Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China.
Institute of Coastal Environmental Pollution Control, Ministry of Education Key Laboratory of Marine Environment and Ecology, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266100, China.
Environ Pollut. 2023 Jan 1;316(Pt 1):120572. doi: 10.1016/j.envpol.2022.120572. Epub 2022 Nov 3.
Various hydrogen bonds, especially charge-assisted hydrogen bond (CAHB), is considered as one of vital mechanisms affecting the environmental behavior and risk of pharmaceutical contaminants (PCs). Herein the sorption/desorption of three PCs including clofibric acid (CA), acetaminophen (ACT), and sulfamerazine (SMZ) on three Oxygen-rich (O-rich) nanoparticles (nano-silica: Nano-SiO, nano-alumina: Nano-AlO, and oxidized carbon nanotubes: O-CNTs) were investigated to explore the effect of various hydrogen bonds with different strengths on environmental behaviors of PCs. The results indicated that although solvent-assisted CAHB, solvent-uninvolved CAHB, and ordinary hydrogen bond (OHB) all played a crucial role in sorption of PCs on three O-rich nanomaterials, they showed significantly different effects on the desorption behaviors of PCs from three sorbents. Compared with OHB (hysteresis index ≤0.0766), the stronger CAHB (hysteresis index ≥0.1981) between PCs and O-rich nanoparticles having comparable pK with PCs, caused obvious desorption hysteresis of PCs, resulting in their better immobilization on O-rich nanomaterials. The FTIR characterization found that both solvent-assisted and solvent-uninvolved CAHB formation resulted in a new characteristic peak appeared in the high frequency (3660 cm for Nano-SiO, 3730 cm for Nano-AlO, and 3780 cm for O-CNTs). Also, density functional theory (DFT) calculation verified that the smaller |ΔpK| between PCs and O-rich sorbents, the shorter bond length, and the larger bond angle resulted in the stronger hydrogen bond formed, thereby leading to the greater immobilization of PCs. These results provide in-depth understanding of the environmental behavior and risk of PCs, and light new idea for designed materials to control PCs pollution in the environment.
各种氢键，特别是电荷辅助氢键（CAHB），被认为是影响药物污染物（PCs）环境行为和风险的重要机制之一。在此，研究了三种富氧（O-rich）纳米粒子（纳米二氧化硅：Nano-SiO、纳米氧化铝：Nano-AlO 和氧化碳纳米管：O-CNTs）上三种 PCs（氯菲酸（CA）、对乙酰氨基酚（ACT）和磺胺甲恶唑（SMZ））的吸附/解吸，以探讨不同氢键对 PCs 环境行为的影响。结果表明，尽管溶剂辅助 CAHB、溶剂不涉及 CAHB 和普通氢键（OHB）都在 PCs 吸附到三种富氧纳米材料中起着关键作用，但它们对 PCs 从三种吸附剂中解吸行为的影响有显著差异。与 OHB（滞后指数≤0.0766）相比，具有与 PCs 可比 pK 的富氧纳米材料之间更强的 CAHB（滞后指数≥0.1981）导致了 PCs 的明显解吸滞后，从而使它们更好地固定在富氧纳米材料上。FTIR 特征发现，溶剂辅助和溶剂不涉及 CAHB 的形成都导致了一个新的特征峰出现在高频（Nano-SiO 为 3660cm，Nano-AlO 为 3730cm，O-CNTs 为 3780cm）。此外，密度泛函理论（DFT）计算验证了 PCs 和富氧吸附剂之间较小的|ΔpK|、较短的键长和较大的键角导致形成更强的氢键，从而导致 PCs 的固定化程度更大。这些结果深入了解了 PCs 的环境行为和风险，并为设计材料控制环境中 PCs 污染提供了新的思路。
