Porous Carbon Prepared From Corn Stover For Electrochemical Adsorption Of Copper Ions In Water

Water is the essential material basis for human survival.However,the fresh water resources on the earth that can be used for direct development and utilization are extremely scarce,and there are serious pollution phenomena.Among them,heavy metal pollution is a very common form of water pollution.However,the traditional heavy metal wastewater treatment methods have some problems,such as secondary pollution,poor effect,membrane pore blockage and so on.Capacitive deionization technology has been paid more and more attention because of its advantages such as high efficiency,low consumption and environmental friendliness.In this paper,porous carbon electrode materials were prepared from straw and applied to electrochemical adsorption of copper ions in water and removal of copper ions in simulated electroplating copper rinsing wastewater.Corn straw porous carbon(CSPC) was prepared by one-step carbonization method with corn straw as carbon source and KOH as activator.Through microscopic characterization and electrochemical performance test,it can be found that the CSPC material has a large number of micropores,the pore size distribution is more uniform,the specific surface area is larger(944 m²g^-1),and the surface contains rich oxygen-containing functional groups.These properties make the CSPC material have very good electrochemical adsorption performance.When the applied voltage is 0.8 V,the electrode spacing is 0.3 mm,and the circulating flow rate is 15m L min^-1,the CSPC electrode material shows the best electro adsorption effect.The removal rate of Cu²⁺is 74.6%,and the adsorption capacity is 6.17 mg g^-1.The main adsorption processes are surface adsorption and single electron layer adsorption.After repeated adsorption desorption cycle experiments,the removal performance of the electrode remained at about 95.24%,showing excellent cycle stability.The prepared straw based porous carbon electrode material was used to remove copper ions from simulated copper electroplating rinsing wastewater,and the CSPC electrode also showed good electro adsorption performance.The concentration of Cu²⁺in simulated copper rinsing wastewater is 100 mg L^-1,and CSPC-700-1:1electrode reaches the adsorption equilibrium after 100 min.The adsorption capacity of Cu²⁺is 7.43 mg g^-1 and the removal rate is 44.6%.The final concentration of Cu²⁺decreased to 1.5 mg L^-1 by replacing electrode plate and continuing the process of electric adsorption.