Mechanism of photochemical degradation of Fe(III)-EDDS complex

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2020-08, Vol.399, p.112646, Article 112646
• Main Authors: Jaber, S., Leremboure, M., Thery, V., Delort, A.-M., Mailhot, G.
• Format: Article
• Language: English
• Subjects: Chemical Sciences; EDDS; Iron complex; Mass spectrometry; Oxidation; Photochemistry; Radical chemistry
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2020.112646

[Display omitted] •Fe(III)-EDDS complex is decomposed via a LMCT process under solar irradiation•EDDS degradation products are identified by HPLC-HRMS•Mechanisms with peroxy radicals can explain the formation of the identified products•EDDS is transformed into shorter oxidized products easily biodegradable•EDDS can be involved in AOPs used for water treatment without risk for environment In this work, we investigated the photochemical degradation of the complex Fe(III)-EDDS which is increasingly used in studies of advanced oxidation processes. After irradiation of the aqueous solution, HPLC-HRMS analyses are used to identify the degradation products of EDDS. Six different products are separated and identified with specific chemical formulas. Proposed mechanisms based on the initial photo-redox process can explain the formation of all the products. They correspond to oxidized products with a shorter carbon chain and aldehyde and/or carboxylic acid functions. Among, them the formation of formaldehyde is also proposed in the mechanisms. This study is the first one that identifies degradation products of Fe(III)-EDDS complex and proposes a complete mechanism of degradation that can be applied for other iron complexes.