可渗透反应墙的结构与设计研究

On the structure and design of permeable reactive barrier

可渗透反应墙是一种地下水修复的新兴高效技术。总结了国内外可渗透反应墙修复受污染地下水的研究成果和动态,介绍了渗透性反应墙技术的基本概念、结构类型、组成、主要材料选取,论述了其设计程序,并参考若干个国外工程实践,结合岩土工程设计理念,分析了其设计过程中存在的问题,总结了一些经验公式。可渗透反应墙的反应墙的厚度主要由地下水流速和水力停留时间来确定,高度主要由不透水层或弱透水层的埋深和厚度决定,宽度主要由污染物羽流的尺寸决定。反应介质的渗透系数与含水层渗透系数的具体倍数关系应针对现场实际情况加以试验模拟分析确定。一般来说,渗透系数是含水层渗透系数的2倍以上。

The present paper is aimed to provide a review on the upto-date advances of the permeable reactive barrier （PRB）teehnology, or known as in-situ remediation of contaminated groundwater. The said PRB technology or method has been widely used in recent years in Europe and America for removing the dissolved contaminants from the polluted water. When compared with other earlier methods, it is characterized by its in-situ remediation, long-term positive performance, low cost, in addition to its manifold remediable contaminants. Though the said PRB technology has already become mature and more and more popular as a result of application for remedying contaminated surface water in the west, little has been reported here in our country. The permeable reactive barrier （PRB）, being a kind of newly-emerging highly effective groundwater remediation technology in the world, enjoys a tremendous prospect for its development. In this paper, we would like to make a comprehensive review of up-to- date advances by covering large amounts of documents on the permeable reactive wall that can be found both at home and abroad, with a detailed summary of the research results and its practical applica- tions. At the same time, we have also made a systemieal introduction to its conception, structure, type and the main material selection, including the design process of the related technical facilities. Furthermore, we would like to give commentary on the foreign engineering practice and geotechnical engineering design concepts while making analysis of some technical problems in the design process. What is more, technical survey and summary has also been made over some experimental and empirical formulas as to the thickness of the permeable reactive barrier, which seems mainly to be determined by the groundwater velocity and hydraulic retention time. The height of the barrier tends to be mainly determined by the burying depth and thickness of impermeable layer. However, the width of the permeable reactive barrier is likely to be determined mainly by the dimensions of the pollutant plume. Permeability coefficient of the reaction medium should be determined experimentally via simulation analysis on the spot. In General, the permeability coefficient of reaction medium should be twice as great as the hydraulic conductivity of aquifer. Thus, it can be seen that the above mentioned information can provide valuable reference to the domestic engineering design practice and theoretical research in the future.