Insight into the adsorption of magnetic microspheres with large mesopores: Tailoring mesoporous structure and ethylenediamine functionalization for ultrahigh Congo red removal

In this paper, ethylenediamine (EDA)-functionalized magnetic microspheres with high specific surface areas and large mesopores were synthesized and optimized towards efficient removal of Congo red (CR) from wastewater. The optimal adsorbent FSN-2, which could be magnetically recovered, possessed an ultrahigh CR adsorption capacity of 1662 mg/g with good regeneration and reusability. The mechanisms of CR adsorption onto FSN-2 could be mainly explained by electrostatic attraction and hydrogen bonding.