Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite: Batch and column studies

Xiaopeng Qin; Xiaofei Zhong; Bin Wang; Guangcai Wang; Fei Liu; Liping Weng

doi:10.1016/j.envpol.2022.120542

Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite: Batch and column studies

Environ Pollut. 2023 Jan 1;316(Pt 2):120542. doi: 10.1016/j.envpol.2022.120542. Epub 2022 Oct 31.

Authors

Xiaopeng Qin¹, Xiaofei Zhong², Bin Wang³, Guangcai Wang⁴, Fei Liu⁴, Liping Weng⁵

Affiliations

¹ Technical Centre for Soil, Agricultural and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China; State Key Laboratory of Environmental Criteria and Risk Assessment, Institute of Soil and Solid, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China. Electronic address: qinxp@craes.org.cn.
² State Key Laboratory of Environmental Criteria and Risk Assessment, Institute of Soil and Solid, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; Beijing Key Laboratory of Water Resources and Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, PR China.
³ Technical Centre for Soil, Agricultural and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China; State Key Laboratory of Environmental Criteria and Risk Assessment, Institute of Soil and Solid, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China.
⁴ Beijing Key Laboratory of Water Resources and Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, PR China.
⁵ Department of Soil Quality, Wageningen University P.O. Box 47, 6700 AA, Wageningen, the Netherlands.

PMID: 36328279
DOI: 10.1016/j.envpol.2022.120542

Abstract

Adsorption and transport of levofloxacin (LEV) and ofloxacin (OFL) enantiomers in a matrix containing goethite and natural organic matter (NOM) were investigated using batch and column experiments. In batch studies, competition and enantioselectivity were observed in the adsorption of LEV and OFL. Enantioselectivity upon adsorption was investigated by comparing changes in the enantiomer fraction (EF) (the ratio of LEV to the sum of LEV and OFL remaining in the solution) after and before adsorption. At pH < 7, there was hardly any selectivity in adsorption of OFL and LEV to goethite. At pH > 7, OFL showed a stronger adsorption than LEV to goethite, and this preference remained when NOM samples of Leonardite humic acid (LHA) and Elliott Soil fulvic acid (ESFA) were added. However, when Suwannee River NOM (SRNOM) was added, the preference was reversed, and LEV was adsorbed more strongly. In single systems, the presence of different types of NOM increased adsorption of LEV and OFL, especially LEV. In column studies, preloaded NOM decreased the transport of LEV and OFL through goethite-coated sand. The EF values in the effluent increased with retention time and reached the largest values (0.59-0.72) at around 1.5 pore volume (PV), and then decreased again, reaching a stable value at 5.0-30.0 PV. Both batch and column experiments showed that, fractionation of LEV and OFL occurred during adsorption and transport in the presence of NOM-goethite complexes, which would eventually affect their environmental fate.

Keywords: Adsorption; Enantiomer fraction (EF); Goethite; Levofloxacin; Natural organic matter (NOM); Ofloxacin.

MeSH terms

Adsorption
Humic Substances / analysis
Iron Compounds* / chemistry
Levofloxacin* / chemistry
Ofloxacin

Substances

goethite
Levofloxacin
Ofloxacin
Iron Compounds
Humic Substances