Cunningham Jeffrey A, Reinhard Martin
Department of Civil and Environmental Engineering, Stanford University, CA 94305-4020, USA.
Ground Water. 2002 Nov-Dec;40(6):599-607. doi: 10.1111/j.1745-6584.2002.tb02546.x.
Two of the biggest drawbacks of using permeable reactive barriers (PRBs) to treat contaminated ground water are the high capital cost of installation, particularly when the contaminated ground water is deep below ground surface, and the uncertainty of whether or not PRBs remain effective for the long time scales (e.g., decades) needed for many contaminant plumes. The use of an injection-extraction treatment well pair (IETWP) for capture and treatment of contaminated ground water can circumvent these difficulties, while still providing many of the same advantages offered by PRBs. In this paper, the hydraulics of IETWPs and PRBs are compared, focusing primarily on the width of the captured plume. It is demonstrated that IETWPs act as hydraulic barriers in a manner similar to PRBs, and that IETWPs provide excellent plume capture. A mathematical expression is presented for the plume capture width of an IETWP oriented perpendicular to the ground water flow direction in a homogeneous aquifer. Also discussed are other practical considerations that might determine whether an IETWP is better suited than a PRB for a particular contaminated site; these considerations include operating and maintenance costs, and the conditions under which an IETWP system can be used for in situ remediation.
使用渗透性反应屏障（PRB）处理受污染的地下水存在两个最大的缺点，一是安装成本高昂，尤其是当受污染的地下水位于地表以下深处时；二是对于许多污染物羽流所需的长时间尺度（例如数十年）而言，PRB能否长期保持有效性存在不确定性。使用注入-抽出处理井对（IETWP）来捕获和处理受污染的地下水可以规避这些困难，同时仍能提供PRB所具有的许多相同优势。本文比较了IETWP和PRB的水力学特性，主要关注捕获羽流的宽度。结果表明，IETWP的作用方式与PRB类似，可作为水力屏障，并且IETWP能出色地捕获羽流。本文给出了在均质含水层中垂直于地下水流向布置的IETWP的羽流捕获宽度的数学表达式。还讨论了其他一些实际考量因素，这些因素可能决定在特定的受污染场地中IETWP是否比PRB更适用；这些考量因素包括运营和维护成本，以及IETWP系统可用于原位修复的条件。
