Electrochemical regeneration of granular activated carbon saturated with acid red 18 using a novel modified Ti/Co-MnO2 electrode

In this work, the electrochemical (EC) regeneration of granular activated carbon (GAC) saturated with Acid Red 18 (AR18) was investigated using a novel non-active anode of modified Co-MnO2 in a batch reactor. The study's main objective is the process modelling and optimising using the response surface methodology (RSM) based on a central composite design (CCD). The effective regeneration efficiency (RE) variables included: current density, electrolyte concentration and pH. The optimum values of current density, 0.18 A.cm(-2), electrolyte concentration, 0.22 mol.L-1, and pH, 2.35, were achieved. Additionally, under optimum conditions, a maximum RE of 88% was obtained. After three sequential adsorption-regeneration cycles, only 23 declination was observed in %RE, which confirmed the reuse feasibility of the regenerated GAC. The proposed model's fitness was checked by the determination coefficient (R-2 = 0.9914), which demonstrated the agreement between the quadratic model and the experimental results. Additionally, the energy consumption in the EC regeneration of saturated GAC under optimum conditions was calculated as 1.5 (kW.h.kg(-1)).