p-Nitrophenol abatement by the combination of electrocatalysis and activated carbon

A novel process combining electrocatalysis and activated carbon (AC) in fluidization mode was presented for p-nitrophenol (PNP) abatement. The synergetic effect was found by comparing with the individual electrocatalysis and AC adsorption, and the synergetic factor (f) was calculated to be 139%. Such a one-step process could almost completely remove the PNP of initial concentration of 150 mg L−1 in no more than 30 min. The mechanism of synergetic effects was due to the formation of AC microelectrodes under the electric field. Activated carbon microelectrodes in fluidization mode could largely improve the PNP degradation adsorbed on the surface of AC. Activated carbon played the double role of adsorbent and catalyst. Furthermore, AC adsorption capacity could be partly regenerated during the electrocatalysis. Sparged with O2, the removal rate of PNP was almost enhanced to 150%, compared with N2 sparged at 10-min degradation. Activated carbon amount, liquid flow rate, current, run batches, initial PNP concentration, and sparged gas were investigated to find out the factors affecting PNP abatement. The combined process showed potential application for environmental remediation.