Arsenic(V) Adsorption from Aqueous Solution on Magnetic Fe0.2(Co20Ni80)0.8 Alloy Porous Microfibers

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, microstructure, 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 nm 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 arsenic(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.