Energy-efficient removal of carbamazepine in solution by electrocoagulation-electrofenton using a novel P-rGO cathode

摘要

In this study,carbamazepine(CBZ)decay in solution has been studied by coupling electro-coagulation with electro-Fenton(EC-EF)with a novel P-rGO/carbon felt(CF)cathode,aiming to accelerate the in-situ generation of·OH,instead of adding Fe2+and H2O2.Firstly,the fabri-cated P-rGO and its derived cathode were characterized by XRD,SEM,AFM,XPS and electro-chemical test(EIS,CV and LSV).Secondly,it was confirmed that the performance in removal efficiency and electric energy consumption(EEC)by EC-EF(kobs=0.124 min^(-1),EEC=43.98 kWh/kg CBZ)was better than EF(kobs=0.069 min^(-1),EEC=61.04 kWh/kg CBZ).Then,P-rGO/CF(kobs=0.248 min^(-1),EEC=29.47 kWh/kg CBZ,CE=61.04%)showed the best performance in EC-EF,among all studied heteroatom-doped graphene/CF.This superior performance may be associated with its largest layer spacing and richest C=C,which can promote the electron transfer rate and conductivity of the cathode.Thus,more H2O2 and·OH could be produced to degrade CBZ,and almost 100%CBZ was removed with kobs being 0.337 min^(-1) and the EEC was only 24.18 kWh/kg CBZ,under the optimal conditions(P-rGO loading was 6.0 mg/cm^(2),the current density was 10.0 mA/cm^(2),the gap between electrode was 2.0 cm).Additionally,no matter the influent is acidic,neutral or alkaline,no additional pH adjustment is required for the effluent of EC-EF.At last,an inconsecutive empirical kinetic model was firstly estab-lished to predict the effect of operating parameters on CBZ removal.