Study and actual application of the electrochemical reactor in flow-through mode based on channel confinement.

ABSTRACT

The method of enhancing mass transfer and improving reaction efficiency by confinement has attracted much attention in the electrochemical research field. In this research, to make low diffusion-limited electrochemical reactors fieldable, a new electrochemical reactor in flow-through mode was established with the mass-produced Ti/RuO2-IrO2 felt fibers as the electrodes. The effects of voltage, current, and electrode thickness were explored in this study. When the flow mode was switched from flow-by to flow-through, the single-pass degradation effect of rhodamine B rose from 4.4% to 74.8% under the same operating conditions. Meanwhile, a mass transfer model was established based on the results of removal efficiency and electrode channel parameters. The model was in good agreement with the new electrode parameters verification (R2 > 0.970). With this model, it could derive specific results on the effect of pore size change on the treatment effect. The impact of enhancing mass transfer by confining the pore sizes is most clearly gained at a certain range (less than 100 µm). Furthermore, a pilot-scale electrochemical reactor in flow-through mode was built, and excellent performance was shown in the treatment of actual waste leachate. The removal efficiencies of total nitrogen, ammonia, and nitrate were 80.9%, 88.6%, and 64.5% in 30 min, respectively. It will be a promising technology with good prospect.