Coupled effect of colloids and surface chemical heterogeneity on the transport of antibiotics in porous media

• Published in: The Science of the total environment 2020-04, Vol.713, p.136644-136644, Article 136644
• Main Authors: Xing, Yingna, Chen, Xin, Wagner, Regan E., Zhuang, Jie, Chen, Xijuan
• Format: Article
• Language: English
• Subjects: Adsorption; Anti-Bacterial Agents - chemistry; Antibiotics; Colloids; Humic Substances; Porosity; Silicon Dioxide; Surface chemical heterogeneity; Transport
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.136644

Release of antibiotics into the environment has caused ecological and human health concerns in recent years. However, little is known about their transport behaviors in chemically heterogeneous porous media. In this study, we investigated the coupled effects of surface chemistry and soil colloids on the transport of ciprofloxacin and tetracycline through sand under steady state saturated flow conditions. Both antibiotics had a much higher capacity of adsorption on soil colloids (17,500 mg/kg for ciprofloxacin and 8600 mg/kg for tetracycline) than on sand (5.11 mg/kg for ciprofloxacin and 2.80 mg/kg for tetracycline). However, ciprofloxacin adsorption increased to 8.91 mg/kg after the sand was coated with iron oxide and to 8.73 mg/kg after the sand was coated with humic acid. Tetracycline, adsorption increased to 7.99 mg/kg after sand was coated with iron oxide coated sand and to 8.35 mg/kg after the sand was coated with humic acid coated The high adsorption capacity of ciprofloxacin led to a recovery rate of