• 关键词：环丙沙星  石英砂  pH  离子强度  粒径  参数

• 基金项目：国家自然科学基金项目(No.40771095,41171183);山东省自然科学基金青年基金项目(No.ZR2014DQ021)

• 徐秀姣
• 青岛大学环境科学与工程学院, 青岛 266071

• 林青
• 青岛大学环境科学与工程学院, 青岛 266071

• 徐绍辉
• 青岛大学环境科学与工程学院, 青岛 266071

• 摘要：通过批量静态吸附实验,分析不同pH、离子强度、粒径下环丙沙星在石英砂上的吸附特征,实验数据用Langmuir与Freundlich两个方程进行拟合;并做室内石英砂柱迁移实验,探讨了不同因素对环丙沙星在石英砂中运移的影响;获得了示踪剂Br^-和环丙沙星的穿透曲线,并用HYDRUS-1D软件对实验结果进行了模拟.研究表明:环丙沙星在石英砂上的吸附能力与pH、离子强度及粒径大小成负相关.随着pH、离子强度及粒径增大,出流时间变短,达到C/C₀峰值的时间也变短,从出流到相对浓度衰减为零整个过程的时间跨度越小.在低离子强度下,环丙沙星在不同粒径的石英砂中的运移,一般粒径越大,出流越早,峰值越高.描述溶质运移的非平衡一点模型(OSM)能够较好地模拟环丙沙星在石英砂中的运移过程,用数值反演得到的参数所求出的阻滞因子R_d值比根据Freundlich方程拟合得到的参数求出的R_d值要小,但它们均符合静态吸附实验和动态迁移实验的特点.pH越大,模拟得到的分配系数K_d值越小,分形系数β值、一阶速率系数ω值均很小且无明显变化规律;离子强度越大,模拟得到的分配系数K_d值、分形系数β值及一阶速率系数ω值就越小.

• Abstract：Batch adsorption equilibrium experiments were conducted to study the effect of pH, ionic strength and particle size on ciprofloxacin adsorption in quartz sand. The results of the adsorption experiment were simulated by using Langmuir and Freundlich isotherm. The displacement experiment under different conditions was also conducted in order to analyze the effect of different factors on ciprofloxacin transport in quartz sand. The breakthrough curves (BTCs) of the tracer bromide (Br^-) and ciprofloxacin were obtained. Then the experimental data were simulated with software HYDRUS-1D. The results show that the adsorption capability of ciprofloxacin in quartz sand is negatively correlated with pH, ionic strength and particle size. With the increase of pH, ionic strength and particle size, the outflow time and the time to reach the peak (C/C₀) become shorter. And also the time span throughout the transport process becomes smaller. Under the low ionic strength condition, the effect of particle size on ciprofloxacin transport is that the larger the particle size is, the sooner the outflow time is, and the higher the peak value is. The non-equilibrium single-point adsorption model (OSM) in HYDRUS-1D can better describe the migration behavior of ciprofloxacin in quartz sand. And the retardation factor R_d obtained by inversion is smaller than the R_d fitted by Freundlich equation. But it is consistent with the characteristics of static and dynamic experiments. The higher the pH is, the smaller the partition coefficient K_d is obtained. Both the fractal coefficient β and the first order rate coefficient ω are small with no apparent changing rule. The higher the ionic strength is, the smaller the simulated parameters of K_d, β and ω are.

• Key words：ciprofloxacin  quartz sand  pH ionic strength  particle size  parameter

• 
  摘要点击次数： 1202 全文下载次数： 3175