Article
Computer Science, Interdisciplinary Applications
Ming-Qing Peng, Shi-Jin Feng, Hong-Xin Chen, Zhang-Long Chen
Summary: This study provides an analytical solution for forecasting one-dimensional molecular diffusion of organic pollutants in a triple-layer composite liner system considering the coupling effect of thermal diffusion. The solution is verified against experimental data and a numerical method. The study investigates the performances of nine typical barrier liner systems.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Engineering, Geological
J. Qiu, Y. He, D. Song, J. Tong
Summary: Analytical solutions for contaminant transport through a 1D triple-layer composite liner system under non-isothermal conditions are derived using the generalized integral transform technique. The proposed solutions consider the combined effects of diffusion, sorption, and thermodiffusion, as well as temperature-dependent coefficients. The solutions are successfully validated against experimental results and are shown to accurately predict the transport behavior in the liner system.
GEOSYNTHETICS INTERNATIONAL
(2022)
Article
Engineering, Civil
Huaxiang Yan, Majid Sedighi, Hao Ding, Zhilin Sun, Haijian Xie
Summary: An analytical solution for the non-isothermal diffusion of organic compounds in the unsaturated GMB/CCL composite liner is proposed and tested against benchmarks for accuracy. The study shows that thermal gradient can affect contaminant diffusion through Soret effect and temperature dependent coefficient in GMB. It is indicated that transitioning from saturated to unsaturated state in the liner can significantly reduce contaminant concentration and flux.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Environmental
Ming-Qing Peng, Shi-Jin Feng, Hong-Xin Chen, Zhang-Long Chen, Hai-Jian Xie
Summary: A new analytical model for organic contaminant transport through GMB/CCL composite liner was developed, considering adsorption, diffusion, and thermodiffusion processes. The study showed that thermodiffusion has a significant impact on contaminant transport in wet landfills, and neglecting its effect can lead to overestimation of barrier performance. Additionally, thermal conductivity of GMB and CCL has negligible effect on contaminant transport in GMB/CCL composite liners.
Article
Computer Science, Interdisciplinary Applications
Ming-Qing Peng, Shi-Jin Feng, Hong-Xin Chen, Zhang-Long Chen
Summary: This paper presents a new analytical model for forecasting the one-dimensional transient transport of organic pollutants in a typical landfill composite liner. The model considers the coupling effect of molecular diffusion, thermodiffusion, advection, and linear adsorption processes. The results show that thermodiffusion significantly influences pollutant migration in the composite liner.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
Ji-Yun Chang, Shi-Jin Feng, Qi-Teng Zheng, Yang Shen
Summary: The dynamic shear mechanism of the composite liner system consisting of GMB and GCL is not clear due to limited dynamic test data. Results from cyclic shear tests suggest that the dynamic peak strength of the composite liner can generally be predicted with its static strength envelope. Proposed equations help accurately model the cyclic shear behavior, describing the dynamic softening mechanism and rate-dependent shear stiffnesses.
GEOTEXTILES AND GEOMEMBRANES
(2021)
Article
Engineering, Geological
Jun Liu, Zhang-Long Chen, Chuang Yu, Shun Wang, Wei Wu
Summary: This study presents an analytical solution to assess the effect of unsaturation-dependent retardation and capillarity on the organic contaminant diffusion through an unsaturated composite liner. It shows that neglecting saturation-dependent retardation may cause considerable errors.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Geological
Zhang-Long Chen, Jun Liu, Chuang Yu, Shun Wang, Wei Wu
Summary: This study presents an exact solution to the thermal gradient enhanced diffusion of organic contaminants through unsaturated composite liners, considering the existence of the capillary fringe. The results show that the capillary fringe has a significant influence on contaminant diffusion and the thermal effects. A simplified solution is proposed and evaluated for engineering practice. These findings are important for analyzing organic contaminants diffusion in unsaturated composite liners with the consideration of the capillary fringe and thermal effects.
Article
Computer Science, Interdisciplinary Applications
Yu-Chao Li, Shi-Yuan Yao, Cheng Chen, Yun-Min Chen, Guan-Nian Chen, Ri -Hong Zhang
Summary: Geomembranes in landfill composite liners often have long defects, which can lead to underestimation of leakage rate. In this study, a new solution considering two-dimensional flow in the compacted clay liner (CCL) was proposed to predict the leakage rate through GMB/CCL composite liners. The proposed solution showed lower relative errors for leakage rate and wetted distance compared to the existing solution.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
H. M. G. Eldesouky, R. Thiel, R. W. I. Brachman
Summary: In this study, the effects of geomembrane stiffness, fluid depth, volume of entrapped gas, and interface friction on the deformed shape and strain of the geomembrane were analyzed using three-dimensional, geometrically-nonlinear, finite-element analysis. The results showed that the deformed geomembrane followed a bell-shaped curve and the strain increased as the fluid depth increased.
GEOTEXTILES AND GEOMEMBRANES
(2023)
Article
Engineering, Geological
Qin Li, Jiannan Chen, Craig H. Benson, Daoping Peng
Summary: The high ionic strength of porewater in red mud suppresses montmorillonite swelling, making geosynthetic clay liners (GCLs) too permeable for effective use in red mud disposal facilities. Bentonite-polymer composite GCLs (BPC GCLs) have been developed as more resilient lining materials, with hydraulic conductivity influenced by the leachate's chemical properties and polymer type.
GEOTEXTILES AND GEOMEMBRANES
(2021)
Article
Geochemistry & Geophysics
Jose Humberto de Souza Prates, Jose Roberto Dantas da Silva, Filipe Milani de Souza, Davidson Martins Moreira
Summary: Two solutions for the 3D steady-state fractional advection-diffusion equation were obtained in this study to investigate the dispersion of air pollutants. The solutions showed good performance under low fractional conditions but deteriorated as the fractionality increased.
PURE AND APPLIED GEOPHYSICS
(2022)
Article
Engineering, Geological
Kejie Zhai, Hongyuan Fang, Niannian Wang, Bin Li, Jiaxiu Dong, Binghan Xue
Summary: This study used mechanical methods to analyze the composite structure of concrete pipes and liners. The research findings are important for understanding the mechanical characteristics of the composite structure and the stress state and bearing capacity of the host pipe.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Environmental
Xiang-Hong Ding, Shi-Jin Feng
Summary: This study presents an analytical model for predicting the diffusion of chlorinated solvents through multilayer aquitards. The model takes into account the slow advection and degradation of dissolved constituents in natural aquitards and the depletion of dense nonaqueous phase liquid (DNAPL) source zone in aquifers. The results suggest that advection in aquitards can significantly impact the trailing time of chlorinated solvent plumes, and adsorptive soils may mitigate this effect in layered aquitards. The proposed model provides a useful tool for remediation decisions and risk assessment in chlorinated-solvent contaminated sites.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Environmental Sciences
Hao Ding, Haijian Xie, Peifu Cai, Liang Wang, Huaxiang Yan, Aimin Jin, Yun Chen
Summary: This study develops alternative formulations for transient analytical modeling of organic contaminant transport in a composite of geosynthetic clay and attenuation layer system. The Laplace transform method is used to derive the solution. The proposed analytical frameworks are validated by benchmark tests and applied to evaluate various cases of organic contaminant transport.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Geological
Zhang-Long Chen, Shi-Jin Feng, Hong-Xin Chen, Ming-Qing Peng, Yi-Cheng Li, Zhang-Wen Zhu
Summary: An analytical solution for contaminant transport through a vertical cut-off wall and aquifer system is developed. It includes hyperbolic eigenfunctions, considers degradation processes, and is suitable for aquifers with finite thickness. The solution is verified and important conclusions are obtained, including the necessity of considering hyperbolic eigenfunctions, the approximation of regarding the aquifer as semi-infinite under certain conditions, and the significant influence of contaminant degradation on transport. This solution has better applicability than existing analytical solutions and can be used as a tool for the design of vertical slurry cut-off walls.
ENVIRONMENTAL GEOTECHNICS
(2023)
Article
Engineering, Geological
Shi-Jin Feng, Jia-Liang Shi, Yang Shen, Hong-Xin Chen, Ji-Yun Chang, Hong-Tao Wang
Summary: This paper presents an experimental study on the interface shear behavior between smooth and textured geomembranes and compacted clay liners. The shear strength was found to be mainly driven by the normal stress level and had minimal influence from the displacement rate. The residual shear strength of the textured geomembrane/compacted clay liner interface was even higher than the peak shear strength of the smooth geomembrane/compacted clay liner interface at all normal stress levels.
ENVIRONMENTAL GEOTECHNICS
(2023)
Article
Environmental Sciences
He Chen, Shi-Jin Feng, Qi-Teng Zheng, Hong-Xin Chen
Summary: This study develops a two-dimensional analytical model for enhanced delivery of amendments in a finite-domain low-permeability matrix through multi-point injection in a natural, hydraulic or pneumatic fracture. Results show that with a stronger line source formed in the fracture right after injection, the concentration distribution of amendments in the matrix is more uniform at each depth resulting in a smaller residual rate. A controlled slow-release system can maintain a more stable concentration distribution in the fracture, giving a longer residence time.
Article
Computer Science, Interdisciplinary Applications
Qi-Teng Zheng, Shi-Jin Feng, Shao-Jie Wu, Xiao-Lei Zhang, Hong-Xin Chen
Summary: A three-dimensional multifield coupled model was developed in this study to reveal the multiple field interactions in an aerobic landfill. The results showed that a certain amount of oxygen is distributed around the aeration well, while methane volume fraction decreases in most regions. The temperature in the aerobic reaction area increased up to 60 degrees Celsius, accelerating water evaporation and inhibiting the reaction. The maximum vapor volume fraction occurs at the aerobic front.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Thermodynamics
Shi-Jin Feng, He Chen, Qi-Teng Zheng, Hong-Xin Chen
Summary: This study develops a fractal theoretical model to predict the diffusion behavior of gas in heterogeneous porous media. The results show that under dry conditions, the heterogeneity of porosity significantly affects gas diffusivity, while under wet conditions, the resistance of molecular diffusion is influenced by the local heterogeneity of saturation distribution.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Environmental Sciences
Zhang-Wen Zhu, Shi-Jin Feng, Hong-Xin Chen, Zhang-Long Chen, Xiang-Hong Ding, Chun-Hui Peng
Summary: This study investigates the contamination of subsurface soil by volatile organic compounds (VOCs), focusing on petroleum hydrocarbon compound (PHC) as a typical VOC. A one-dimensional analytical model is developed to simulate the diffusion and oxygen-limited biodegradation of PHC vapor in homogeneous soil. The migration of PHC vapor is found to occur in three stages: pure aerobic zone stage, aerobic-anaerobic zones co-existence stage, and steady-state stage. The proposed analytical model should be applied in scenarios where the transient effect is significant, such as high source concentration, deep contaminant source, high biodegradation capacity, and high water saturation.
Article
Chemistry, Physical
Fu-Jiang Shi, Shi-Jin Feng, Qi-Teng Zheng, Xiao-Lei Zhang, Hong-Xin Chen
Summary: This study focused on the application of soil-bentonite slurry trench cutoff walls and found that polyanionic cellulose (PAC) modification can enhance the properties of calcium bentonite (CaB) and has the potential to replace sodium bentonite (NaB).
APPLIED CLAY SCIENCE
(2022)
Review
Engineering, Environmental
Jia Liu, Wen-yan Li, Hong-xin Chen, Shuang-qiang Li, Li-heng Yang, Kai-ming Peng, Chen Cai, Xiang-feng Huang
Summary: This review discusses the stabilization mechanisms of nanoparticle-stabilized surfactant foam (NP-SF) and the effects of nanoparticle properties on foam stability. Different types of nanoparticles, such as SiO2 and nano zero-valent iron, have been used to stabilize foam for remediation of petroleum-contaminated soils. Additionally, the efficiency and recyclability of Al2O3/Fe3O4 nanoparticles in diesel and crude oil remediation can be enhanced by applying a magnetic field. This review provides a theoretical basis and practical guidelines for developing functional NP-SF for remediation of petroleum-contaminated soils.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Computer Science, Interdisciplinary Applications
Ming-Qing Peng, Shi-Jin Feng, Hong-Xin Chen, Zhang-Long Chen
Summary: This paper presents a new analytical model for forecasting the one-dimensional transient transport of organic pollutants in a typical landfill composite liner. The model considers the coupling effect of molecular diffusion, thermodiffusion, advection, and linear adsorption processes. The results show that thermodiffusion significantly influences pollutant migration in the composite liner.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
De'an Sun, Tianyi Li, Mingqing Peng, Lei Wang, Zheng Chen
Summary: A novel semi-analytical model was proposed to investigate the migration of organic contaminants through geomembranes with defects. The presence of defects was found to substantially accelerate the migration process of contaminants to the underlying soil liner.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Shao-Jie Wu, Shi-Jin Feng, Qi-Teng Zheng, Xiao-Lei Zhang, Hong-Xin Chen
Summary: Aeration is an effective technology for shortening the landfill stabilization phase. A comprehensive 3D multi-field model is developed to understand the waste stabilization process under aeration. The model considers nitrification and denitrification processes, leachate solute transport, and time-dependent deformations. The results show that most organic carbon is discharged via gas, while nitrogen is mainly dissolved in leachate as nitrate. The stabilization process can be divided into three stages based on selected indicators, providing a practical way to evaluate landfill stabilization state.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Construction & Building Technology
Hong-Xin Chen, Qin-Pei Xue, Zhi-Peng Ma, Liang Gao, Shi-Jin Feng
Summary: In this study, a geopolymer cutoff wall backfill (GCWB) without Ordinary Portland Cement (OPC) and bentonite was developed, and its macroscopic properties and barrier performance were evaluated. The optimal material ratio with the highest unconfined compressive strength was determined to be 30FA1.2M12S, and the one with the lowest hydraulic conductivity was 40FA1.2M12S. After cured for 28 days, GCWB achieved unconfined compressive strength of 6.62 MPa and hydraulic conductivity of 4.83 x 10-11 m/s. The chemical compatibility of GCWB was favorable in Na2SO4 and CaCl2 solutions. Under dry-wet cycles, the hydraulic conductivity of GCWB increased sharply after the 1st cycle and tended to be stable in subsequent cycles. Therefore, GCWB showed desirable barrier performance and durability, indicating its potential as an antifouling cutoff wall material.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Computer Science, Interdisciplinary Applications
Hong-Xin Chen, Shi-Jin Feng, Zhang-Wen Zhu, Liang Gao, Zhang-Long Chen, Shu-Rui Wang
Summary: This study proposes an analytical solution to describe the self-weight consolidation of a two-layer soil under variable load and semi-permeable boundary condition. The solution is validated against field tests, analytical solutions, and numerical simulations. The study investigates the influence of boundary drainage capacity, self-weight, load rate, and soil layering features. It is found that the consolidation ratio difference between complete pervious and semi-permeable boundary conditions decreases with increasing semi-permeability coefficient. The excess pore pressure is affected by the self-weight, with the maximum pressure appearing below the middle depth, especially at the early stages. The dissipation of excess pore pressure is hindered when the soil layer with lower consolidation coefficient is at the bottom. A design curve for the time of consolidation completion is provided, which can serve as a useful reference in engineering practices for two-layer soil consolidation.
COMPUTERS AND GEOTECHNICS
(2023)
