Abstract:
In order to solve the water contamination arises from heavy metal Pb(II), β-cyclodextrin modified magnetic palm fiber biochar (β-CD@PFMBC) was prepared with palm fiber as raw material by chemical coprecipitation method for efficient removal of Pb(II) from aqueous solution. The structure and morphology of the material were characterized by FTIR, XRD, BET, SEM, Raman and VSM. The adsorption properties of Pb(II) were analyzed through single factor experiment. The adsorption mechanism and recycling of Pb(II) were also explored. The results show that the specific surface area and the number of surface functional groups of β-CD@PFMBC increased compared with the pristine biochar. The adsorption process of Pb(II) can be better described by both the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model, which indicates that the adsorption process is chemical adsorption and monolayer adsorption. According to the Langmuir isotherm model, the maximum theoretical adsorption capacity of β-CD@PFMBC at 303 K is 625.49 mg∙g
–1, which is significantly higher than that of the pristine biochar. Thermodynamic studies show that the adsorption is a spontaneous endothermic process. The oxygen-containing groups on the surface of β-CD@PFMBC produce surface complexation and electrostatic interaction with Pb(II). The removal ration remains above 79% after five cycles of adsorption-desorption. It can be expected that β-CD@PFMBC will be of potential application in removing of Pb(II) from aqueous solution.