Nanostructured electrochemical sensor applied to the electrocoagulation of arsenite in WWTP effluent. (November 2022)

• Record Type: Journal Article
• Authors: Piña, Samuel; Sandoval, Miguel A.; Jara-Ulloa, Paola; Contreras, David; Hassan, Natalia; Coreño, Oscar; Salazar, Ricardo
• Is Part Of: Chemosphere. Volume 306(2022)
• Publication Date: 2022-11
• Subjects: Arsenic elimination -- Electrocoagulation -- Electrochemical sensor -- Wastewater treatment -- Environmental pollutants; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135530
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: A sensitive electroanalytical method for the determination of arsenite, based on a heterostructure of aminated multiwalled carbon nanotubes and gold nanoparticles, was applied in an electrocoagulation (EC) treatment for the elimination of arsenite. A sensitive quantitative response was obtained in the determination of As 3+ in a secondary effluent from a wastewater treatment plant from Santiago (Chile). The preconcentration stage was optimized through a Central Composite Face design, and the most sensitive peak current was obtained at 200 s and −600 mV of time and accumulation potential, respectively, after a differential pulse voltammetry sweep. Electroanalytical determination was possible in an interval between 42.89 and 170.00 μg L −1 with a detection limit of 0.39 μg L −1, obtaining recoveries over 99.1%. The developed method was successfully applied in an electrocoagulation treatment to remove 250 μg L −1 of arsenite from a polluted effluent in a batch system. Complete arsenite removal was achieved using a steel EC system with a current density of 6.0 mA cm −2 in less than 3 min of treatment. Highlights: A new electrochemical sensor based on GCE modified with MWCNT-NH2 /AuNP was developed for quantification of As 3+ . Arsenite quantification using the new sensor in real wastewater showed high sensitivity and good LD. Total elimination of arsenite was reached by electrocoagulation in real WWTP effluent. Fast quantification of arsenite during electrocoagulation was possible using the electrochemical sensor.