含有非水相液体(苯)的土壤气相抽提体系传质实验研究  

MASS TRANSFER IN NAPL(BENZENE)-CONTAINING SVE SYSTEM

作　　者：杨乐巍[1] 沈铁孟[1] 肖锋[1] 周清[1] 黄国强[1,2] 李鑫钢[1,2] 

机构地区：[1]天津大学化工学院,天津300072 [2]天津大学精馏技术国家工程研究中心,天津300072

出　　处：《土壤学报》2008年第6期1046-1050,共5页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(批准号:50708064)

摘　　要：选取砂土作为实验室一维土柱通风实验的研究对象,考察了不同含水量(0%、21.9%、36.6%及51.2%)条件下,苯在气-水-油-固4相共存的土壤气相抽提体系(Soil vapor extraction,SVE)体系中的相间传质过程。并用局部相平衡模型及非平衡动力学模型预测结果与实验结果进行了比较。干燥情况下,局部相平衡模型可以描述通风过程,随着含水量的增加实验结果严重偏离平衡模型。含水量为21.9%、36.6%及51.2%时,非平衡动力学模型与实验结果较为符合。结果表明,土壤含水量影响气-液(Non-aqueousphase liquid,NAPL)间的传质,干燥土壤中相平衡模型可以描述SVE修复过程。随含水量的增加修复进程偏离相平衡模型较严重,此时需要用非平衡动力学模型来描述。An in-lab unidimensional soil-column venting experiment was conducted with sandy soil to investigate mass transfer process of non-aqueous phase liquid （benzene） in the soil vapor extraction system composed of gas, water, oil and solid substances at four moisture levels （0% , 21.9% , 36.6% and 51.2% ）. Results of the experiment were compared with those of the prediction using the Local Phase Equilibrium Model （LPEM） and Non-Equilibrium Kinetic Model（NEKM）. When the moisture level was 0% , the LEM model fitted well the ventilation process of the soil column; but with the moisture level rising, its prediction seriously deviated from the experiment results. However, in this case, the prediction of the NEKM model fitted better with the experiment results. The findings show that moisture level of the soil affects Gas-NAPL mass transfer. The LPEM model may be used to describe the process of SVE remediation in dry soil, whereas the NEKM model should be used in soils higher in moisture content.

关 键 词：土壤气相抽提 土柱通风实验 气-液传质 局部相平衡模型 非平衡动力学模型 

分 类 号：S152.6[农业科学—土壤学] TQ028.1[农业科学—农业基础科学]