Photoelectro-Fenton treatment of pesticide triclopyr at neutral pH using Fe(III)-EDDS under UVA light or sunlight

Autor(es)

Da Costa Soares, Izabelle C. ^{[1, 2]} ; Oriol, Roger ^[1] ; Ye, Zhihong ^{[1, 3]} ; Martinez-Huitle, Carlos A. ^[2] ; Cabot, Pere L. ^[1] ; Brillas, Enric ^[1] ; Sires, Ignasi ^[1]

Afiliação do(s) autor(es)

^[1] Univ Barcelona, Lab Electroquim Mat & Medi Ambient, Dept Quim Fis, Fac Quim, Marti & Franques 1-11, Barcelona 08028 - Spain

^[2] Univ Fed Rio Grande do Norte, Inst Quim, Labo Eletroquim Ambiental & Aplicada, BR-59072900 Natal, RN - Brazil

^[3] Univ Hong Kong, Dept Civil Engn, Environm Engn Res Ctr, Pokfulam, Hong Kong - Peoples R China

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 28, n. 19, SI, p. 23833-23848, MAY 2021.
• Citações Web of Science: 0

Resumo

One of the main challenges of electrochemical Fenton-based processes is the treatment of organic pollutants at near-neutral pH. As a potential approach to this problem, this work addresses the use of a low content of soluble chelated metal catalyst, formed between Fe(III) and ethylenediamine-N,N'-disuccinic (EDDS) acid (1:1), to degrade the herbicide triclopyr in 0.050 M Na2SO4 solutions at pH 7.0 by photoelectro-Fenton with UVA light or sunlight (PEF and SPEF, respectively). Comparison with electro-Fenton treatments revealed the crucial role of the photo-Fenton-like reaction, since this promoted the production of soluble Fe(II) that enhanced the pesticide removal. Hydroxyl radicals formed at the anode surface and in the bulk were the main oxidants. A boron-doped diamond (BDD) anode yielded a greater mineralization than an IrO2-based one, at the expense of reduced cost-effectiveness. The effect of catalyst concentration and current density on the performance of PEF with BDD was examined. The PEF trials in 0.25 mM Na2SO4 + 0.35 mM NaCl medium showed a large influence of generated active chlorine as oxidant, being IrO2 more suitable than RuO2 and BDD. In SPEF with BDD, the higher light intensity from solar photons accelerated the removal of the catalyst and triclopyr, with small effect on mineralization. A plausible route for the herbicide degradation by Fe(III)-EDDS-catalyzed PEF and SPEF is finally proposed based on detected byproducts: three heteroaromatic and four linear N-aliphatic compounds, formamide, and tartronic and oxamic acids. (AU)

• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático