Study on a novel flow-through electrochemical reactor based on particles confinement and electrochemical enhancement.

The flow-through electrochemical reactor had attracted much attention in wastewater treatment because it can improve the mass transfer process of pollutants. However, its application was limited because the matched porous electrode was difficult to process, easy to be blocked and had insufficient treatment capacity. Therefore, a novel type of flow-through electrochemical reactor based on activated carbon particles was proposed in this study, which enhanced mass transfer and electrochemical process. The effects of process parameters such as voltage and particle dosage were also investigated. Compared with the traditional flow-through electrochemical reactor, the new electrochemical reactor with activated carbon particles layer improved the removal efficiency of RhB from 13.0 % to 97.9 % under the same operating conditions. A kinetic model based on the new reactor was established, which showed that the removal process of RhB conformed to the apparent first-order kinetic model. Meanwhile, the apparent first-order surface-induced adsorption reaction rate constant and electrochemical reaction rate constant were determined. In order to investigate the operation stability of the new reactor, six rounds of long-term experiments were carried out in this study. The results showed that the removal efficiency of RhB remained above 96.5 % during each round of experiments without blockage occurring. In the treatment of actual printing and dyeing wastewater, the new reactor could achieve a COD removal rate of 78.6 % after 8 reaction hours. Therefore, the flow-through electrochemical reactor combined with activated carbon particles layer had a good application prospect in the field of wastewater treatment.