Removal of Cd(Ⅱ) and anthracene from water by β-cyclodextrin functionalized magnetic hydrochar: Performance, mechanism and recovery

Abstract

Magnetic hydrochar modified by β-cyclodextrin (β-CD) described as β-CD@MHC was successfully synthesized and applied to simultaneous removal of cadmium (Cd) and anthracene (ANT). Characterizations attested the grafting of β-CD groups onto β-CD@MHC with excellent magnetism. Moreover, the β-CD@MHC could eliminate Cd(II) and ANT during an extensive pH scope, and presented fast adsorption equilibrium in 60 min and 80 min for Cd(II) and ANT, respectively. And the β-CD@MHC possessed prominent adsorption properties with maximum monolayer binding of 47.28 mg/g for Cd(II), and corresponding heterogeneous uptake of 60.27 mg/g concerning ANT. Furthermore, the β-CD@MHC could effectively avoid the competitive behavior between Cd(II) and ANT mainly due to complexation and electrostatic attraction effects for capturing Cd(II), and host-guest interaction in the removal of ANT. Additionally, the binding of Cd(II) and ANT onto β-CD@MHC dropped slightly after stepwise desorption, suggesting the β-CD@MHC as a high-performance adsorbent for heavy metals and PAHs elimination from wastewater.

Keywords: Adsorption; Anthracene; Cd(II); Hydrochar; β–cyclodextrin.