生物渗透反应格栅修复甲基叔丁基醚污染地下水的模拟

渗透反应格栅技术(PRB)修复污染地下水的现场模拟是实际工程设计、过程预测及修复效果评价的有效手段.以甲基叔丁基醚(MTBE)为研究对象,在多孔介质流体动力学、传质学、生物降解动力学等基础上,建立了生物渗透反应格栅修复MTBE污染地下水的数学模型.由双柱法的实验结果可知,模型模拟结果与实验数据的平均相对误差为5.74%,说明文中所建模型能够很好地描述MTBE在反应格栅内的降解去除过程;由污染物在格栅及其附近区域的浓度分布可知,由于部分流体从格栅侧面进入,污染物在此流径上得不到充分降解,表现为生物渗透反应格栅系统处理后的地下水区域边缘处的MTBE浓度高于其中心区域浓度,该结果可用于指导现场PRB系统及其附属设施的设计和安装.

Simulation of Remediation of Methyl Tertiary Butyl Ether Contaminated Groundwater Using Biological Permeable Reactive Barrier

Applying the permeable reactive barrier (PRB) to remedy the contaminated groundwater is a fast emerging technology for in situ remediation of contaminated groundwater, and it has many advantages over the traditional methods of ex situ treatment. The mathematical simulation of the remediation by PRB is a useful tool for optimizing the barrier design, predicting the remove process and evaluating the efficiency of remediation. In this paper, the mathematical models of special PRB system were presented, which can be used to simulate the removal process of methyl tertiary butyl ether (MTBE) from groundwater by using a biological permeable reactive barrier. The average error of 5.74% between the simulated results and the experimental data obtained from experimental test column shows that the models proposed are available. Moreover, as seen from the distribution of MTBE concentration in the computation domain, parts of contaminated groundwater flow into the barrier through its two side surfaces and form shortcut flow paths through the barrier, and the MTBE in those shortcut flows can not be fully degraded. As a result, after treating, the MTBE concentration of the treated groundwater flowing near the two side region of the biological permeable reactive barrier is higher than that of the flow flowing through the center region of the PRB. Knowing above phenomena will be helpful for PRB system design to remedy the MTBE contamination of the groundwater.