Henan Joint International Research Laboratory of Environmental Pollution Control Materials, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, China.
Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300350, China; Department of Hydrology, University of Bayreuth, Bayreuth, D-95440, Germany.
Environ Pollut. 2021 Jan 1;268(Pt A):115730. doi: 10.1016/j.envpol.2020.115730. Epub 2020 Sep 26.
In this study, batch and column tests were performed to investigate the co-transport of graphene oxide (GO) nanoparticles and tetracycline in saturated porous media under various solution chemistry conditions. Research indicated that GO and tetracycline had mutual promotion effect on their transport in the porous media under all the tested conditions, which was ascribed to the high adsorption capacity of tetracycline onto GO and the increased electrostatic repulsion as well as their competition for deposition sites on sand surfaces. Interestingly, the mutually promoting function of GO and tetracycline under acidic conditions was greater than that under alkaline conditions, the dominant mechanism was that the increased solution pH decreased the sorption of tetracycline onto GO and weakened the deposition site competition. Furthermore, the mutually promoting effect of GO and tetracycline was Na or Ca concentration-dependent. Specially, increased Ca concentration weakened the promoting effect of GO on tetracycline transport but magnified the promoting effect of tetracycline on GO transport. This is because higher Ca concentration could cause a decrease in the adsorption of tetracycline on GO and facilitate more tetracycline molecules to occupy the deposition sites on sand surfaces. Additionally, sodium dodecyl sulfate had enhancement effect on co-transport of GO and tetracycline. Findings from this study clearly indicated that antibiotics and carbon based nanomaterials may transport together under various solution chemistry conditions, and consequently affect their fates in aquatic environments.
在这项研究中，通过批次和柱试验研究了在不同溶液化学条件下，氧化石墨烯（GO）纳米颗粒和四环素在饱和多孔介质中的共迁移。研究表明，在所有测试条件下，GO 和四环素在多孔介质中的迁移都具有相互促进作用，这归因于四环素对 GO 的高吸附能力以及增加的静电排斥和它们对砂表面沉积位点的竞争。有趣的是，GO 和四环素在酸性条件下的相互促进作用大于碱性条件下的相互促进作用，主要机制是增加溶液 pH 值降低了四环素对 GO 的吸附作用，并削弱了沉积位点的竞争。此外，GO 和四环素的相互促进作用与 Na 或 Ca 浓度有关。具体而言，增加 Ca 浓度会减弱 GO 对四环素迁移的促进作用，但会放大四环素对 GO 迁移的促进作用。这是因为较高的 Ca 浓度会导致四环素在 GO 上的吸附减少，并促进更多的四环素分子占据砂表面的沉积位点。此外，十二烷基硫酸钠对 GO 和四环素的共迁移具有增强作用。本研究的结果清楚地表明，抗生素和碳基纳米材料可能在各种溶液化学条件下一起迁移，并因此影响它们在水生环境中的命运。
