Research Initiation: Modeling and Estimation of ContaminantSoil/Air Fluxes

本项目的目的是为估算地下污染物挥发产生的土壤/空气界面的气体排放通量提供可靠的理论基础，地下污染物包括危险废物泄漏或失控处理、储存和处置地点释放的污染物。对这一主题的研究涉及建立一个预测污染物土壤/空气通量的物理数学模型的理论发展，应用地统计学和其他最优估计器来校准模型参数和在现场尺度上量化模型的不确定性，以及使用现场数据对模型进行验证。该项目强调考虑非饱和区挥发性有机化合物的气相传输和吸附过程，并将明确表示污染物和介质性质、土壤温度变化的时间和空间异质性，并在典型田间条件的模拟中确定。克立格法和贝叶斯估计将用于校准空间和时间相关的模型参数。数据收集工作将补充可用于模型验证的有限现场数据。掩埋地点排放到空气中的有害物质可能会对环境和健康构成重大风险，然而，目前评估和预测这些排放的能力极其有限。这一项目的结果可能为危险废物土壤容纳系统的工程设计提供一个比现在更好的基础。

The objective of this project is to provide a sound theoretical basis for estimating gaseous emission fluxes at soil/air interfaces which arise from volatilization of subsurface contaminants, including those released at leaking or uncontrolled treatment, storage and disposal sites for hazardous waste. Research on this topic involves the theoretical development of a physically based mathematical model for predicting soil/air fluxes of contaminants, application of geostatistical and other optimal estimators for calibrating model parameters and quantifying model uncertainty at the field scale, and validation of the model using field data. The project emphasizes consideration of the gas phase transport and sorption processes in the unsaturated zone for volatile organic compounds and will explicitly represent temporal and spatial heterogeneities in contaminant and media properties, soil temperature changes, and determined in simulations of representative field conditions. Kriging and Bayesian estimation will be used to calibrate spatially and temporally correlated model parameters. A data collection effort will supplement the limited field data available for model validation. Emissions to the air of hazardous substances released at sites where they are buried may pose significant environmental and health risks, however, the current capability to assess and predict these emissions is extremely limited. Results of this project are likely to provide a better basis then is possible now for engineering design of soil-containment systems for hazardous wastes.