Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming 650500, China.
College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, China.
Sci Total Environ. 2021 Jun 1;771:145455. doi: 10.1016/j.scitotenv.2021.145455. Epub 2021 Jan 28.
The adsorption of ofloxacin (OFL) on oxidized activated carbon (AC) and carbon nanotube (CNT) are compared, focusing on the differences in carbon structures. Chemical oxidation of carbonaceous materials inhibited OFL adsorption to AC, but enhanced their adsorption to CNT. The higher number of oxygen-containing functional groups facilitated the interaction of the material with water molecules, causing the blockage of AC inner pore. However, the dispersion of oxidized CNT enhanced due to its increased hydrophilicity, resulting in the exposure of some new adsorption sites, as identified by the H NMR relaxometry measurement. The adsorption kinetics of OFL on AC indicated that the contributions of slow adsorption and equilibrium time increased after AC oxidation. However, the equilibrium time of the fast adsorption of OFL on CNT shortened after CNT oxidation. These results indicated that the pore of AC was blocked by water cluster and the accessibility of adsorption sites on oxidized CNT was enhanced due to dispersion. This study emphasizes that the structural differences among carbonaceous materials control the oxidation effects on their adsorption characteristics for OFL.
比较了氧化活性炭 (AC) 和碳纳米管 (CNT) 对氧氟沙星 (OFL) 的吸附，重点关注碳结构的差异。碳质材料的化学氧化抑制了 OFL 在 AC 上的吸附，但增强了其在 CNT 上的吸附。含氧官能团的数量越多，越有利于材料与水分子的相互作用，从而导致 AC 内孔堵塞。然而，氧化 CNT 的分散度增强，因为其亲水性增加，导致一些新的吸附位暴露，这可以通过 H NMR 弛豫测量来确定。OFL 在 AC 上的吸附动力学表明，AC 氧化后，缓慢吸附和平衡时间的贡献增加。然而，CNT 氧化后，OFL 在 CNT 上的快速吸附平衡时间缩短。这些结果表明，AC 的孔被水簇堵塞，而氧化 CNT 的分散度增加，导致吸附位的可及性增强。本研究强调，碳质材料的结构差异控制着氧化对其 OFL 吸附特性的影响。
