Sorption mechanism of enrofloxacin on humic acids extracted from Brazilian soils

• Published in: Environmental science and pollution research international Vol. 24; no. 19; pp. 15995 - 16006
• Main Authors: Martínez-Mejía, Mónica J., Sato, Isabela, Rath, Susanne
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2017; Springer Nature B.V
• Subjects: Adsorption; Antibiotics; Antimicrobial agents; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Brazil; Carbohydrates; Carboxylic acids; Cation exchange; Cation exchanging; Complexation; Contaminants; Earth and Environmental Science; Ecotoxicology; Enrofloxacin; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fluoroquinolones; Functional groups; Humic acids; Humic Substances; Ions; Ligands; Lignin; Magnetic resonance spectroscopy; NMR; Nuclear magnetic resonance; Organic matter; Phenols; Research Article; Soil; Soil contamination; Soil Pollutants; Sorption; Spectroscopic analysis; Spectroscopy; Veterinary medicine; Waste Water Technology; Water Management; Water Pollution Control; Brazil; Fluoroquinolone sorption on humic acids; Ionic and cation bridging; Veterinary drugs; Sorption mechanism; Humic acids from Brazilian soils
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-9210-3

Veterinary antimicrobials are emerging environmental contaminants of concern. In this study, the sorption of enrofloxacin (ENR) onto humic acids (HAs) extracted from three Brazilian soils was evaluated. HAs were characterized by elemental analysis and solid
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C nuclear magnetic resonance spectroscopy. The sorption of ENR onto HAs was at least 20-fold higher than onto the soils from which they were separated. Ionic and cation bridging are the primary interactions involved. The interactions driven by cation exchange are predominant on HAs, which appear to have abundant carboxylic groups and a relatively high proportion of H-bond donor moieties with carbohydrate-like structures. Interactions explained by cation bridging and/or surface complexation on HAs are facilitated by moieties containing conjugated ligands, significant content of oxygen-containing functional groups, such as phenolic-OH or lignin-like structures. HAs containing electron-donating phenolic moieties and carboxylic acid ligand groups exhibit a sorption mechanism that is primarily driven by strong metal binding, favoring the formation of ternary complexes between functional groups of the organic matter and drugs.