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

ABSTRACT

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. ${\mathrm{S}\mathrm{O}}_4^{2-}$ ions had a relatively large impact on the Cr(VI) adsorption compared with other coexisting ions such as ${\mathrm{N}\mathrm{O}}_3^{-}$, Cl⁻ and ${\mathrm{H}}_2{\mathrm{P}\mathrm{O}}_4^{-1}$. 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.

KEYWORDS:

• Adsorption
• hexavalent chromium
• NH₂-MIL-101(Cr)
• polyethylenimine (PEI)
• water pollutant

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by Guangxi Province Natural Science Foundation of China [grant number 2018GXNSFDA281018] and the NSFC [grant number 51664002].

Notes on contributors

Zhenpeng Li

Zhenpeng Li is a Postgraduate of Guangxi University , Nanning, Guangxi, China. His research interest is in heavy metal adsorption.

Dongmei Yan

Dongmei Yan is a researcher at the Institute of Smart Agriculture, GIIT, Nanning, Guangxi, China. Her research interest is in agricultural environment and ecology.

Jun Li

Jun Li is a researcher at the Institute of Smart Agriculture, GIIT, Nanning, Guangxi, China. His research interest is in agricultural environment and ecology.

Ziwei Mai

Ziwei Mai is a researcher at the Institute of Smart Agriculture, GIIT, Nanning, Guangxi, China. His research interest is in agricultural environment and ecology.

Fuchuan Huang

Fuchuan Huang is a professor at the College of Mechanical Engineering, Guangxi University, Nanning, Guangxi, China. His research interest is in treatment and reuse of urban and industrial wastes.