Key Laboratory of Surficial Geochemisty, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
Key Laboratory of Surficial Geochemisty, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
J Hazard Mater. 2018 Apr 15;348:92-99. doi: 10.1016/j.jhazmat.2018.01.032. Epub 2018 Jan 20.
In this work, effects of graphene oxide (GO) on the co-transport of the two typical Fluoroquinolones (FQs) - levofloxacin (LEV) and ciprofloxacin (CIP) in saturated and unsaturated quartz sand media were studied. The adsorption isotherms showed that GO had much larger sorption capacities to LEV and CIP than sand with the largest Langmuir adsorption capacity of 409 mg g (CIP-GO); while the sorption affinity of the two FQs onto the two adsorbents might follow the order of CIP-sand > LEV-sand > LEV-GO > CIP-GO. GO promoted the mobility of the two FQs in both saturated and unsaturated porous media due to its strong mobility and sorption capacity. The GO-bound LEV/CIP was responsible for the LEV/CIP transport in the porous media, and transport of GO-bound FQs increased with the increasing of initial GO concentration. Under unsaturated conditions, moisture showed little effect on the transport of GO-bound CIP; however, the mobility of GO-bound LEV reduced with the decreasing of moisture content, suggesting the transport of adsorbed LEV from GO to air-water interface. GO sorption reduced the antibacterial ability of the two FQs, but they were still effective in inhibiting E. coli growth.
本工作研究了氧化石墨烯（GO）对两种典型氟喹诺酮类抗生素（FQs）-左氧氟沙星（LEV）和环丙沙星（CIP）在饱和和非饱和石英砂介质中共运移的影响。吸附等温线表明，GO 对 LEV 和 CIP 的吸附容量远大于砂，最大 Langmuir 吸附容量分别为 409mg/g（CIP-GO）；而两种 FQs 对两种吸附剂的吸附亲和力可能遵循 CIP-砂>LEV-砂>LEV-GO>CIP-GO 的顺序。由于 GO 具有很强的迁移性和吸附能力，GO 促进了两种 FQs 在饱和和非饱和多孔介质中的迁移。GO 结合的 LEV/CIP 是多孔介质中 LEV/CIP 迁移的原因，GO 结合的 FQs 迁移量随初始 GO 浓度的增加而增加。在非饱和条件下，水分对 GO 结合的 CIP 迁移影响不大；然而，GO 结合的 LEV 的迁移性随含水量的降低而降低，表明吸附的 LEV 从 GO 向气-水界面的迁移。GO 吸附降低了两种 FQs 的抗菌能力，但它们仍然有效抑制大肠杆菌的生长。
