摘要
可渗透反应墙(Permeable Reactive Barrier,PRB)技术是原位地下水或者土壤修复中最受瞩目的技术之一,该技术设计和安装的首要关键问题就是反应墙的厚度计算.现有的反应墙设计方法大部分只考虑了单一污染物或者反应墙本身,很少考虑多种污染物的存在以及含水层水力性质的实际情况.聚焦于可渗透反应墙中的PCE(四氯乙烯)链式降解过程,基于可渗透反应墙-含水层的多域多组分污染物的体系建立了一维条件下的对流弥散方程,通过借鉴相关文献提出的转换算法得出方程解析解,并由此推导出适合多组分污染物体系的反应墙厚度公式,利用软件COMSOL建立了数值模型验证了其正确性.对比已有的Rabideau模型发现:计算反应墙厚度时不能完全忽略含水层的自然衰减反应,尤其当达标面远离反应墙出口处时;对于多种组分皆来源于同一种母源反应物的污染物,计算反应墙厚度时边界条件十分关键.本文模型的解析解可以为可渗透反应墙的设计和安装提供建设性的意见,还可以快速分析多组分污染物的分布和预测,为地下水的修复工程、风险评估、后期监测控制提供了计算的支撑.
Permeable Reactive Barrier(PRB) technology is one of the most popular technologies for in-situ groundwater or soil remediation. A key task of design and installation is to calculate the thickness of the PRB. Most of the existing models of calculating the PRB thickness only consider the single species or the reaction barrier itself, with little consideration of a variety of contaminants and the combination of the aquifers. The response to PRB and aquifer multi-domain system, the convection dispersion equation of multi-species under one-dimensional condition was established. The analytical solution of the equation was obtained by using a conversion algorithm proposed by related literature, and the formula of the new PRB thickness was deduced at the same time, and then the numerical model was built based on the software COMSOL to validate this analytical solution. After comparing the required PRB thickness calculated from this study and previously developed Rabideau models, the aquifer reaction capability is found to be non-negligible for the determination of the required thickness of the PRB especially when the compliance plane becoming far from the PRB exit face. For the remediation multiple species sharing a single parental species, the correctness in the boundary and the domain conditions are crucial to estimate the effective thickness of a PRB. The proposed analytical solution provides meaningful designing insights for the PRB design and installation.
作者
陈华丽
胡成
陈刚
王挺
吴礼光
Chen Huali;Hu Cheng;Chen Gang;Wang Ting;Wu Liguang(School of Environmental Science and Engineering,Zhejiang Gongshang University,Hangzhou 310018,China;School of Environmental Studies,China University of Geosciences,Wuhan 430078,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2021年第8期3012-3018,共7页
Earth Science
基金
国家自然科学基金青年基金项目(No.41401539)。
关键词
可渗透反应墙
一维流动
四氯乙烯
解析解
反应墙厚度
环境科学
Permeable Reactive Barrier(PRB)
1D flow
PCE
analytical solution
PRB thickness
environmental science
