Arsenic(V) Adsorption from Aqueous Solution on Magnetic Fe_(0.2)(Co_(20)Ni_(80)_(0.8) Alloy Porous Microfibers

摘要

The magnetic, nanocrystalline Fe_(0.2)(Co_(20) Ni_(80))_(0.8) alloy porous microfibers were prepared by the citrate gel thermal decomposition and reduction process. The morphology, chemical composition, mi-crostructure, and magnetic properties of the microfibers were investigated by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray, Brunauere-Emmette-Teller, and vibration sample magnetometer. The as-prepared magnetic, nanocrystalline Fe_(0.2)(Co_(20)Ni_(80))_(0.8) porous microfibers consisting of about 48 run grains are characterized by diameters of 1-4 μm, specific surface area of 17.73 m~2/g, and specific magnetization of 196.7 Am~2/kg. The arsenic(V) absorption on these magnetic Fe_(0.2)(Co_(20)Ni_(80))_(0.8) porous microfibers at room temperature was determined by the ICP-AES measurement of arsenic(V) in aqueous solution. The results show that the pseudo-first-order kinetic model is consistent with the arsenic(V) adsorption process and a good correlation coefficient (R~2=0.9862). By comparing among the Langmuir, Freundlich, Temkin, and Redlich-Peterson models for adsorption isotherms of arsenic(V) onto the magnetic Fe_(0.2)(Co_(20)Ni_(80))_(0.8) porous microfibers at room temperature, the Freundlich model and Redlich-Peterson model can be used to evaluate the arse-nic(V) adsorption isotherm at room temperature. The arsenic(V) equilibrium absorbance of the magnetic Fe_(0.2)(Co_(20)Ni_(80))_(0.8) porous microfibers is up to 1.9 mg/g when the initial arsenic(V) concentration is 1.0 mg/L in aqueous solution.