Antibiotics can alter the dispersibility and reroute the transport of microsized colloids

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 699; p. 134652
• Main Authors: Nguyen, Anh Q., Nguyen, Thu T.M., Phan, Duong T., Nguyen, Ngoc T.M., Nguyen-Thanh, Lan, Nguyen, Duc N., Nguyen, Anh D., Pham, Tien-Duc, Nguyen, Minh N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.10.2024
• Subjects: Antibiotic; Ciprofloxacin; Clay; Colloidal properties; Oxytetracycline; Sulfapyridine; Oxytetracycline; Clay; Antibiotic; Sulfapyridine; Ciprofloxacin; Colloidal properties
• ISSN: 0927-7757
• DOI: 10.1016/j.colsurfa.2024.134652

Antibiotics occur ubiquitously in natural aquatic and sediment environments, and they share the same transport routes with many other colloid particles such as minerals and oxides. However, their potential colloidal interactions are poorly understood. This work is a rapid communication of the colloidal behavior of different minerals and organic colloids (< 5 µm), i.e., haematite, goethite, bentonite, kaolinite, biochar, lateritic-, kaolinitic- and illitic soil clays, with the effects of antibiotics, i.e., oxytetracycline (OTC), sulfapyridine (SPD) and ciprofloxacin (CPX) with the purpose of providing a robust transportability prediction for these constituents. The zeta potential (ζ) and hydrodynamic size (dh) of antibiotic-mineral colloid suspensions were tracked over a pH range from ∼3 to ∼9, and then coupled with colloidal dynamic data provided by test tube experiments. The antibiotics used were found to vary ζ of colloids to different extents, hence they modified colloidal dynamics of colloids. Specifically, CPX with the concentration range from 10 to 40 mg L−1 resulted in drastic increases in ζ and counteracted the dispersion of colloids (especially lateritic soil clay), while OTC and SPD at the concentration ranges of 2.5–20 mg L−1 and 10–40 mg L−1 (respectively) showed minor effects. This suggests that the selective sorption of colloids for cationic antibiotics may induce dispersive changes, result in a delayed transport of cationic antibiotics and eventually reroute the transport of colloids. The observed phenomena for these used colloids and antibiotics can empirically exemplify what are happening in natural aquatic and sediment environments; and the role of mineral colloids as either carriers or barriers for the possible terrestrial-to-ocean transports of antibiotics worldwide needs to be highlighted. [Display omitted]