A novel permeable reactive barrier(PRB)configuration,the so-called passive convergence-permeable reactive barrier(PC-PRB),is proposed to overcome several shortcomings of traditional PRB configurations,such as high dependency to site hydrogeological characteristics and plume size.The PC-PRB is designed to make the plume converge towards the PRB due to the passive hydraulic decompression-convergent flow effect.The corresponding passive groundwater convergence(PC)system is deployed upstream of the PRB system,which consists of passive wells,water pipes,and a buffer layer.A two-dimensional(2D)finite-difference hydrodynamic code,entitled PRB-Flow,is developed to examine the hydraulic performance parameters(i.e.,capture width(W)and residence time(t))of PC-PRB.It is proved that the horizontal 2D capture width(W))and vertical 2D capture depth(W)of the PC-PRB remarkably increase compared to that of the continuous reactive barrier(C-PRB).The aforementioned relative growth values in order are greater than 50％and 25％in this case study.Therefore,the PRB geometric dimensions as well as the materials cost required for the same plume treatment lessens.The sensitivity analysis reveals that the dominant factors influencing the hydraulic performance of the PC-PRB are the water pipe length(Lp),PRB length(LLPRB),passive well height(Hw),and PRB height(HHPRB).The discrepancy between the Wh of PC-PRB and that of the C-PRB(i.e.,AWh)has a low correlation with PRB parameters and mainly depends on Lp,which could dramatically simplify the PC-PRB design procedure.Generally,the proposed PC-PRB exhibits an effective PRB configuration to enhance hydraulic performance.

Kaixuan Zheng;Xingshen Luo;Yiqi Tan;Zhonglei Li;Hongtao Wang;Tan Chen;Li Zhao;Liangtong Zhan

School of Environment,Tsinghua University,Beijing 100084,China;College of Life and Environmental Sciences,Minzu University of China,Beijing 100081,China;Institute of Geotechnical Engineering,College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China

环境科学与工程前沿

[1]Kaixuan Zheng;Xingshen Luo;Yiqi Tan;Zhonglei Li;Hongtao Wang;Tan Chen;Li Zhao;Liangtong Zhan-.Passive convergence-permeable reactive barrier(PC-PRB):An effective configuration to enhance hydraulic performance)[J].环境科学与工程前沿,2022(12):76-85

lessens,LLPRB,HHPRB,AWh

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