Role of electrolyte on anodic mineralization of atenolol at boron doped diamond and Pt electrodes

Anodic oxidation of atenolol, known as -blocker, has been investigated using boron-doped diamond(BDD) and Pt electrodes. The mineralization trend of atenolol in the presence of NaCl, Na2SO4 and NaNO3 was followed using total organic carbon analyzer. The disappearance of chloride ions and generation of active chlorine (Cl2, HOCl, OCl−) were analysed by argentometric and iodometric methods, respectively. The BDD anode was found to be effective in the presence of Na2SO4 whereas Pt yields better removal in the presence of NaCl. The initial concentration of NaCl and applied current density on the mineralization of atenolol were found to be significant for both BDD and Pt anodes. These results are explained in
terms of electrogenerated oxidants such as •OH, SO4•−, S2O8
2−, Cl2, HOCl and OCl−. The evolution of chlorine at BDD and Pt with respect to NaCl concentration was studied by means of cyclic voltammetric technique. Though the rate of mineralization was observed to be initially higher in the presence of Pt anode, the overall rate of mineralization is more or less similar beyond 15 h of electrooxidation. The slow degradation at the later stages of electrooxidation was attributed to the presence of residual chlorinated organic compounds which are very refractive. The complete mineralization was achieved in the presenceof Na2SO4 using BDD as anode.