Analytical model for coupled consolidation and diffusion of organic contaminant transport in triple landfill liners

Yan, Huaxiang; Wu, Jiawei; Thomas, Hywel Rhys; Ding, Hui-Sheng; Zhan, Liangtong; Xie, Haijian

doi:10.1016/j.geotexmem.2020.10.019

Cited by 34 publications

(62 citation statements)

References 36 publications

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“…The Monte Carlo method was adopted in this section to carry out the statistical analysis of different parameters (e.g., retardation factor, degradation of contaminants, the porosity of CCL, and crack width) (Jacoboni and Reggiani 1983). The ranges of the half-width of the crack (b), the crack retardation factor (R f ), the half-life of organic contaminants in cracks (t f, 1/2 ), and the porosity of CCL (θ) was assumed to be 0-25 mm (Basnett and Brungard 1992;Xie et al 2019), 1-19 (Tang et al 1981;Yan et al 2021a), 10-90 years (Yan et al 2021a), 0.2-0.44 (Musso et al 2020), respectively. The average values of these parameters b, R f , t f,1/2 , θ are assumed to be 12.5 mm, 10, 50 years, 0.32, respectively, for the reference scenario.…”

Section: Effect Of Crack Widthmentioning

confidence: 99%

A semi-analytical solution to organic contaminants transport through composite liners considering a single crack in CCL

Xie

Ding

Yan

et al. 2022

Environ Sci Pollut Res

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Compacted clay liners (CCLs) are extensively used as engineering barriers for groundwater and soil pollution. The existence of cracks/fractures in CCL caused by thermally induced shrinkage is reported to importantly damage the performance of the CCL. An analytical model is developed to study the effects of the cracks/fractures on the migration of organic contaminants through a composite liner system. Laplace transformation and Laplace inversion using the Stehfest method are adopted to derive the analytical solution, which is validated by the experimental data. The existence of crack shows a significant impact on the breakthrough curve and bottom flux of organic contaminants. Increasing the crack width from 1 to 25 mm results in an enhancement of contaminant bottom concentration by a factor of 280. Increasing the adsorption factor and degradation rate of contaminants can effectively improve the performance of the composite liner with cracks. The effects of degradation of contaminants on the breakthrough curve are found to be more significant for the case with a larger retardation factor. This may be due to the fact that increasing the retardation factor can significantly slow down the transport of contaminants, which may indirectly create a longer period for the degradation of contaminants.

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Section: Effect Of Crack Widthmentioning

confidence: 99%

A semi-analytical solution to organic contaminants transport through composite liners considering a single crack in CCL

Xie

Ding

Yan

et al. 2022

Environ Sci Pollut Res

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“…The mathematical model is a basic tool used to study the contaminant transport process and laws, and is an important theoretical foundation in the field of environmental geotechnical engineering [1,2]. The hydrodynamic dispersion equation is the basic differential equation of contaminant migration in porous media [23][24][25][26][27], and the mathematical model consists of the basic differential equation, initial conditions and boundary conditions that describe the contaminant migration in actual problems [28].…”

Section: A the Basic Model And Its Solutionmentioning

confidence: 99%

“…For example, the breakthrough time is calculated using a numerical method under different conditions for the design of seepage curtain thickness [13], and the finite element method is commonly used by establishing a grid model and defining the initial and boundary conditions, but the calculation process is usually time-consuming and complex [21,22]. In the second approach, an analytical solution is given by constructing the initial and boundary conditions of the mathematical model based on a one-dimensional convective dispersion equation [13,15,23,24]. However, the traditional mathematical analysis method of solving partial differential equations is also very complex [25,26], and it is more complicated in engineering applications as a result of the difficulty and cost of anti-seepage layer design and management.…”

Section: Introductionmentioning

confidence: 99%

Research on the Contaminant Breakthrough Time Algorithm Based on Thermal Penetration Theory

Lin¹,

Ren

Wei

et al. 2021

IEEE Access

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The current calculation method of breakthrough time calculates the concentration value of the measuring point at different times based on the model solution, which is determined by approaching the concentration value corresponding to the breakthrough standard through trial calculations. However, it is necessary to research the breakthrough standard with practical applications of mathematical and physical significance, especially a one-dimensional mathematical model of contaminant migration under Dirichlet boundary conditions. A general algorithm for directly calculating the breakthrough time was established in this research. Moreover, the calculation standard of the breakthrough time was also discussed based on the similarity between the analytical solution and the mathematical law of thermal conduction. This research considered parameters of the seepage velocity, dispersion coefficient and characteristics of the impervious layer, and the sensitivity analysis of these factors were investigated. The results show that the proposed algorithm was basically consistent with the current method, and the concept of thermal penetration depth is also feasible for the calculation standard. This is not only suitable for different breakthrough standards, but also simple and convenient. This study can provide a reference for the design, management and subsequent remediation of actual sites. INDEX TERMSBreakthrough time, mathematical model, convection dispersion, analytical solution, general algorithm. I.

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“…Many studies in recent decades have been conducted to investigate the effect of consolidation on solute transport through single clay liner or composite liner system (e.g., CCL, GMBL/CCL and GMBL/GCL/CCL) including field studies, 10 experimental investigations 11–14 and numerical analysis 4,7–9,15–26 . The above studies highlighted the importance of consolidation on contaminant transport through the liner system.…”

Section: Introductionmentioning

confidence: 99%

Analytical solution for one‐dimensional steady‐state contaminant transport through a geomembrane layer (GMBL)/compacted clay layer (CCL)/attenuation layer (AL) composite liner considering consolidation

Yan

Xie

Ding

et al. 2022

Num Anal Meth Geomechanics

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A composite liner system consisting of a geomembrane layer (GMBL), a compacted clay layer (CCL) and an attenuation layer (AL) is widely used in the modern landfills. The field and experimental observations highlight the potential detrimental effects on breakthrough of contaminants induced by consolidation of soil liner when a relatively high applied stress is caused by the waste placement. A one dimensional steady‐state model is developed to investigate the behaviour of contaminant transport in GMBL/CCL/AL composite liner system considering consolidation. Effects of the consolidation process on the transport of typical contaminants are investigated by the proposed analytical solution. The analytical results show that the magnitude of volume compressibility coefficient in the AL is important in controlling the overall magnitude of the consolidation induced effects. The process of consolidation shows a larger impact on the absorbable pollutants compared to the non‐absorbable pollutants. This may be due to the fact that the migration of solid particles induced by the consolidation may assist the transport of contaminant absorbed on them. The thickness of the AL shows large impacts on the bottom flux for the case with a high volume compressible coefficient. Increasing the thickness of AL from 1 to 3 m can results in a factor of 2.6 increase of the bottom flux. Increasing the thickness of the AL leads to a larger consolidation advection and a longer consolidation path, which may be the dominant mechanisms for contaminant transport compared to the diffusion process.

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Analytical model for coupled consolidation and diffusion of organic contaminant transport in triple landfill liners

Cited by 34 publications

References 36 publications

A semi-analytical solution to organic contaminants transport through composite liners considering a single crack in CCL

A semi-analytical solution to organic contaminants transport through composite liners considering a single crack in CCL

Research on the Contaminant Breakthrough Time Algorithm Based on Thermal Penetration Theory

Analytical solution for one‐dimensional steady‐state contaminant transport through a geomembrane layer (GMBL)/compacted clay layer (CCL)/attenuation layer (AL) composite liner considering consolidation

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