TEPA modified magnetic cellulose nanocrystals for efficient and highly selective removal of Cr(VI) from...

Efficient and highly selective elimination of Cr(VI) from electroplating effluent with complex nature is still very meaningful and challenging. Here, based on the mechanism of selective adsorption, an amino-functionalized cellulose-based magnetic adsorbent (Fe₃O₄@CNC@TEPA) was designed with efficient and cost-effective. The adsorbent base material cellulose nanocrystals (CNC) was combined with a magnetic core (Fe₃O₄) by co-precipitation, and then the selective functional monomer tetraethylenepentamine (TEPA) was grafted onto the CNC surface in large quantities under the action of the cross-linking agent epichlorohydrin (ECH). High density amino acid protonation under acidic conditions makes the surface of the material positively charged, which leads to fast and accurate adsorption of Cr(VI), and this material shows excellent adsorption performance with the presence of high concentrations of coexisting ions. Characterization and DFT computational analysis demonstrated that the excellent selectivity and adsorption properties were mainly attributed to the electrostatic attraction, redox and complexation of Cr(VI) by abundant amino groups. In particular, the removal of Cr(VI) by Fe₃O₄@CNC@TEPA was maintained at a high level in the treatment of simulated electroplating wastewater from various water matrices. Overall, Fe₃O₄@CNC@TEPA is a potential adsorbent for the effective elimination of Cr(VI)-containing electroplating effluent.