Highly efficient hexavalent chromium removal on polyethylenimine@NH2-MIL-101(Cr) composite

Hexavalent chromium (Cr(VI)) is regarded as a water pollutant because of its high toxicity in aquatic environments. In this study, polyethyleneimine-functionalised NH2-MIL-101(Cr) (PEI@NH2-MIL-101(Cr)) was fabricated by a facile wet impregnation method, and its effectiveness at removing Cr(VI) from wastewater was systematically investigated. As suggested by the experimental findings, pH was a significant determinant of Cr(VI) uptake by the fabricated PEI@NH2-MIL-101(Cr). Preferable depiction of adsorption system was achievable with the Langmuir adsorption model and the pseudo-order 2 kinetic model. At 288, 298, and 308 K, the highest adsorbability values were 241.55, 310.56, and 408.16 mg g−1, respectively. Processes like electrostatic attraction, reduction and chelation helped promote the Cr(VI) elimination. SO42− ions had a relatively large impact on the Cr(VI) adsorption compared with other coexisting ions such as NO3−, Cl− and H2PO4−1. Because of its properties of high adsorption capacity and Cr(VI) detoxification, the potential of PEI@NH2-MIL-101(Cr) in the Cr(VI) elimination from wastewater appears to be promising.