泥炭对甲苯的吸附-解吸行为研究

用热处理方法对泥炭进行活化改性,探讨了对甲苯的吸附性能及影响因素,并研究了甲苯在泥炭上的吸附/解吸行为。结果表明,粒径在0.6～1 mm之间的泥炭在160℃热处理5 h,在pH为7的条件下对甲苯有良好的吸附效果,对甲苯的吸附量为0.32 mg/g。泥炭对甲苯的吸附在20 min内基本达到平衡,可用二级吸附速率方程进行拟合。甲苯在泥炭上的吸附和解吸均呈现明显的非线性,用Langmuir模型能较好地描述,泥炭对甲苯的饱和吸附量为0.939 mg/g。甲苯在泥炭上的平均解吸率为6.393%,并且出现了滞后现象,表明苯系物与泥炭有较强的结合能力。研究结果为应用泥炭作为PRB装填介质进行原位修复甲苯污染的地下水提供了理论依据。

Study on adsorption and desorption behavior of toluene by peat

The peat was modified by heat treatment.The properties and main influential factors of modified peat for adsorption of toluene in the solutions were experimentally investigated.The results showed that the adsorption ability for toluene was greatly improved under the conditions that heat treatment temperature was 160℃,time was 5 h,size was 0.6~1 mm,pH was 7.The adsorption rate of toluene was 0.32 mg/g.The adsorption of toluene by peat could reach balance at 20 min.It was fit for the secondary absorption rate equation.All the sorption and desorption isotherms of toluene on the peat were nonlinear,which can be well fitted by Langmuir model.The saturate adsorption capacity of toluene by peat was 0.939 mg/g.The average desorption rate of toluene on peat was 6.393%.Desorption hysteresis of toluene on peat was evident which showed that peat had a strong binding capacity with toluene.It provides a theoretical foundation for using peat as new PRB filling material to in situ remediate BTEX contaminated groundwater using absorption-degeading method.