Analytical study of nonlinear consolidation effect on contaminant transport in an aquitard coupling diffusion and adsorption

IF 4 2区环境科学与生态学 Q1 WATER RESOURCES

Advances in Water Resources Pub Date : 2025-02-06 DOI:10.1016/j.advwatres.2025.104912

Zhaofeng Li , Xi Zou , Wen Zhang , Xiaoli Wu , Yue Hu , Genxu Wang , Walter A. Illman

{"title":"Analytical study of nonlinear consolidation effect on contaminant transport in an aquitard coupling diffusion and adsorption","authors":"Zhaofeng Li , Xi Zou , Wen Zhang , Xiaoli Wu , Yue Hu , Genxu Wang , Walter A. Illman","doi":"10.1016/j.advwatres.2025.104912","DOIUrl":null,"url":null,"abstract":"<div><div>Aquitards, which widely occur throughout sedimentary basins or alluvial plains, play important roles in groundwater storage and contaminant transport. In this study, a mathematical model for one-dimensional contaminant transport which considered the combined effects of diffusion, adsorption and nonlinear consolidation deformation processes in an aquitard (NCD model) was formulated. An analytical solution was then derived using the separation variable method and the generalized integral transformation technique approach, and the accuracy of the above analytical solution was verified by a numerical model. During the nonlinear consolidation process of the aquitard, the drawdown, Darcy velocity and void ratio remained unstable until the end of consolidation, and contaminants entry into the aquitard exhibited hysteresis influenced by aquitard consolidation. Increasing drawdown of the adjacent confined aquifer, compression index, initial hydraulic conductivity, initial effective stress of the aquitard as well as decreasing values of aquitard thickness, initial void ratio and partitioning coefficient were all found to reduce the breakthrough time of contaminant transport in an aquitard undergoing nonlinear consolidation. Compared with contaminant transport in non-deforming porous medium, where transport parameters identical to those of the aquitard before consolidation (ND model) and after finishing consolidation (NDf model), the breakthrough time of contaminant transport for the NCD model (133.3 years) was significantly greater than that of the ND model (68.9 years), and it was slightly less than that of the NDf model (140.6 years). The difference in breakthrough times, at which the contaminants reach 0.01 times the initial concentration, between the NCD and NDf models had an obvious linear positive correlation with the consolidation factor and the cumulative water release from the aquitard.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"197 ","pages":"Article 104912"},"PeriodicalIF":4.0000,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Water Resources","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0309170825000260","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"WATER RESOURCES","Score":null,"Total":0}

引用次数: 0

Abstract

Aquitards, which widely occur throughout sedimentary basins or alluvial plains, play important roles in groundwater storage and contaminant transport. In this study, a mathematical model for one-dimensional contaminant transport which considered the combined effects of diffusion, adsorption and nonlinear consolidation deformation processes in an aquitard (NCD model) was formulated. An analytical solution was then derived using the separation variable method and the generalized integral transformation technique approach, and the accuracy of the above analytical solution was verified by a numerical model. During the nonlinear consolidation process of the aquitard, the drawdown, Darcy velocity and void ratio remained unstable until the end of consolidation, and contaminants entry into the aquitard exhibited hysteresis influenced by aquitard consolidation. Increasing drawdown of the adjacent confined aquifer, compression index, initial hydraulic conductivity, initial effective stress of the aquitard as well as decreasing values of aquitard thickness, initial void ratio and partitioning coefficient were all found to reduce the breakthrough time of contaminant transport in an aquitard undergoing nonlinear consolidation. Compared with contaminant transport in non-deforming porous medium, where transport parameters identical to those of the aquitard before consolidation (ND model) and after finishing consolidation (ND_f model), the breakthrough time of contaminant transport for the NCD model (133.3 years) was significantly greater than that of the ND model (68.9 years), and it was slightly less than that of the ND_f model (140.6 years). The difference in breakthrough times, at which the contaminants reach 0.01 times the initial concentration, between the NCD and ND_f models had an obvious linear positive correlation with the consolidation factor and the cumulative water release from the aquitard.

Abstract Image

查看原文本刊更多论文

非线性固结效应对水体中污染物运移的影响分析研究

在沉积盆地或冲积平原中广泛存在的含水层在地下水的储存和污染物的运移中起着重要的作用。本文建立了考虑水体中扩散、吸附和非线性固结变形过程综合影响的一维污染物运移数学模型（NCD模型）。采用分离变量法和广义积分变换方法推导了解析解，并通过数值模型验证了解析解的准确性。在含水层的非线性固结过程中，沉降、达西速度和空隙比在固结结束前保持不稳定，进入含水层的污染物受含水层固结的影响表现出滞后性。研究发现，在非线性固结过程中，随着邻近承压含水层降深的增大、压缩指数的增大、含水层初始导水率的增大、含水层初始有效应力的增大，含水层厚度、初始空隙率和分配系数的减小，污染物在含水层中运移的突破时间缩短。在固结前（ND模型）和完成固结后（NDf模型）输运参数相同的非变形多孔介质中，NCD模型的污染物输运突破时间（133.3年）显著大于ND模型（68.9年），略小于NDf模型（140.6年）。NCD模型和NDf模型在污染物达到初始浓度0.01倍时的突破次数差异与固结系数和含水层累积放水量呈明显的线性正相关。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Advances in Water Resources 环境科学-水资源

CiteScore

9.40

自引率

6.40%

发文量

171

审稿时长

36 days

期刊介绍： Advances in Water Resources provides a forum for the presentation of fundamental scientific advances in the understanding of water resources systems. The scope of Advances in Water Resources includes any combination of theoretical, computational, and experimental approaches used to advance fundamental understanding of surface or subsurface water resources systems or the interaction of these systems with the atmosphere, geosphere, biosphere, and human societies. Manuscripts involving case studies that do not attempt to reach broader conclusions, research on engineering design, applied hydraulics, or water quality and treatment, as well as applications of existing knowledge that do not advance fundamental understanding of hydrological processes, are not appropriate for Advances in Water Resources. Examples of appropriate topical areas that will be considered include the following: • Surface and subsurface hydrology • Hydrometeorology • Environmental fluid dynamics • Ecohydrology and ecohydrodynamics • Multiphase transport phenomena in porous media • Fluid flow and species transport and reaction processes