Bimetal-oxide (Fe/Co) modified bagasse-waste carbon coated on lead oxide-battery electrode for metronidazole removal

Current study covers the preparation and application of a commercial modified lead oxide battery electrode (LBE) in electrochemical oxidation (ECO) of metronidazole (MNZ) in an aqueous phase. Modified electrode is prepared by doping of bimetal-oxide (Fe and Zn) nanoparticles (NPs) & single metal-oxide (Fe/Zn) on bagasse-waste carbon (bwc) which is further coated on LBE. The modified LBE electrode surface was examined for metal-oxide NPs through X-ray diffraction analysis (XRD). Different electrodes are prepared by varying combinations of two metal-oxide based on molar ratio and tested for electrochemical characterization and MNZ removal test. Based on large oxygen evolution potential in a linear sweep volumetry (LSV) analysis and high MNZ removal rate, the best electrode has been represented as Fe₁:Co₂-bwc/LBE which contains Fe & Co molar ratio of 1:2. Moreover, equilibrium attained at faster rate in degradation process of MNZ, where pseudo first order kinetics of 2.29 × 10^-2 min^-1 was obtained under optimized condition of (MNZ:100 mg/L, pH:7, CD: 30 mA/cm² and electrolyte: 0.05 M Na₂SO₄). Maximum MNZ removal, total organic carbon removal (TOC), mineralization current efficiency (MCE) & energy consumption (EC) of 98.7%, 85.3%, 62.2% & 96.143 kW h/kg-TOC removed are found in 180 min of treatment time for Fe₁:Co₂-bwc/LBE electrode. Accelerated service life test confirms that the stability of modified electrode is enhanced by 1.5 times compared to pristine LBE. Repeatability test confirms that modified LBE (Fe₁:Co₂-bwc/LBE) can be utilized up to 3 times.