Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
Environ Sci Pollut Res Int. 2017 Oct;24(30):23834-23842. doi: 10.1007/s11356-017-0038-7. Epub 2017 Sep 3.
Given their voluminous application, significant amounts of fluoroquinolones are discharged into the environment through wastewater effluent. Adsorption has been shown to be a critical process controlling the environmental behaviors of fluoroquinolones. Competition between ofloxacin (OFL) and naphthalene (NAP)/bisphenol A (BPA) and their adsorption on activated carbon (AC), graphite (GP), and humic acid (HA) were investigated. The suppressed adsorption of OFL was observed on AC and GP, but not on HA, by NAP or BPA. Moreover, for AC, the competition by NAP was slightly stronger than that by BPA. However, for GP, the competition with BPA was higher than that with NAP. These observations indicate that competitive adsorption of OFL with respect to NAP/BPA depends on the degree of overlap of adsorption sites, as interpreted by the following: (i) AC can provide overlapping adsorption sites for OFL, BPA, and NAP, which include non-specific adsorption sites, such as hydrophobic sites, π-π interactions, and micropore filling; (ii) π-π interactions and hydrogen bonding might be responsible for the strong competitive adsorption between BPA and OFL on GP; and (iii) OFL adsorbs on HA through specific adsorption force-electrostatic attraction, with which NAP and BPA cannot compete.
鉴于其大量的应用，相当数量的氟喹诺酮类药物通过废水排放到环境中。吸附已被证明是控制氟喹诺酮类药物环境行为的关键过程。研究了氧氟沙星（OFL）与萘（NAP）/双酚 A（BPA）之间的竞争及其在活性炭（AC）、石墨（GP）和腐殖酸（HA）上的吸附。观察到 NAP 或 BPA 会抑制 OFL 在 AC 和 GP 上的吸附，但不会在 HA 上抑制。此外，对于 AC，NAP 的竞争略强于 BPA。然而，对于 GP，与 BPA 的竞争高于与 NAP 的竞争。这些观察表明，OFL 与 NAP/BPA 的竞争吸附取决于吸附位点的重叠程度，可解释为：（i）AC 可为 OFL、BPA 和 NAP 提供重叠的吸附位点，包括非特异性吸附位点，如疏水性位点、π-π 相互作用和微孔填充；（ii）π-π 相互作用和氢键可能是 BPA 和 OFL 在 GP 上强烈竞争吸附的原因；（iii）OFL 通过静电引力与腐殖酸发生特异性吸附，NAP 和 BPA 无法与之竞争。
