• 关键词：抗生素  迁移  环境风险  离子强度  柱实验  介质粒径

• 基金项目：江西省青年科学基金（No.20181BAB213015）；国家自然科学基金项目（No.51861145308）；江西省水利厅科技项目（No.201820YBKT23）

• 孙凯璇
• 东华理工大学水资源与环境学院, 南昌 330013

• 向令
• 东华理工大学水资源与环境学院, 南昌 330013

• 孙占学
• 1. 东华理工大学水资源与环境学院, 南昌 330013;2. 东华理工大学核资源与环境国家重点实验室, 南昌 330013

• 章艳红
• 东华理工大学水资源与环境学院, 南昌 330013

• 时延锋
• 山东建筑大学市政与环境工程学院, 济南 250101

• 摘要：为系统探究抗生素在饱和多孔介质中的迁移行为，选取两类典型抗生素—磺胺类（Sulfonamides， SAs）和氟喹诺酮类抗生素（Fluoroquinolones， FQs），通过室内砂柱迁移实验，重点对比研究了水化学条件及介质粒径对两类抗生素迁移的影响.结果表明，不同种类抗生素在饱和石英砂多孔介质中的迁移特性不同.在实验pH（5.6~9.5）条件下，低解离常数使得SAs多以带负电形态出现，因静电斥力导致SAs在石英砂介质中具有强迁移能力，流出液中SAs回收率>97%；pH、离子强度（NaCl、CaCl₂）及介质粒径对抗生素的迁移无显著影响.FQs多呈阳离子形态及两性形态，受静电引力控制，FQs迁移能力相对较弱，但移动性随溶液pH升高而增大，NaCl和介质粒径对FQs迁移影响不显著，竞争吸附导致高浓度CaCl₂促进FQs迁移能力.本研究结果阐明了SAs和FQs在多孔介质中不同水化学条件（pH、NaCl及CaCl₂离子强度）下及不同介质粒径中的迁移过程，可为抗生素环境风险的预测和评估及污染修复提供指导.

• Abstract：To systematically investigate the transport characteristics of antibiotics in saturated porous media, transport behaviors of sulfonamides (SAs) and fluoroquinolones (FQs) in a quartz-loaded column were investigated under different hydrochemical conditions and grain sizes. Results showed that transport behaviors of the investigated antibiotics varied in saturated quartz sand porous media. Specifically, SAs, which were negatively charged and had low dissociation constants under the experimented pH, showed high mobility in quartz sand porous media due to electrostatic repulsion. The SAs effluent recovery rate therefore were all >97%. However, pH, ionic strength (NaCl and CaCl₂), and grain size showed no significant effect on SAs transport. Fluoroquinolones exhibited low lower mobility as compare to SAs, which was due to that fluoroquinolones occurred as cationic and neutral compounds rendering electrostatic reactions. While, with an increase of solution pH, the mobility of FQs was enhanced. Similarly, NaCl, as well as grain size, had no significant effect on FQs transport. Competitive adsorption leading to high concentration of CaCl₂ would be a main mechanism for promoting FQs transport. The findings reported in this study unraveled the transport behaviors of SAs and FQs in porous media under various conditions (grain size, pH, ionic strength), which would be helpful in predicting and assessing the environmental risks of antibiotics and remediating antibiotic-contaminated natural systems.

• Key words：antibiotics  transport  environmental risk  ionic strength  column experiment  grain size

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