Anodic oxidation of ketoprofen on boron-doped diamond (BDD) electrodes. Role of operative parameters

Electrochemical oxidation is a promising technology to treatment of bio-refractory compounds. Anodic oxidation of Ketoprofen, a representative endocrine disrupting chemical, was carried out using boron-doped diamond (BDD) electrodes at galvanostatic mode. A design of experiments procedure has been carried out in order to optimize the process and study the interaction between the studied variables: pH, current (I), supporting electrolyte concentration, Na2SO4, and solution flow rate (Qv). The influence of current was the greatest in studied variables, the second one was the salt concentration and the third one was the flow rate. The fourth one, pH, does not present significant influence inside the region of the central composite orthogonal and rotatable design. ANOVA test reported significant for four of the fourteen involved variables. An optimum ketoprofen degradation, XK, of 100% was found at pH 3.99, Qv = 1.42 cm3 min−1, current density equal to 235 mA cm−2 and a supporting electrolyte concentration equal to 0.5 mol L−1.