ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Integrated electrocoagulation–photoelectrocatalytic oxidation for effective treatments of aqueous solution bisphenol-A using green-synthesized ZnO nanoparticles

Maruthamuthu Govindaraj, Sham Babu, Ramasamy Rathinam, Vijayan Vasini, and Kaliyapillai Vijayakumar

Department of Chemistry, K.Ramakrishnan College of Technology (Autonomous), Samayapuram, Tiruchirappalli, India

E-mail: govindarajm.sh@krct.ac.in

Received: 11 April 2022  Accepted: 5 September 2022

Abstract:

In the present investigation, a combined approach of electrocoagulation followed by photoelectrocatalytic oxidation of aqueous bisphenol-A (BPA) solution using titanium electrode coated by mixed metal oxides (RuO₂/IrO₂/TaO₂) through green-synthesized ZnO nanocatalyst (NPs) was performed. The biosynthesized RF-ZnO NPs were confirmed as nanoparticles using UV–Vis, FTIR spectroscopy, BET analysis, SEM, EDAX, HR-TEM, and XRD analysis. In the primary treatment process, the aqueous BPA solution was treated by electrocoagulation. The efficient ZnO NPs photocatalytic agent was synthesized from Rubus fairholmianus root extract. The removal of BBA was achieved at 59.83% at 20 min of treatment time. After completion of the electrocoagulation process, a secondary treatment process of photoelectrocatalytic oxidation with different operating parameters was investigated. The complete mineralization of BBA could be attained at a 25 mA cm⁻² of current density at treatment time of 90 min by photoelectrocatalytic oxidation. With an aid of supporting electrolyte (NaCl) in the basic medium, BPA degradation rates were increased with increasing applied current. GC–MS analysis was used to investigate the by-products obtained by degradation and the results were matched with standard NIST database. The kinetic parameters for degradation were calculated, which were fitted well with the pseudo-first-order kinetic model.

Keywords: Endocrine-disrupting chemicals; Bisphenol-A (BPA); Integrated treatment; Electrocoagulation (EC); Photoelectrocatalytic (PEC) oxidation; Biosynthesized RF-ZnO nanoparticles (RF-ZnO NPs)

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02473-w

Chemical Papers 77 (1) 169–183 (2023)