【作者】 张志鹏；

【导师】 龚正君；

【作者基本信息】 西南交通大学 ， 环境工程， 2012， 硕士

【摘要】 本论文选用花生壳、稻草秸秆为原材料,采用物理、化学方法制备了4种吸附剂,用吸附法处理溶液中苯酚。主要研究内容如下：考察了原始材料、炭化材料、改性材料对苯酚的吸附性能。通过静态实验,研究了不同pH、时间、离子强度、投加量、温度及初始浓度条件对苯酚吸附效果的影响。通过吸附时间及不同初始浓度的吸附实验数据,拟合吸附动力学及吸附热力学曲线。实验结果表明：1、当溶液pH=7,花生壳与苯酚接触时间为360min可达到吸附平衡；稻草秸秆吸附苯酚的溶液pH=4,接触时间为360min时达到吸附平衡。随着溶液中离子强度的增大,吸附剂对苯酚的去除率明显下降。根据Langmuir模型计算,稻草秸秆对苯酚的吸附容量为6.7mg/g。花生壳吸附苯酚符合Freundlich模型。两种吸附剂对苯酚的吸附过程符合一级动力学模型。通过热力学计算表明稻草秸秆吸附苯酚是自发、吸热过程。2、在不同的炭化温度条件下制备吸附剂,通过吸附试验确定适宜的炭化温度。炭化花生壳和炭化稻草秸秆对苯酚的吸附试验结果表明,当溶液pH=7,炭化花生壳与苯酚接触时间为240min可达到吸附平衡；炭化稻草秸秆吸附苯酚的溶液pH=8,与苯酚最佳接触时间为240min可达到吸附平衡。随着溶液中离子强度的增大,吸附剂对苯酚的去除率明显下降。根据Langmuir模型计算,在不同温度下炭化花生壳对苯酚的最大吸附容量为54.07-57.04mg/g,炭化稻草秸秆对苯酚的最大吸附容量为28.43-33.35mg/g。两种吸附剂对苯酚的吸附过程符合Langmuir和Freundlich模型,符合二级动力学曲线。通过热力学计算表明炭化花生壳和炭化稻草秸秆吸附苯酚是自发、放热过程。3、以N,N-二甲基甲酰胺为反应介质,利用环氧氯丙烷、二甲胺和吡啶引入胺基基团制备改性花生壳和改性稻草秸秆。试验结果表明,当溶液pH=10,改性花生壳与苯酚接触时间为120min可达到吸附平衡；改性稻草秸秆吸附苯酚的溶液pH=10,与苯酚最佳接触时间为240min可达到吸附平衡。随着溶液中离子强度的增大,吸附剂对苯酚的去除率明显下降。根据Langmuir模型计算,改性花生壳对苯酚的最大吸附容量为84.49-108.76mg/g,改性稻草秸秆对苯酚的最大吸附容量为51.10-91.50mg/g。吸附过程符合Langmuir和Freundlich模型,二级动力学方程。通过热力学计算表明改性花生壳和改性稻草秸秆吸附苯酚是自发、吸热过程。更多还原

【Abstract】 The peanut shells and rice straws were preferred for raw material, and each of which was treated to four adsorbent by physical or chemical method. The adsorption method was used as the way to deal with the phenol in solution. The main results as follows:the adsorption capacity of adsorbents (raw material, carbonated material, modified material) adsorb phenol were explored. The influence of pH, adsorption time, ionic strength, dosage, temperature and primary concentration to adsorption effect were investigated in static tests. The adsorption theory could be known by the fitting results of adsorption kinetics and thermodynamics, which were based on the data of adsorbing time test and different initial concentrations test. The experimental results show that:1、 When the pH of the solution was7, the process of peanut shells adsorbing phenol reached balance after360min. For rice straws, the pH was4and the time was360min. With raising the ionic strength, the removal efficiency was obviously decline. According to Langmuir model, the maximum amounts adsorption of rich straws was6.7mg/g, and the adsorption of peanut shells absorbing phenol meet Freundlich model. By substituting experimental data into kinetics models, the first-order kinetics model could better describe the kinetics of adsorbent adsorbing phenol.The thermodynamic calculations results indicated that the process of rice Straws adsorbing phenol was spontaneous and endothermic.2、 The suitable carbonization temperature was defined by using adsorbent of different temperature for test. The results show that:when the pH of the solution was7, the process of carbonated peanut shells adsorbing phenol could reach balance after240min. For carbonated rice straws, the pH was8and the time was240min. With raising the ionic strength, the removal efficiency was obviously decline. Both of the two adsorbing processes meet the isothermal adsorption characteristic of the two kind of adsorbent adsorbing phenol conformed to both Langmuir equation and Freundlich equation, the maximum amounts adsorption of carbonated peanut shells was54.07-57.04mg/g. The maximum amounts adsorption of carbonated rice straws was28.43~33.35mg/g. Both of the two adsorbing processes meet the second-order kinetics model, The thermodynamic calculations results indicated that the process of the two kinds of adsorbent adsorbing phenol were spontaneous and exothermic. 3、 The modified peanut shells and modified rice straws were prepared by using N,N-dimethylformamide as reaction medium and using chloroepoxy propane、dim ethylamine and pyridine as modifying agent. The results show that: when the pH of the solution was10, the process of modified peanut shells adsorbing phenol could reach balance after120min. For modified rice straws, the pH was10and the time was240min. With raising the ionic strength, the removal efficiency was obviously decline. Both of the two adsorbing processes meet the isothermal adsorption characteristic of the two kinds of adsorbent adsorbing phenol conformed to both Langmuir equation and Freundlich equation, the maximum amounts adsorption of modified peanut shells was84.49~108.76mg/g. the maximum amounts adsorption of modified rice straws was51.10~91.50mg/g. Both of the two adsorbing processes meet the second-order kinetics model. The thermodynamic calculations results indicated that the processes of the two kind of adsorbent adsorbing phenol were spontaneous and endothermic.更多还原