Improvement of electrochemical wastewater treatment through mass transfer in a seepage carbon nanotube electrode reactor.

A seepage carbon nanotube electrode (SCNE) reactor was designed in order to facilitate contaminant mass transfer from bulk solution to the electrode surface, therefore to break the high cost bottleneck of electrochemical wastewater treatment. The innovative concept behind the reactor design is that the overall mass transfer would be significantly improved via contaminant migration through the porous carbon nanotube electrode. It was found out that the surface diffusivity D(s,i) in the external film was the controlling coefficient for electrochemical treatment, and the proposed process could improve the overall mass transfer coefficient by 116-161% compared with conventional electrochemical reactors under the same conditions. The research also showed that the current efficiency of the SCNE reactor was 340-519% higher than that of conventional reactors, and the energy consumption to mineralize the same amount of organics was only 16.5-22.3% of the conventional reactors. Also, the influences of potential, pH, and electrolyte concentration were investigated to optimize the operating parameters for the SCNE reactor. These results show that the SCNT reactor is promising because of its energy efficiency and has potential for application in wastewater treatment