Experimental-design-guided approach for the removal of atrazine by sono-electrochemical-UV-chlorine techniques

Author(s)

Pinto, Camila Ferreira ^[1] ; Antonelli, Raissa ^[1] ; de Araujo, Karla Santos ^{[1, 2]} ; de Toledo Fornazari, Ana Luiza ^[2] ; Fernandes, David Maikel ^{[2, 3]} ; Granato, Ana Claudia ^[2] ; Azevedo, Eduardo Bessa ^[4] ; Pointer Malpass, Geoffroy Roger ^{[1, 2]}

Affiliation

^[1] Univ Fed Triangulo Mineiro, Multicentr Postgrad Program Chem Minas Gerai, Av Doutor Randolfo Borges Jr, 1400 Univerdecidade, BR-38064200 Uberaba, MG - Brazil

^[2] Univ Fed Triangulo Mineiro, Profess Masters Program Technol Innovat, Av Doutor Randolfo Borges Jr, 1250 Univerdecidade, BR-38064200 Uberaba, MG - Brazil

^[3] Univ Uberaba Uniube, Av Nene Sabino 1801, BR-38055500 Uberaba, MG - Brazil

^[4] Univ Sao Paulo, Sao Carlos Inst Chem, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ENVIRONMENTAL TECHNOLOGY; v. 40, n. 4, p. 430-440, 2019.
• Web of Science Citations: 1

Abstract

The aim of the present study was to investigate the electrochemical formation of free chlorine species (HOCl/ClO-) and their subsequent use for the degradation of the pesticide atrazine. Initially, the process of electrochemical-free chlorine production was investigated using a bench-scale electrochemical flow-cell. The most significant variables (electrolyte concentration ({[}NaCl]) and inter-electrode gap) of the process were obtained using a 2(3) factorial design and the optimum process conditions (1.73molL(-1) and 0.56cm) were determined by a central composite design. Following optimization of free chlorine production, three degradation techniques were investigated, individually and in combination, for atrazine degradation: electrochemical, photochemical and sonochemical. The method using the techniques in combination was denominated sono-photo-assisted electrochemical degradation. Constant current assays were performed and the sono-photo-assisted electrochemical process promoted more efficient removal of atrazine, achieving total organic carbon removal of approximate to 98% and removal of atrazine to levels below the detection limit (>99%) in under 30min of treatment. Furthermore, the combination of three techniques displayed lower energy consumption, and phytotoxicity tests (Lactuca sativa) showed that there was no increase in toxicity. (AU)

• FAPESP's process: 14/02739-6 - Water reuse in irrigation and aquaculture: inactivation of pharmaceuticals and endocrine disruptors by solar photo-fenton
• Grantee: Eduardo Bessa Azevedo
• Support Opportunities: Regular Research Grants