改良耕层土壤中苯胺的吸附动力学

研究有机改良土壤对污染物的动力学吸附特征,有助于深入了解其对污染物的吸附机制。以十六烷基三甲基溴化铵单一改良（CB）和十六烷基三甲基溴化铵＋十二烷基磺酸钠混合改良（CS）塿土耕层土样,采用批处理法通过不同的速度参数研究了改良土壤对苯胺的吸附动力学特征,并与苯酚对比探讨改良土样对有机污染物吸附的动力学机制。结果表明,塿土耕层土样的有机改良能够显著加快对苯胺的吸附速度,苯胺的吸附反应呈现快速反应和慢速反应两个阶段,且以快速吸附反应为主。总体上耕层土样Vt、V0.5、Vf的大小顺序均为100CB＆gt;120CS＆gt;（≈）50CB＆gt;CK。随温度升高和苯胺添加浓度增大,苯胺吸附速度增大,苯胺、苯酚的吸附动力学特征在改良土样上具有良好的相似性,从而证实有机污染物以分子状态存在导致的单一疏水吸附是改良土样吸附的决定机制。

Adsorption Kinetics of Aniline in Soil of Modified Tillage-Layer

Using batch experiment, the adsorption kinetics of aniline in tillage layer（TL） of Lou soil modified with eetyhrimethylammonium bromide （CTMAB, CB ） at various ratio （100CB and 50CB ） and eetyhrimethylammonium bromide ＋ sodium dodecylsulphonate （CTMAB＋ SDS, CS） mixture were carried out, and comparing to the phenol, the adsorption mechanism of modified TL of Lou soil to organic pollutants was discussed also. The results showed that the modification on the TL of Lou soil increased significantly the adsorption velocity of aniline at two experimental temperature, three adsorption velocity parameters of aniline, total-adsorption-velocity （V1）, fast-adsorption-velocity（V1） and initial-adsorption-velocity（V0.5）, on modified soil were 1.62-6.60, 1.62-10.88 and 2.42-12.15 times higher than that on unmodified soil respectively. The adsorption of aniline was divided into two stages, fast adsorption and slow adsorption, in which the adsorption of aniline was primarily decided by the fast adsorption. These velocity parameters of aniline, V1, V1 and V0.5, had a same sequence in different modification treatments, i.e. ordered by 100CB〉120CS〉（ ≈ ）50CB〉GCK. The adsorption velocity of organic modified soil to aniline could be increased by an increase of both temperature and added concentration of aniline. The adsorption kinetics characteristics of aniline were similar to that of phenol on the modified soil, but had different temperature effect on unmodified soil, these outcomes demonstrate that the hydrophobic adsorp- tion resulted from molecular state of organic pollutants is the sole adsorption mechanism in organic modified soil.