PREPARATION OF CARBOXYL MODIFIED POLYACRYLONITRILE NANOFIBER AND ITS ADSORPTION PROPERTIES FOR Cd2+
PAN-COOH nanofiber membranes were successfully prepared by radical polymerization and electrospinning device,the structure of the fibrous membrane was characterized and analyzed with Fouriertransform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM).and the desorption ability of PAN-COOH and PAN for Cd2+was compared.The adsorption capacity of PAN-COOH-a and PAN-COOH-b increased by 65％and 95％compared with pure PAN.The thermodynamic and kinetic adsorption mechanism of PAN-COOH-b was studied,and the influence of metal ion concentration,pH value,temperature and cycle on Cd2+adsorption was explored.The thermodynamic results accorded with adsorption isotherm and the predicted theoretical maximum adsorption capacity is 204 mg·g-1.Kinetic studies shown the reaction follows pseudo-second-order rate equation,which is mainly controlled by chemistry and reaches equilibrium within 5 h,and the optimal adsorption conditions are pH=6,T=25 ℃,and metal ion concentration of 400 mg·L-1.Furthermore,the adsorption-desorption cycle experiments revealed that the PAN-COOH-b fiber membrane can still maintain 93％of the initial adsorption capacity after 4 cycles,and has a good cyclic utilization effect.The above results demonstrate that this material has great potential in the field of cadmium wastewater purification.
polyacrylonitrile modified with carboxylelectrospinning technologycadmiumadsorption
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