Application of Electrochemical Degradation of Wastewater Composed of Mixtures of Phenol-Formaldehyde

摘要

The industrial wastewater from resin production plants contains as major components phenol and formaldehyde, which are traditionally treated by biological methods. As a possible alternative method, electrochemical treatment was tested using solutions containing a mixture of phenol and formaldehyde simulating an industrial effluent. The anode used was a dimensionally stable anode (DSA®) of nominal composition Ti/Ru_0.3Ti_0.7O_2, and the solution composition during the degradation process was analyzed by liquid chromatography and the removal of total organic carbon. From cyclic voltammetry, it is observed that for formaldehyde, a small offset of the beginning of the oxygen evolution reaction occurs, but for phenol, the reaction is inhibited and the current density decreases. From the electrochemical degradations, it was determined that 40 mA cm"2 is the most efficient current density and the comparison of different supporting electrolytes (Na_2SO_4, NaNO_3, and NaCl) indicated a higher removal of total organic carbon in NaCl medium.