Removal of Cd(II) and anthracene from water by 13-cyclodextrin functionalized magnetic hydrochar: Performance, mechanism and recovery

Magnetic hydrochar modified by 13-cyclodextrin (13-CD) described as 13-CD@MHC was successfully synthesized and applied to simultaneous removal of cadmium (Cd) and anthracene (ANT). Characterizations attested the grafting of 13-CD groups onto 13-CD@MHC with excellent magnetism. Moreover, the 13-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 13-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 13-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 13-CD@MHC dropped slightly after stepwise desorption, suggesting the 13-CD@MHC as a high-performance adsorbent for heavy metals and PAHs elimination from wastewater.

Automated summary

The magnetic hydrochar modified by 13-cyclodextrin showed excellent performance in the simultaneous removal of cadmium and anthracene. It exhibited fast adsorption equilibrium, high maximum monolayer binding capacity, and effective avoidance of competitive adsorption behavior between the two contaminants.