| Phenolic effluent,with a wide source and a large amount,has impacted seriously to humans,aquatic organisms and the ecological environment when the effluent directly discharges into water body.Heterogeneous Fenton-like reaction exhibits the advantages,such as simple equipment,mild reaction conditions,and low cost.Among the heterogeneous Fenton-like catalysts,Cu-based catalysts have received lots of attention due to high activity.However,the application of the Cu-based catalysts is still limited due to the poor stability of the catalysts.In response to the problems,the efficient and stable Cu-based catalysts,including other metal oxides,were developed in our study,and were characterized by SEM(Scanning electronic microscopy),EDS(Energy dispersive spectrometer)and XPS(X-ray photoelectron spectroscopy).The heterogeneous Fenton-like reaction for the degradation of phenol over the Cu-based catalysts was investigated under mild conditions near neutral pH.Phenol degradation efficiency and stability of the Cu-based catalysts were evaluated in one-stage and two-stage fixed bed reactors,respectively.The study could provide a theoretical guide and promote the application of the heterogeneous Fenton-like reaction for degrading wastewater.The Cu/Bi-Ce/Al2O3 catalyst showed good performance and stability in the Fenton-like reaction for the phenol degradation.In a one-stage fixed bed reactor,the phenol removal was 47.3%in the heterogeneous Fenton-like reaction over the Cu/Bi-Ce/Al2O3 catalysts udner the conditions([Phenol]0=100 mg/L,pH=6.25,[H2O2]0=30 mM,HRT=30 min,T=40℃).The leaching concentration of Cu2+was 0.87 mg/L in the solution in the reaction over the Cu/Bi-Ce/Al2O3 catalyst.Moreover,the leaching of Cu2+was not detected in the reaction over the Cu/Bi-Mg/Al2O3 catalyst which doped-alkaline earth metal Mg,while the degradation phenol of the catalyst was 40%.In the two-stage fixed bed reactor,the Cu/Bi-Ce/Al2O3 catalyst exhibited good catalytic performance and stability.The phenol degradation(79.9%)was obviously improved in the heterogeneous Fenton-like reaction over the Cu/Bi-Ce/Al2O3 as compared to the removal in the one-stage reactor under the same operating conditions.The Cu2+ leaching was 0.9 mg/L udner the conditions([Phenol]0=100 mg/L,pH=6.25,[H2O2]1=[H2O2]2=30 mM,HRT1=20 min,HRT2=10 min,T=40℃).Using the Cu/Bi-Mg/Al2O3,the phenol degradation efficiency was 74.1%,and the leaching of Cu2+slightly decreased to 0.8 mg/L.In the process of heterogeneous Fenton-like degradation of phenol over the Cu-based catalyst,the produced intermediates were mainly catechol and p-benzoquinone,and a small number of organic acids(such as oxalic acid,maleic acid,etc.).Organic matter and(?)in the actual water body had a great influence on the phenol degradation in the heterogeneous Fenton-like reaction over the Cu-based catalyst.The consumption reaction with reactive species between organic matter and(?)happened in the reaction.The main produced reactive species were 1O2 and O2-/HO2· in the heterogeneous Fenton-like reaction over the Cu-based catalysts. |
