The Study Of Removing Cadmium,Copper And Methyl Orange From Aqueous Solution Using Titanium Net Coated With Single Walled Carbon Nanotubes As Electrode

The discharge of heavy metal and dyestuff is increasing with fast development of industry and threatening human health and ecological environment.At present,treatment methods for heavy metal,including chemical deposition,membrane separation etc and for dyestuff,including advanced oxidation process,adsorption etc have been widely used.However,their disadvantages,such as secondary pollution and high cost,are also serious.Electrochemical technique is a new method of wastewater treatment developed in recent years with some advantages,such as high removal efficiency,environmentally friendly and secondary pollution free,showing great potential in heavy metal and dyestuff wastewater treatment.As a new kind of carbon material,carbon nanotubes(CNTs)was discovered and developed in recent 30 years with the characteristics of high specific surface area,easy modification of surface and high conductivity.It has been widely used in the wastewater treatment.Titanium mesh is a common metal material with the features of stable chemical properties,corrosion resistant and high conductivity.Electrophoresis deposition method(EPD)was used to prepare titanium mesh electrodes coated with single walled carbon nanotubes,as SWCNTs@Ti Net.The performances of SWCNTs@Ti Net was studies by polarization curve and cyclic voltammeter curve.The electrochemical system equipped with SWCNTs@Ti Net electrodes was applied to removal cadmium,copper and methyl orange from aqueous solution,respectively.Effects of experimental parameters,including electrode assembling,solution pH,applied voltage and electrolyte concentration on cadmium,copper and methyl orange removal and removal mechanism were investigated.The rengeneration and reuse of SWCNTs@Ti Net as electrodes was studied.The study contents and results are the follows:Applied voltage 2.5 V.pH 8 and electrolyte at concentration NaNO3 20 g·L-1,were the optimal experimental conditions for cadmium removal.The optimal removal efficiency was 89.13%.The used SWCNTs@Ti Net electrode could be regenerated with acid rinse.The mechanism of cadmium(?)removal was the formation of a absorbed double layer and the formation of Cd(OH)2 on the electrode.Applied voltage 2.5 V,pH 6 and electrolyte at concentration NaNO3 6 g·L-1,were the optimal experimental conditions for copper removal.The optimal removal efficiency was 99.9%.The used SWCNTs@Ti Net electrode could be regenerated with acid rinse.The mechanism of copper(?)removal was the formation of a absorbed double layer and reduction of copper(?).Applied voltage 2.0 V,pH 2 and electrolyte at concentration Na2SO4 1g· L-1 were the optimal experimental conditions for methyl orange removal.The optimal removal efficiency was 99%.The used SWCNTs@Ti Net electrode could be regenerated with washing and recycle.