【摘要】 基于多孔介质流体动力学理论,建立了填埋场中VOC传输过程的环境诊断模型,给出了模型的有限差分格式。采用所建立的数值模型对垃圾填埋场范围内(含4口注气井和1口抽气井)VOC释放的过程进行了环境诊断分析,研究了苯类有机物在填埋场中的浓度分布趋势。环境诊断结果表明:随着时间的增长,VOC的浓度逐渐降低,气体浓度分布面积也逐步缩小。尤其在抽气前期,气体浓度大幅度降低,主要是由于抽气开始压力迅速释放而导致的。但随着时间的延长,其内部压力梯度逐步减小,气体抽出量降低,直至填埋场内气体被排出。这为填埋场抽排气系统的设计和管理提供技术指导。更多还原

【Abstract】 A environmental diagnosis model of volatile organic compounds transport has been established based on the theory of seepage mechanics.Solutions to the coupled equations are accomplished by finite difference method.The numerical model is used to simulate the release process of volatile organic compounds in landfill site(including 4 injection wells and 1 extraction well).The concentration distribution in landfill site is given.Results show that concentration distribution of volatile organic compounds has a trend of decrease with time,and the concentration distribution area decrease.It has a large impact on vapor concentrations at the early stage.The mainly reason is that gas pressure release in landfill, but with time increasing,gas pressure gradient and gas output decrease.The technology supporting is provided for designing soil vapor extraction system engineering and field management.更多还原