytic systems. The results indicated that mesotrione photodegradation follows pseudo-first-order kinetics. The mesotrione photodegradation moves slowly in the presence of α-Fe2O3 or oxalic acid. Interestingly, we found out that mesotrione photodegradation was distinctly enhanced when α-Fe2O3 and oxalic acid co-existed under UV irradiation. We learned that the combination of α-Fe2O3 and an oxalate system is an excellent agent to accelerate mesotrione herbicide decomposition. Results from this study could be further applied in the natural environment to facilitate environmental protection.

Graphical abstract: Heterogeneous photodegradation of mesotrione in nano α-Fe2O3/oxalate system under UV light irradiation
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