| 有机修饰土对苯酚的吸附动力学 |
| 摘要点击 1932 全文点击 822 投稿时间：2008-01-18 修订日期：2008-04-17 |
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| 中文关键词 动力学 吸附 有机修饰 土 苯酚 指数Ⅱ模型 机制 |
| 英文关键词 kinetics adsorption organic modification Lou soil phenol exponential Ⅱ model mechanism |
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| 中文摘要 |
| 以十六烷基三甲基溴化铵单一修饰（CB）和十六烷基三甲基溴化铵+十二烷基磺酸钠混合修饰（CS）土耕层和黏化层土样，采用批处理法通过不同的速度参数研究了修饰土样对苯酚的吸附动力学特征，并对其机制进行了探讨.结果表明，在2个温度下，土两层次修饰土样吸附苯酚的总吸附速度Vt和快速吸附反应速度Vf在低添加浓度下分别为2.64～3.31 μg·(g·h)-1和39.19～61.23 μg·(g·h)-1，在较高添加浓度下分别为13.09～16.30 μg·(g·h)-1和247.87～325.64 μg·(g·h)-1，耕层土样Vt、Vf的大小顺序均为100 CB>120 CS>50 CB>CK，而黏化层土样均为100 CB>50 CB>120 CS>CK.结果证实土两层次土样的有机修饰能够显著加快对苯酚的吸附速度.苯酚的吸附反应分为快速反应和慢速反应2个阶段，总吸附反应以快速吸附反应为主，与快速反应有关的不同速度参数之间具有良好的相关性，而慢速吸附反应则影响不大.修饰土样快速反应和慢速反应的转折时间均小于2 h，且与吸附速度呈现相反的大小顺序.黏化层修饰土样对苯酚的吸附速度高于耕层修饰土样.吸附温度的升高、苯酚添加浓度的提高均可以加快修饰土样对苯酚的吸附反应速度.指数Ⅱ型动力学模型是描述修饰土样吸附苯酚的最佳模型.拟合参数A值与快速吸附反应相关的各项速度参数具有良好的相关性，而模型参数-B与转折时间具有良好的相关性，-B可以作为描述吸附反应速度的特征参数.修饰土样对苯酚的吸附机制以有机相对苯酚的疏水吸附为主. |
| 英文摘要 |
| Using batch experiment, the adsorption kinetics of phenol on both tillage layer (TL) and clay layer (CL) of Lou soil modified with cetyltrimethylammonium bromide (CTMAB, CB) at various ratio (100 CB and 50 CB)and cetyltrimethylammonium bromide+sodium dodecylsulphonate (CTMAB+SDS, CS) mixture were carried out, and its mechanism was discussed also. The results showed that two adsorption velocity parameters of phenol, total-adsorption-velocity (Vt) and fast-adsorption-velocity (Vf), on both layers of modified soil are 2.64-3.31 μg·(g·h)-1, 39.19-61.23 μg·(g·h)-1 at low added phenol concentration respectively and 13.09-16.30 μg·(g·h)-1, 247.87-325.64 μg·(g·h)-1at high added phenol concentration respectively at two experimental temperature, moreover, the two velocity parameters have a same sequence in different modification treatments, i.e. ordered by 100 CB>120 CS>50 CB>CK in TL treatment and by 100 CB>50 CB>120 CS>CK in CL treatment. These outcomes indicated that the modification on the both layers of Lou soil increases significantly the adsorption velocity of phenol. The adsorption of phenol is divided into two stages, fast adsorption and slow adsorption, in which the adsorption of phenol is primarily decided by the fast adsorption while it is affected little by slow adsorption. Therefore, the velocity parameters that relate with the fast adsorption have better correlation between them. The time of conversion (tc) between fast adsorption and slow adsorption in modified soil is less than 2 h, and shows a reverse sequence in different modification treatments compared to the adsorption velocity parameters. The adsorption velocity of modified CL to phenol is higher than that of modified TL. The adsorption velocity of organic modified soil to phenol can be increased by an increase of both temperature and added concentration of phenol. The exponential Ⅱ kinetic model is the best model to describe the adsorption kinetic curves of phenol on modified soil, furthermore, the fitted parameter A has better correlation with the velocity parameters related to the fast adsorption while the fitted parameter －B, which can become a characteristic parameter to describe the adsorption velocity, has better correlation with the time of conversion tc. The adsorption of phenol on the modified soil is primarily decided by the hydrophobic adsorption of organic phase on the surface of modified soil. |
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