| Phenolic wastewater is a kind of highly toxic and non-biodegradable industrial organic wastewater.To solve the challenging problems in phenolic wastewater treatment,a electrocatalytic membrane reactor(ECMR)was proposed with Ti02/Ti electrode membrane as anode and a stainless steel mesh as cathode.A plate Ti membrane was prepared by powder metallurgy,and the TiO2/Ti composite electrode membrane was prepared by sol-gel method or hydrothermal method.The structure and performance of electrode membrane were analyzed by Electron density balance,Aperture tester,X-ray diffraction,Field-emission scanning electron microscopy,X-ray photoelectron spectroscopy and Electrochemical workstation.The influence of 800 nm,3 ?m titanium powder and mixed powder of 800 nm ?3 ?m on the structure and properties of the plate Ti membrane was investigated.The experimental results showed that the porosity of the plate Ti membrane,prepared by the mass ratio of 800nm and 3?m titanium powder to 2:1,was 36.30%,and the pore size distribution was between the two others.To explore the influence of process parameters on the pore structure of the plate Ti membrane prepared with the mixed titanium powder,the response surface experiment of the process parameters on system optimization was used.The results showed that if the porosity of the plate Ti membrane prepared was more than or equal to 35%(scheduled),the the process parameters were T<906.67?,P<102.67 MPa,t<2.13 h,respectively.The significant order of the processing parameters to the porosity and the average pore size was as follows:sintering temperature(A-T)>molding pressure(B-P)>holding time(C-t).Three kinds of the plate Ti membrane were prepared with 800 nm titanium powder,3 ?m titanium powder and the mixed powder,respectively,and TiO2/Ti composite electrode membrane was prepared by sol-gel method.When plate Ti membrane were prepared with the mixed titanium powder,whose the mass ratio of 800 nm and 3 ?m titanium powder was 2:1,the membrane resistance of TiO2/Ti composite electrode membrane was the lowest.The electrode/solution interface charge transfer impedance was the samallest compared with the two other composite electrode membranes.Under the operating conditions:room temperature,current density of 0.32 mA·cm-2,residence time of 9.6 min and Na2SO4 electrolyte concentration of 15 g/L,the energy consumption of ECMR with TiO2/Ti prepared with mixed Ti powders was the lowest during the electrocatalytic degradation of 450 ml/L phenol wastewater,that is 0.604 kW·h/kgCOD,which were reduced by 37.47%,23.73%,respectively,comparing with two other composite electrode membranes.These composite electrode membranes prepared with three plate Ti membranes have little difference on the COD removal rate for phenol,which means the structure of the the plate Ti membrane has little effect on the electrocatalytic performance.The Ti plate membrane was prepared by mass ratio 2:1 with mixing 800nm and 3?m titanium powder,and the TiO2/Ti composite electrode membrane was prepared by hydrothermal method.The optimal scheme of nanoparticles-TiO2/Ti composite membrane and nanowires-TiO2/Ti composite membrane was determined.Compared with nanoparticles-TiO2/Ti composite electrode membrane,the nanowire-TiO2/Ti composite membrane electrode had larger specific surface area,smaller electrode/solution interface charge transfer impedance and higher diffusion mass transfer coefficient.In the process of electrocatalytic degradation of phenol wastewater,under the same condition operation,the phenol and COD removal rate of ECMR with nanoparticles-TiO2/Ti was 82.72%and 78.01%,and those of nanowires-TiO2/Ti composite electrode membrane were reduced by 10.21%and 9.44%,reached 92.13%and 86.15%,respectively.The energy consumption of ECMR with nanowires-TiO2/Ti was reduced by 12.5%comparing with that of nanopartieles-TiO2/Ti composite electrode membrane. |
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