The seepage regulation mechanism of passive convergence-permeable reactive barrier
ZHENG Kai-xuan1, TAO Shi-yang1, DING Jie1, CHEN Di1, TAN Yi-qi2, LEI Lei1, CHEN Yan-zhi1, WANG Wei1, WEN Yong1, PENG Xiang-qin1, WANG Hong-tao2
1. State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Science, Ministry of Ecological Environment, Guangzhou 510655, China; 2. School of Environment, Tsinghua University, Beijing 100084, China
摘要 Passive convergence-permeable reactive barrier (PC-PRB) is a novel and sustainable in-situ remediation technology for contaminated groundwater. To evaluate the hydraulic capture performance of PC-PRB and reveal its seepage regulation mechanism, we developed a PRB-Flow simulation software with high accuracy of particle tracing algorithm and strong numerical solution stability. Under the specified simulation conditions, the PC-PRB exhibited an approximately 47% increase in planar capture flow rate and a 90% increase in sectional capture flow rate compared to the continuous permeable reactive barrier (C-PRB). Sensitivity analysis showed that the water pipe length Lp, the horizontal range of the passive well TDw and the passive well depth Hw were the key parameters affecting the hydraulic performance of PC-PRB. There was a significant positive correlation between Lp and the hydraulic capture performance of PC-PRB (P<0.01). Increasing TDw and Hw can enhance the hydraulic capture capacity of PC-PRB, but the influence degree was not as significant as Lp. The drainage and depressurization effect of the water pipe makes the head drop in the passive well, which drives the surrounding groundwater to converge into the well, thus significantly improving the hydraulic capture performance of PC-PRB. PC-PRB can effectively solve the local breakthrough problem of C-PRB caused by uneven flow velocity.
Abstract：Passive convergence-permeable reactive barrier (PC-PRB) is a novel and sustainable in-situ remediation technology for contaminated groundwater. To evaluate the hydraulic capture performance of PC-PRB and reveal its seepage regulation mechanism, we developed a PRB-Flow simulation software with high accuracy of particle tracing algorithm and strong numerical solution stability. Under the specified simulation conditions, the PC-PRB exhibited an approximately 47% increase in planar capture flow rate and a 90% increase in sectional capture flow rate compared to the continuous permeable reactive barrier (C-PRB). Sensitivity analysis showed that the water pipe length Lp, the horizontal range of the passive well TDw and the passive well depth Hw were the key parameters affecting the hydraulic performance of PC-PRB. There was a significant positive correlation between Lp and the hydraulic capture performance of PC-PRB (P<0.01). Increasing TDw and Hw can enhance the hydraulic capture capacity of PC-PRB, but the influence degree was not as significant as Lp. The drainage and depressurization effect of the water pipe makes the head drop in the passive well, which drives the surrounding groundwater to converge into the well, thus significantly improving the hydraulic capture performance of PC-PRB. PC-PRB can effectively solve the local breakthrough problem of C-PRB caused by uneven flow velocity.
[1] 严芳敏,郭明帅,王 菲.炭铁材料修复三氯乙烯污染地下水的性能 [J]. 中国环境科学, 2024,44(2):825-831. Fan F M, Guo M S, Wang F. The performance of biochar/nZVI composite in remediating trichloroethylene contaminated groundwater [J]. China Environmental Science, 2024,44(2):825-831. [2] 杨茸茸,周 军,吴 雷,等.可渗透反应墙技术中反应介质的研究进展 [J]. 中国环境科学, 2021,41(10):4579-4587. Yang R R, Zhou J, Wu L et al. Research progress of reaction mediums in permeable reaction barrier technology [J]. China Environmental Science, 2021,41(10):4579-4587. [3] Gibert O, Assal A, Devlin H, et al. Performance of a field-scale biological permeable reactive barrier for in-situ remediation of nitrate-contaminated groundwater [J]. Science of The Total Environment, 2019,659:211-220. [4] Jiang Y, Xi B, Li R, et al. Advances in Fe(III) bioreduction and its application prospect for groundwater remediation: A review [J]. Frontiers of Environmental Science & Engineering, 2019,13(6):89. [5] 郑凯旋,黄俊龙,罗兴申,等.数值模拟在可渗透反应墙设计中的应用研究进展 [J]. 环境工程, 2022,40(6):22-30. Zheng K X, Huang J L, Luo X S, et al. Application progress of numerical simulation in permeable reaction barrier engineering design [J]. Environmental Engineering, 2022,40(6):22-30. [6] Ali A, Abd Ali Z. Sustainable use of concrete demolition waste as reactive material in permeable barrier for remediation of groundwater: Batch and continuous study [J]. Journal of Environmental Engineering, 2020,146:04020048. [7] Faisal A, Abdul-Kareem M, Kareem Mohammed P, et al. Humic acid coated sand as a novel sorbent in permeable reactive barrier for environmental remediation of groundwater polluted with copper and cadmium ions [J]. Journal of Water Process Engineering, 2020,36:101373. [8] Falciglia P P, Gagliano E, Brancato V, et al. Microwave based regenerating permeable reactive barriers (MW-PRBs): Proof of concept and application for Cs removal [J]. Chemosphere, 2020,251:126582. [9] 钱 程,张卫民.PRB反应介质材料在地下水污染修复中的应用研究进展 [J]. 环境工程, 2018,36(6):1-5. Qian C, Zhang W M. Progress of application of PRB reaction medium materials in remediation of contaminated groundwater [J]. Environmental Engineering, 2018,36(6):1-5. [10] 李传维,丁浩然,陈 成,等.可渗透反应墙技术在固废填埋场渗滤液处理中的应用 [J]. 环境工程学报, 2023,17(2):625-634. Li C W, Ding H R, Chen C. Application of permeable reactive barrier technology in treatment of solid waste landfill leachate [J]. Chinese Journal of Environmental Engineering, 2023,17(2):625-634. [11] Li Y, Huang Y, Wu W, et al. Research and application of arsenic-contaminated groundwater remediation by manganese ore permeable reactive barrier [J]. Environmental Technology, 2019,42:1-36. [12] Bekele D N, Du J, de Freitas L G, et al. Actively facilitated permeable reactive barrier for remediation of TCE from a low permeability aquifer: Field application [J]. Journal of Hydrology, 2019,572:592-602. [13] Obiri-Nyarko F, Grajales-Mesa S J, Malina G. An overview of permeable reactive barriers for in situ sustainable groundwater remediation [J]. Chemosphere, 2014,111:243-259. [14] Thakur A K, Vithanage M, Das D B, et al. A review on design, material selection, mechanism, and modelling of permeable reactive barrier for community-scale groundwater treatment [J]. Environmental Technology & Innovation, 2020,19:100917. [15] Higgins M, Olson T. Life-cycle case study comparison of permeable reactive barrier versus pump-and-treat remediation [J]. Environmental Science & Technology, 2009,43:9432-9438. [16] Faisal A, Sulaymon A, Khaliefa Q. A review of permeable reactive barrier as passive sustainable technology for groundwater remediation [J]. International Journal of Environmental Science and Technology, 2017,15:1123-1138. [17] Bortone I, Chianese S, Erto A, et al. An optimized configuration of adsorptive wells for the remediation of an aquifer contaminated by multiple aromatic hydrocarbon pollutants [J]. Science of The Total Environment, 2019,696:133731. [18] Torregrosa M, Schwarz A, Nancucheo I, et al. Evaluation of the bio-protection mechanism in diffusive exchange permeable reactive barriers for the treatment of acid mine drainage [J]. Science of The Total Environment, 2019,655:374-383. [19] Santonastaso G, Bortone I, Chianese S, et al. Application of a discontinuous permeable adsorptive barrier for aquifer remediation. A comparison with a continuous adsorptive barrier [J]. Desalination and Water Treatment, 2016,57(48):23372-23381. [20] Vermeul V, Szecsody J, Fritz B, et al. An injectable apatite permeable reactive barrier for in situ 90Sr immobilization [J]. Groundwater Monitoring & Remediation, 2014,34(2):28-41. [21] 王泓泉.污染地下水可渗透反应墙(PRB)技术研究进展 [J]. 环境工程技术学报, 2020,10(2):251-259. Wang H Q. Study on permeable reactive barrier technology for the remediation of polluted groundwater [J]. Journal of Environmental Engineering Technology, 2020,10(2):251-259. [22] 刁文钦,宋 健,王 琳,等.利用生物渗透性反应墙修复地下水Cr(VI)污染的数值模拟 [J]. 中国环境科学, 2022,42(7):3234-3243. Diao W Q, Song J, Wang L, et al. Numerical simulation of groundwater remediation of hexavalent chromium contaminated site by the bio-permeable reactive barrier [J]. China Environmental Science, 2022,42(7):3234-3243. [23] Bortone I, Di Nardo A, Di Natale M, et al. Remediation of an aquifer polluted with dissolved tetrachloroethylene by an array of wells filled with activated carbon [J]. Journal of Hazardous Materials, 2013,260:914-920. [24] 罗兴申,郑凯旋,许芳铭,等.数值模拟减压集流式可渗透反应墙技术修复地下水 [J]. 中国环境科学, 2021,41(12):5728-5735. Luo X S, Zheng K X, Xu F M, et al. Numerical simulation for remediation of polluted ground water by a novel convergent flow permeable reactive barrier [J]. China Environmental Science, 2021,41 (12):5728-5735. [25] Park E, Zhan H. Hydraulics of a finite-diameter horizontal well with wellbore storage and skin effect [J]. Advances in Water Resources, 2002,25(4):389-400. [26] Gupta N, Fox T C. Hydrogeologic modeling for permeable reactive barriers [J]. Journal of Hazardous Materials, 1999,68(1):19-39. [27] Liu S, Xingang L, Wang H. Hydraulics analysis for groundwater flow through permeable reactive barriers [J]. Environmental Modeling & Assessment, 2011,16:591-598. [28] Singh R, Chakma S, Birke V. Numerical modelling and performance evaluation of multi-permeable reactive barrier system for aquifer remediation susceptible to chloride contamination [J]. Groundwater for Sustainable Development, 2020,10:100317.
