摘要
采用通量箱（30．0cm×17．5cm×29．0cm）研究砂土与黑土中苯挥发过程中的影响因素和通量变化特征．通过模拟不同空气流速、不同温度，并设定土壤类型、土壤含水量、初始浓度等条件，实时监测通量箱中各层土壤气相中和土壤上方空气中苯的浓度，来分析不同条件下苯的挥发特征．结果表明，砂土和黑土中苯的挥发通量分别随着土壤含水量的增加而降低，土壤充气空隙率相近情况下，苯在砂土中的挥发通量明显高于黑土．空气流速在300～900mL·min^-1范围内，砂土中苯挥发通量随空气流速升高而加大；在20～40℃范围内对黑土的试验结果表明，苯挥发强度受温度影响显著．苯挥发通量与土壤中苯浓度呈线性相关，其可根据土壤中苯初始浓度和水溶出浓度进行预测．
The influencing factors of benzene diffusion fluxes from sand and black soil to atmosphere were investigated using a flux chamber （30.0 cm ×17.5 cm × 29.0 cm）. In this study, the benzene diffusion fluxes were estimated by measuring the benzene concentrations both in the headspace of the chamber and in the soils of different layers. The results indicated that the soil water content played an important role in benzene diffusion fluxes. The diffusion flux showed positive correlation with the initial benzene concentration and the benzene dissolution concentration for both soil types. The changes of air flow rate from 300 to 900 mL.min^-1 and temperature from 20℃ to 40℃ resulted in increases of the benzene diffusion flux. Our study of benzene diffusion fluxes from contaminated soils will be beneficial for the predicting model, and emergency management and precautions.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2013年第12期4627-4634,共8页
Environmental Science
基金
环境保护公益性行业科研专项(201109017)
关键词
苯
污染土壤
挥发
通量箱
通量特征
benzene
contaminated soil
diffusion flux
flux chamber
flux characteristics
