Electrochemical Degradation of P-nitrophenol on Fe-PTFE-nano-PbO_2/Ti Electrode

Electrochemical degradation of p-nitrophenol was studied.Using Fe-PTFE-nano-PbO2/Ti as anode and graphite as cathode,influence factors of p-nitrophenol degradation such as current density,initial p-nitrophenol concentration,supporting electrolyte concentration,initial pH were investigated.It was found that when the current density was higher,more·OH was generated which could enhance the removal efficiency.When p-NP concentration was lower,electrochemical degradation speed was faster than diffusion which resulted in a faster degradation speed,while when the concentration was higher,more refractory intermediates were generated,which were hard to resolve than p-NP,the apparent rate constant was lower.When Na2SO4 concentration was higher,the intermediates generated from SO42-owned the oxidation ability which could enhance the removal efficiency.When pH was lower,the oxygen overpotential decreased,and it was hard to have side reaction which benefited p-NP removal.Under the conditions of current density 20 mA/cm2,initial p-nitrophenol concentration 100 mg/L,supporting electrolyte Na2SO4 concentration 0.02 mg/L,initial pH 5.1,p-NP and COD removal efficiency were 99.23% and 77.38% respectively,and mineralization rate was high.