Relevance of adjuvants and additives of pesticide commercial formulation on the removal performance of glyphosate by electrochemically driven processes. (1st March 2019)

• Record Type: Journal Article
• Authors: Lima, Nayara Silva; Souza, Éverton Marinheiro; Torres, Nádia Hortense; Bergamasco, Rosângela; Marques, Maria Nogueira; Garcia-Segura, Sergi; Sanchez de Alsina, Odélsia Leonor; Cavalcanti, Eliane Bezerra
• Is Part Of: Journal of cleaner production. Volume 212(2019)
• Page Start: 837
• Page End: 846
• Publication Date: 2019-03-01
• Subjects: Herbicide -- Persistent organic pollutants -- Electrochemical advanced oxidation processes -- Mineralization; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2018.12.007
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Glyphosate is a broad-spectrum systemic herbicide widely used in crops. Contamination of groundwater and superficial water sources by glyphosate may suppose an environmental risk due to its chronic toxicity. In this frame, development of water treatment technologies to remove glyphosate is of high relevance. The objective of this work was to evaluate capabilities of electrochemical oxidation (ECO) as emergent environmental friendly technology. The effect of variation of current density ( j ), pH and initial concentration of supporting electrolyte was studied when employing DSA ® expanded anodes of Ti/Ru0.36 Ti0.64 O2 . Special attention was given to the influence of pH due to the characteristic speciation of glyphosate that may influence ECO performance. Almost complete mineralization (>90%) of pure glyphosate was attained after 3 h of ECO treatment with 0.15 M NaCl at 40 mA cm −2 and pH 3.0. Meanwhile, solely 60% of mineralization was achieved under identical conditions when treating commercial glyphosate pesticide products. Degradation by-products and yielded ionic species were identified by chromatography and chromatography mass spectrometry. A reaction sequence for glyphosate ECO mineralization was proposed. Highlights: Complete degradation of glyphosate by electrochemical driven processes. Additives and adjuvants in pesticide commercial formulation decrease performance. Additives react competitively with electrogenerated oxidants. Figures of merit show low electrical energy per order requirements. Description of glyphosate electrochemical mineralization pathway.