[Fe(Ox)3]3- complex as a photodegradation agent at neutral pH: Advances and limitations. (March 2018)

• Record Type: Journal Article
• Authors: Pozdnyakov, Ivan; Sherin, Peter; Bazhin, Nikolai; Plyusnin, Victor
• Is Part Of: Chemosphere. Volume 195(2018)
• Page Start: 839
• Page End: 846
• Publication Date: 2018-03
• Subjects: Ferrioxalate -- 2, 4-DB -- Hydroxyl radical -- Photodegradation -- Stationary photolysis; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.12.096
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In the present work advances and limitations in the application of Fe(III)-oxalate complexes (namely, [Fe(Ox)3 ] 3- ) to the photodegradation of a model persistent organic contaminant - 2, 4-dichlorophenoxybutanoic acid (2, 4-DB) in neutral aqueous solutions were systematically investigated for the first time. It has been shown that the efficiency of [Fe(Ox)3 ] 3- system greatly depends on the initial concentrations of oxalate ion due to the fast consumption of the ligand during photodegradation process leading to the formation of photochemically less active Fe(III) species. Efficiency of Fe(Ox)3 3− system normalized to UVA absorption at the excitation wavelength is practically independent on [Fe(III)]. Thus, it is highly probable that concentrations of Fe(III) as low as < 10 −5 M could be applied in water treatment procedures using reactors with very long optical path. The system also keeps high efficiency at low concentration of pollutant (<10 −5 M) though this results in higher relative consumption rate of Fe(III) and oxalate ions. Highlights: Advances and limitations of [Fe(Ox)3 ] 3- complex as a photodegradation agent at neutral pH were found. Optimal conditions for the photodegradation of persistent organic contaminant 2, 4-DB were determined. Fe(Ox)3 3− system keeps high initial efficiency at low concentrations of both pollutant and the complex. The prolonged photolysis of Fe(Ox)3 3− is useless due to the formation of less photoactive Fe(III) complexes.