Electrochemical oxidation of reverse osmosis concentrate using a novel electrode: Parameter optimization and kinetics study

Pharmaceutical wastewater is difficult to be treated efficiently by the conventional biological wastewater treatment plant and reverse osmosis is a solution for this kind of wastewater pollution control. One limitation for RO application in pharmaceutical wastewater treatment is the treatment of RO concentrate. This work prepared a Co doped PbO2 anode and assessed the treatment of reverse osmosis concentrates with electrochemical oxidation process using this Co doped PbO2 anode. The operational parameters which have an influence on the electrochemical oxidation of quinoline, including the current density, the initial concentration of quinoline and the initial value of pH, were studied. The results revealed that the electrochemical degradation of quinoline followed the pseudo-first-order kinetics and the optimal removals of quinoline and COD were 100% and 59.35% after 120 min. The EE/O was calculated among all the experiments which showed that the Co doped electrode would greatly reduce the EE/O value. The degradation mechanism and kinetics were analyzed and the intermediates including kinds of organic acids generated during the process of electrolysis were analyzed. This paper can provide a technique reference for the reverse osmosis concentrate pollution control.