Removal of perfluorooctanoic acid via polyethyleneimine modified graphene oxide: Effects of water matrices and understanding mechanisms

Xiaobo Lei; Qiyu Lian; Xu Zhang; Tiejun Wang; Michael Gee; William Holmes; Shiwei Jin; Senthil Kumar Ponnusamy; Daniel Dianchen Gang; Mark E Zappi

doi:10.1016/j.chemosphere.2022.136379

Removal of perfluorooctanoic acid via polyethyleneimine modified graphene oxide: Effects of water matrices and understanding mechanisms

Chemosphere. 2022 Dec;308(Pt 2):136379. doi: 10.1016/j.chemosphere.2022.136379. Epub 2022 Sep 8.

Authors

Affiliations

¹ Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA; Center for Environmental Technology, The Energy Institute of Louisiana, University of Louisiana at Lafayette, P. O. Box 43597, Lafayette, LA, 70504, USA.
² Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA; Beijing International Scientific and Technological Cooperation Base of Water Pollution Control Techniques for Antibiotics and Resistance Genes, School of Civil Engineering, Beijing Jiaotong University, Shangyuancun, Beijing, 100044, PR China.
³ Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA; Nanyang Vocational College of Agriculture, Nanyang, 473000, PR China.
⁴ Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA; Department of Engineering, University of California, Berkeley, CA, 94720, USA.
⁵ Center for Environmental Technology, The Energy Institute of Louisiana, University of Louisiana at Lafayette, P. O. Box 43597, Lafayette, LA, 70504, USA; Department of Chemical Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA.
⁶ Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, 430074, China.
⁷ Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Tamil Nadu, India.
⁸ Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA; Center for Environmental Technology, The Energy Institute of Louisiana, University of Louisiana at Lafayette, P. O. Box 43597, Lafayette, LA, 70504, USA. Electronic address: daniel.gang@louisiana.edu.

PMID: 36088978
DOI: 10.1016/j.chemosphere.2022.136379

Abstract

This research aimed to evaluate the adsorption behaviors and mechanisms of perfluorooctanoic acid (PFOA) onto polyethyleneimine modified graphene oxide (GO-PEI) from aqueous solutions. The adsorption capacity was significantly improved by doping polyethyleneimine (PEI) onto graphene oxide (GO). The Brunauer-Emmett-Teller (BET) isotherm model was considered as the best isotherm model in describing the PFOA adsorption onto GO-PEI3 (w_PEI/w_GO = 3). GO-PEI3 exhibited high adsorption capacity (q_e = 368.2 mg/g, calculated from BET isotherm model) and excellent stability. The maximum monolayer amount of PFOA adsorption onto GO-PEI3 (q_m = 231.2 mg/g) was successfully evaluated. The calculated saturated concentration (C_s = 169.9 mg/L) of PFOA on GO-PEI3 closely agrees with its critical micelle concentration (CMC = 157.0 mg/L), suggesting the formation of multilayer hemi-micelles or micelles PFOA structures on the surface of GO-PEI3. PFOA adsorption onto GO-PEI3 was inhibited by several factors including: the presence of humic acid (HA) by competing with the adsorption sites, background salts through the double-layer compression effect, and the competition from soluble ions for the amine or amide functional groups on GO-PEI3. Finally, both the FT-IR and XPS results confirmed that the adsorption of PFOA onto GO-PEI3 was through electrostatic attraction and hydrophobic interaction (physical adsorption), but not chemical adsorption. This work provides fundamental knowledge both in understanding the adsorption behavior through the BET isotherm model and in developing a stable adsorbent for PFOA adsorption. In addition, the findings highlight the potential of PFOA remediation from wastewater systems using GO-PEI in engineering applications.

Keywords: Adsorption; Electrostatic attraction; Graphene oxide; Perfluorooctanoic acid; Polyethyleneimine.

MeSH terms

Amides
Amines
Caprylates
Carbonated Water*
Fluorocarbons
Graphite
Humic Substances
Micelles
Polyethyleneimine* / chemistry
Salts
Spectroscopy, Fourier Transform Infrared
Steam
Wastewater / chemistry
Water

Substances

Amides
Amines
Caprylates
Carbonated Water
Fluorocarbons
Humic Substances
Micelles
Salts
Steam
Waste Water
graphene oxide
Water
Graphite
Polyethyleneimine
perfluorooctanoic acid