Modification Of Carbon Fibers Reinforced The Adsorption Of Cu²⁺ And Its Simulation Study

With the widespread use of copper in industrial processes,the direct emission of a large amount of copper-containing wastewater causes hugely environmental destruction.The adsorption method is commonly used in industry to treat copper-containing wastewater,but the existing regeneration methods of adsorption materials are complicated to be operated,expensive,and easily cause secondary pollution to the environment.Therefore,many researchers were focused on absorbent materials which can efficiently treat copper-containning wastewater and avoid regeneration pollution.In this paper,carbon fibers as the absorbent materials were explored their treatment performances on copper ions.The hydrothermal regeneration performance of the carbon fibers was explored by molecular simulation which provides a strong support for the application of carbon fiber in wastewater treatment.In this paper,to evaluate the performances of carbon fibers disposing of copper-containing wastewater,the important effects,such as copper ion concentration,p H value and carbon fiber dosage,were investigated by domestic device.The results showed that copper ions in the solution can be preferably adsorbed on carbon fibers at some special facts.For example,the research system was under copper ion concentration of 30 mg/L,p H value of 5,carbon fiber dosage of 0.5 g per 100 m L solution.The carbon fibers can effectively resist the solution of 178.34 L/m² and adsorb copper ions of 5.15 mg/g,respectively.To enlarge the capacity of copper ions adsorbed on carbon fibers,the carbon fibers were oxidized by H₂O₂.Although the maximum adsorption of 16.3 mg/g was obtained,its hydrothermal regeneration was unsatisfactory.Considering poor hydrothermal regeneration,the models of carbon fibers with different functional groups,such as sulfonic acid group,amine group,carboxyl group,epoxy group,and hydroxyl group,were built to explore the major impacts on the Materials Studio software platform.Based on the Molecular Dynamic,the processes of copper ions adsorbed on carbon fibers and desorbed from carbon fibers were simulated.The calculation results showed that the adsorption between copper ions and hydroxyl or epoxy groups mainly depends on lone pair electrons.As a result,the adsorption needs lower adsorption energy.According to the simulation of the desorption process of copper ions from carbon fibers,the maximum values of the diffusion coefficients of the hydroxyl group and the epoxy group were 100°C and 110°C,which proved that increasing the content of hydroxyl group and the epoxy group could improve the hydrothermal regeneration performance of the carbon fibers.Based on the simulation results,carbon fibers continued to be reduced by NaBH₄ after oxidation for increasing the content of hydroxyl and epoxy groups on the surface of the carbon fibers.The experimental results showed that hydroxyl content on the carbon fibers surface was increased to 112 %.Meanwhile,hydrotherma regeneration efficiency of 74 % for the carbon fibers was maintained after 6 cycles.It further illustrates that the modified carbon fibers can efficiently remove copper ions from the solution,and restore its adsorption capacity by hydrothermal regeneration.