Affordable Access

deepdyve-link
Publisher Website

Effects of Al substitution on sorption of diclofenac to Fe(III) (hydr)oxides: roles of phase transition and sorption mechanisms.

Authors
  • Bahashi, Jiayinaguli1
  • Bi, Erping2
  • 1 School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environmental Engineering, and MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China. , (China)
  • 2 School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environmental Engineering, and MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China. [email protected] , (China)
Type
Published Article
Journal
Environmental Science and Pollution Research
Publisher
Springer-Verlag
Publication Date
Mar 01, 2022
Volume
29
Issue
15
Pages
21314–21327
Identifiers
DOI: 10.1007/s11356-021-16992-8
PMID: 34761316
Source
Medline
Keywords
Language
English
License
Unknown

Abstract

Fe(III) (hydr)oxides commonly contained many metal impurities such as Al. The incorporation of Al might change the properties of minerals and consequently affect sorption behaviors of pollutants with polar functional groups (e.g., diclofenac (DCF)). In this study, batch experiments and microscale characterization were conducted to investigate the DCF sorption mechanisms to goethite and Al-substituted minerals. Goethite and Al-substituted products (including Al-goethite, Al-goethite-hematite, and Al-hematite) were synthesized with different Al contents (i.e., 0%, 5%, 10%, and 15% (in mol)) by co-precipitation method. Due to difference of ionic radius between Al and Fe and formation of excessive -OH, Al substitution resulted in deviation of cell parameters from the Vegard line. Al substitution caused increasing -OH in Al-goethite and phase transformation caused decreasing -OH in Al-hematite. The total -OH in minerals was positively related to DCF sorption capacity. In the lower initial concentration range (0.4-9 mg/L), the sorption distribution coefficient (Kd) values of goethite, Al-goethite, and Al-hematite were 21.98, 22.25, and 21.18 L/kg, respectively. Desorption characteristics and ion strength effects indicated that DCF sorption to minerals occurred mainly through outer-sphere complexation. Fourier transform infrared analyses revealed that H-bonds could be formed through -OH of minerals and -COOH of DCF, and the H-bond strength on Al-hematite was stronger than that on goethite/Al-goethite. In the normal environmental pH (e.g., 6.0 to 8.0), Kd values of DCF decreased linearly with increasing pH. These findings are helpful for understanding of DCF migration in environment involving Al-substituted minerals. © 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Report this publication

Statistics

Seen <100 times