改性活性炭对水中环丙沙星的吸附性能研究

发布时间：2019-03-03 13:17

【摘要】：近些年来,在各种水环境中均不同程度的检测出抗生素。不同环境介质中环丙沙星的浓度虽然比较低但可能诱导病原菌产生耐药性对生态系统和人类健康产生严重威胁。因此研究含环丙沙星污水的处理具有重要的现实意义。常用的方法有:物理法、化学法、生物处理方法等,其中吸附法因其投资小、工艺简单、操作方便而被广泛使用。本文筛选了对环丙沙星有良好吸附作用的吸附剂并确定了它的最优吸附条件,且对其进行了浸渍改性。考察了吸附时间、初始浓度、温度、pH、水质等因素对改性活性炭吸附水中环丙沙星效果的影响。利用等温线模型和动力学模型对吸附数据进行拟合,并对其的吸附性能和吸附机理进行探究。通过BET,XRD对SDBS改性活性炭进行了表征。主要研究结果如下:(1)不同吸附剂(沸石、活性氧化铝、高岭土、竹炭、活性炭、弗罗里硅土、蒙脱石)对水中的环丙沙星吸附实验。表明活性炭对环丙沙星的吸附效果最好。(2)通过采用酸、碱、盐、表面活性剂等对活性炭进行浸渍法改性。探究了不同的改性剂浓度、浸泡时间和固液比对改性活性炭对环丙沙星吸附容量的影响。确定最佳的改性方法为:用2g/L的SDBS以1:10的固液比浸泡活性炭4h。在环丙沙星溶液初始浓度为5mg/L时,SDBS-AC对环丙沙星的吸附量为27.1mg/g,而相同条件下AC对环丙沙星的吸附量为18.32mg/g,改性后比改性前吸附容量提高了50%。(3)SDBS-AC吸附动力学研究结果表明,在实验最初4h吸附速率较快,然后逐渐减缓,在10h左右达到吸附平衡。通过对改性活性炭的吸附速率曲线进行拟合表明其更符合拟二级动力学方程。(4)SDBS-AC吸附热力学研究结果表明,改性活性炭对环丙沙星的吸附行为可用Langmuir吸附等温线描述。随着温度的升高,吸附容量增大。(5)改性活性炭的比表面积相对未改性活性炭比表面积减小,但是孔径却略微增大。其改性前后的晶体结构未有改变。(6)对改性活性炭过程中所使用的改性剂进行安全性评价,符合国家生活饮用水安全标准。(7)改性活性炭在去离子水中对环丙沙星的吸附效果要好于自来水中的吸附效果。
[Abstract]:In recent years, antibiotics have been detected in various water environments to varying degrees. Although the concentration of ciprofloxacin in different environmental media is relatively low, it may induce drug resistance of pathogenic bacteria, which may pose a serious threat to ecosystem and human health. Therefore, it is of great practical significance to study the treatment of wastewater containing ciprofloxacin. The commonly used methods include physical method, chemical method, biological treatment method and so on. Adsorption method is widely used because of its small investment, simple process and convenient operation. In this paper, the adsorbents with good adsorption capacity for ciprofloxacin were screened and the optimal adsorption conditions were determined, and the adsorbents were modified by impregnation. The effects of adsorption time, initial concentration, temperature and water quality of pH, on ciprofloxacin adsorption by modified activated carbon were investigated. The adsorption data were fitted by isothermal model and kinetic model, and the adsorption performance and adsorption mechanism were investigated. SDBS modified activated carbon was characterized by BET,XRD. The main results are as follows: (1) the adsorption of ciprofloxacin by different adsorbents (zeolite, activated alumina, kaolin, bamboo charcoal, activated carbon, Florisil, montmorillonite) in water. The results showed that the adsorption of ciprofloxacin on activated carbon was the best. (2) the activated carbon was modified by impregnation with acid, alkali, salt and surfactant. The effects of different modifier concentration, immersion time and solid-liquid ratio on the adsorption capacity of ciprofloxacin on modified activated carbon were investigated. The optimum modification method was as follows: the activated carbon was soaked in the SDBS of 2g/L for 4 h at 1:10 solid-liquid ratio. When the initial concentration of ciprofloxacin is 5mg/L, the adsorption amount of ciprofloxacin by SDBS-AC is 27.1 mg / kg, and that of ciprofloxacin by AC is 18.32 mg / kg under the same conditions. The adsorption capacity after modification was 50% higher than that before modification. (3) the adsorption kinetics of SDBS-AC showed that the adsorption rate was faster at the first 4 h, then slowed down gradually, and reached the adsorption equilibrium at about 10 h. The curve of adsorption rate of modified activated carbon was fitted to the pseudo-second order kinetic equation. (4) the results of SDBS-AC adsorption thermodynamics study showed that the adsorption rate curve of modified activated carbon was better than that of modified activated carbon. The adsorption behavior of ciprofloxacin on modified activated carbon can be described by Langmuir isotherm. With the increase of temperature, the adsorption capacity increases. (5) the specific surface area of the modified activated carbon decreases relative to the unmodified activated carbon, but the pore size increases slightly. The crystal structure did not change before and after modification. (6) the safety of modifiers used in the process of modified activated carbon was evaluated. (7) the adsorption effect of modified activated carbon on ciprofloxacin in deionized water is better than that in tap water. (7) the adsorption effect of modified activated carbon on ciprofloxacin in deionized water is better than that in tap water.
【学位授予单位】：安徽农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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