Adsorption Performance of Cd(II) by Chitosan-Fe3O4-Modified Fish Bone Char

Abstract

In order to develop a low-cost, fast, and efficient adsorbent, the fish bone charcoal B600 prepared at 600 °C was modified by chitosan (Cs) and Fe3O4 to produce the material Cs-Fe3O4-B600. Results showed that Cs-Fe3O4-B600 had magnetic responsiveness and can achieve solid–liquid separation, macropores disappeared, pore volume and specific surface area are increased, and amino functional groups appear on the surface. The adsorption process of Cd(II) by Cs-Fe3O4-B600 conformed best to the pseudo-second order kinetics model and the Langmuir model, respectively. The behavior over a whole range of adsorption was consistent with chemical adsorption being the rate-controlling step, which is a very fast adsorption process, and the isothermal adsorption is mainly monolayer adsorption, which belongs to favorable adsorption. In addition, the saturated adsorption capacity obtained for the Cs-Fe3O4-B600 to Cd(II) was 64.31 mg·g−1, which was 1.7 times than B600. The structure and morphology of Cs-Fe3O4-B600 were characterized through SEM-EDS, TEM, FTIR, and XRD, indicating that the main mechanism of Cs-Fe3O4-B600 and Cd(II) is mainly the complexation of amino groups, and it also includes part of the ion exchange between Cd(II) and Fe3O4. Therefore, Cs-Fe3O4-B600 can be employed as an effective agent for remediation of Cd contaminated water.