Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite: Batch and column studies. (1st January 2023)

• Record Type: Journal Article
• Authors: Qin, Xiaopeng; Zhong, Xiaofei; Wang, Bin; Wang, Guangcai; Liu, Fei; Weng, Liping
• Is Part Of: Environmental pollution. Volume 316(2023)part 2
• Publication Date: 2023-01-01
• Subjects: Goethite -- Adsorption -- Levofloxacin -- Ofloxacin -- Enantiomer fraction (EF) -- Natural organic matter (NOM); Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.120542
• Languages: English
• ISSNs: 0269-7491

Abstract

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. Graphical abstract: Image 1 Highlights: Natural organic matter (NOM) promoted levofloxacin (LEV) and ofloxacin (OFL) adsorption. Adsorption enantioselectivity of LEV and OFL were only found at pH > 7. Preload NOM decreased transport of LEV and OFL in column studies. Adsorption of OFL on goethite-coated sand was more strongly than LEV.