Investigation of the Electrochemical Methylene Orange Effluent Degradation Using Graphite Battery Waste and Seawater

Electrochemical degradation using seawater and graphite electrodes from waste batteries for methylene orange (MO) dye degradation has been successfully carried out. Electrode characterization, electrolyte calibration, and dye degradation effectiveness with various voltages, pH, kinetics, and degradation reaction mechanisms were observed. Characterization showed a characteristic 2θ peak by X-ray diffractometer (XRD) at 26.5 °, and scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDX) showed the morphology of hollow grains with carbon (C) and oxygen (O) composition. In addition, scanning potentiometry showed the initiation of hypochlorite compound formation and MO degradation. Further study of degradation effectiveness showed optimal results at 3 volts and above voltages. Hypochlorous acid (HOCl) and hypochlorite ions (OCl-) from seawater are very effective oxidizing agents in acidic conditions compared to other pH conditions. Pseudo-first-order kinetics regulate the electron attack from the hypochlorite oxidizer (OCl-), the hydroxyl groups (•OH) from the seawater electrolysis mechanism with graphite electrode media on the reactive groups, the ring binding on MO, and the degradation. This indicates that the graphite electrode system used to reuse waste batteries and seawater has the potential to degrade waste dyes in aquatic environments. HIGHLIGHTS Electrochemical system with graphite electrode battery waste and seawater electrolyte. Characterization with XRD, SEM-EDX, spectrometry, and potentiometry. Analysis of the effect of voltage and pH treatment variation. Kinetic and degradation mechanism of methylene orange. GRAPHICAL ABSTRACT