MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China; Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China.
MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China; Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China.
J Environ Sci (China). 2022 Aug;118:46-56. doi: 10.1016/j.jes.2021.08.052. Epub 2022 Jan 10.
The adsorption behaviors of ciprofloxacin (CIP), a fluoroquinolone antibiotic, onto goethite (Gt) in the presence of silver and titanium dioxide nanoparticles (AgNPs and TiONPs) were investigated. Results showed that CIP adsorption kinetics in Gt with or without NPs both followed the pseudo-second-order kinetic model. The presence of AgNPs or TiONPs inhibited the adsorption of CIP by Gt. The amount of inhibition of CIP sorption due to AgNPs was decreased with an increase of solution pH from 5.0 to 9.0. In contrast, in the presence of TiONPs, CIP adsorption by Gt was almost unchanged at pHs of 5.0∼6.5 but was decreased with an increase of pH from 6.5 to 9.0. The mechanisms of AgNPs and TiONPs in inhibiting CIP adsorption by Gt were different, which was attributed to citrate coating of AgNPs resulting in competition with CIP for adsorption sites on Gt, while TiONPs could compete with Gt for CIP adsorption. Additionally, CIP was adsorbed by Gt or TiONPs through a tridentate complex involving the bidentate inner-sphere coordination of the deprotonated carboxylic group and hydrogen bonding through the adjacent carbonyl group on the quinoline ring. These findings advance our understanding of the environmental behavior and fate of fluoroquinolone antibiotics in the presence of NPs.
在银和二氧化钛纳米粒子（AgNPs 和 TiONPs）存在的情况下，研究了环丙沙星（CIP），一种氟喹诺酮类抗生素，在针铁矿（Gt）上的吸附行为。结果表明，Gt 中有无 NPs 存在时，CIP 的吸附动力学均遵循准二级动力学模型。AgNPs 或 TiONPs 的存在抑制了 Gt 对 CIP 的吸附。由于 AgNPs 的存在，抑制 CIP 吸附的量随着溶液 pH 值从 5.0 增加到 9.0 而降低。相比之下，在 TiONPs 存在下，在 pH 值为 5.0∼6.5 时，Gt 对 CIP 的吸附几乎不变，但随着 pH 值从 6.5 增加到 9.0 而降低。AgNPs 和 TiONPs 抑制 Gt 吸附 CIP 的机制不同，这归因于柠檬酸根的包裹导致 AgNPs 与 CIP 竞争 Gt 上的吸附位点，而 TiONPs 可以与 Gt 竞争 CIP 的吸附。此外，CIP 通过涉及去质子化羧酸基团的双齿内球配位和通过喹啉环上相邻羰基的氢键形成的三齿络合物被 Gt 或 TiONPs 吸附。这些发现提高了我们对氟喹诺酮类抗生素在 NPs 存在下的环境行为和归宿的理解。
