Article
Engineering, Civil
Doron Kalisman, Alexander Yakirevich, Shaul Sorek, Tamir Kamai
Summary: This study experimentally investigates solute leaching under unsaturated conditions, and shows that pressure-wave pulse flux treatment enhances solute displacement compared to drag-dominant continuous flux treatment. The pressure waves induce higher pressure gradients and more uniform wetting, leading to increased solute mass leaching and enhanced transport.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Aronne Dell'Oca, Marco Dentz
Summary: In this study, we focus on the upscaling and prediction of ensemble dispersion in two-dimensional heterogeneous porous media, specifically transverse dispersion. We investigate the stochastic dynamics of advective particles in the heterogeneous flow field and find that transverse dispersion exhibits ultraslow diffusion due to the solenoidal character of the flow field. By analyzing particle velocities and orientations through equidistant sampling along particle trajectories obtained from direct numerical simulations, we derive a stochastic model that combines correlated Gaussian noise for transverse motion and a spatial Markov model for particle speeds. We compare the model results with detailed numerical simulations in different heterogeneous porous media.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Zhengkun Zhou, Liangsheng Shi, Yuanyuan Zha, Shuixian Wang, Baokun Xu, Lei Tian, Lanhui Zhang, Jie Tian, Ruiting Yang
Summary: In this paper, a new method for identifying preferential channels (PC) using deep learning model is proposed, training the model to improve the identification of PC locations, and demonstrating the effectiveness and stronger generalizability of the method under high heterogeneity conditions.
WATER RESOURCES RESEARCH
(2022)
Article
Engineering, Civil
Luwen Zhuang, Amir Raoof, Mojtaba G. Mahmoodlu, Sara Biekart, Riemer de Witte, Lubna Badi, Martinus Th van Genuchten, Kairong Lin
Summary: Hydrodynamic dispersion in soils is significantly influenced by soil water saturation, and there is a non-monotonic relationship between fluid saturation and solute dispersivity. The extent of non-monotonicity is more pronounced for a relatively coarse-textured sand compared to a finer sand, which helps explain some inconsistencies in the literature regarding saturation-dispersivity relationships.
JOURNAL OF HYDROLOGY
(2021)
Article
Geochemistry & Geophysics
Yan Zhu, Ziteng Cui, Kun Li, Chaoqi Wang, Zhao Li, Xueyi Zhang, Zhi Dou
Summary: This study quantitatively investigated the influence of the Peclet number and water saturation on adsorption behavior in unsaturated porous media. The results showed that water saturation had a significant influence on the complexity of the flow field, while the Peclet number had little influence on the maximum adsorption.
Article
Soil Science
Matheus P. S. Toledo, Mario M. Rolim, Renato P. de Lima, Roberta Q. Cavalcanti, Pedro F. S. Ortiz, Mauricio R. Cherubin
Summary: The study found that in sugarcane fields, an increase in soil organic carbon content led to a decrease in soil strength, while an increase in compactness resulted in higher soil strength. Additionally, an increase in silt + clay content significantly increased soil compressibility.
SOIL & TILLAGE RESEARCH
(2021)
Article
Physics, Multidisciplinary
Yi Xu, HongGuang Sun, Chuantai Qiao, Jiazhong Qian
Summary: This paper confirms the existence of anomalous diffusion in the river-groundwater system and accurately describes the solute transport process using a fractional derivative model.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Thermodynamics
Zhi Dou, Xueyi Zhang, Chao Zhuang, Yun Yang, Jinguo Wang, Zhifang Zhou
Summary: This study investigates the mass transfer of solutes through residual unsaturated porous media. The results show that the variation in residual saturation has a significant influence on the velocity spatial variability and breakthrough curves of aqueous tracer in the residual flow field. Different characteristics of solute transport are observed in different ranges of saturation, and the dispersivity of the mobile domain and the solute exchange between the mobile and immobile domains both contribute to the overall dispersivity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Na Huang, Yubao Zhang, Shengqun Han
Summary: This study investigates the effects of topological properties with local variable apertures on fluid flow and solute transport through 3D discrete fracture networks. A series of 3D DFNs with different fracture density, length, and aperture distribution were generated, and the fluid flow and solute transport were simulated. The results reveal the impact of network topology and aperture heterogeneity on fluid flow and transport processes.
Article
Mechanics
A. Alexandre, T. Guerin, D. S. Dean
Summary: The study focuses on Taylor dispersion of tracer particles in microfluidic channels with strong confinement, highlighting the influence of channel walls on diffusivity and interactions with the tracer particles. A simple and general formula is provided for calculating the effective diffusion constant along the channel and the first non-trivial finite time correction, applicable to various flow conditions, interaction potentials, and diffusion tensors. The formulas are particularly useful for numerical implementation and comparison with experiments.
Article
Biotechnology & Applied Microbiology
Rozita Soltani Tehrani, Luc Hornstra, Jos van Dam, Dirk Gijsbert Cirkel
Summary: At managed artificial recharge sites in the Netherlands, recontamination of infiltrated water with fecal indicator bacteria has been observed. The results of this study suggest that the unsaturated zone is an important barrier between microbial contamination at the soil surface and groundwater. However, bacteria that accumulate in the unsaturated zone can multiply and be released into the saturated zone during heavy rainfall or a rise in groundwater level.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Environmental Sciences
Mingbin Huang, S. Lee Barbour, M. Jim Hendry
Summary: This study developed a three-dimensional model to investigate the release of nitrate from waste rock dumps and its impact on water quality. The model showed that considering construction history and solute transport can effectively capture the mechanisms of pollutant release from waste rock dumps.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Physics, Multidisciplinary
D. R. Russell, G. C. Burdiak, J. J. Carroll-Nellenback, J. W. D. Halliday, J. D. Hare, S. Merlini, L. G. Suttle, V. Valenzuela-Villaseca, S. J. Eardley, J. A. Fullalove, G. C. Rowland, R. A. Smith, A. Frank, P. Hartigan, A. L. Velikovich, J. P. Chittenden, S. V. Lebedev
Summary: This study presents the investigation of perpendicular subcritical shocks in a collisional laboratory plasma. The shocks are generated by placing obstacles in the supermagnetosonic outflow from an inverse wire array z pinch. The existence of subcritical shocks in this regime is demonstrated, and it is found that secondary shocks form in the downstream. Detailed measurements confirm the absence of a hydrodynamic jump in the subcritical shock structure. The calculated resistive diffusion length is approximately equal to the shock width. Little heating is observed across the shock, indicating a lack of viscous dissipation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Environmental Sciences
Maosheng Yin, Kai Xiao, Pei Xin, Hailong Li, Chunmiao Zheng, Erik Smith, Alicia M. Wilson
Summary: This study investigates the impact of crab burrows on groundwater flow and salt transport in coastal wetlands. The results show that crab burrows can form complex networks of preferential flow paths, enhancing groundwater and salt circulation. The morphology of the burrows also plays a key role in the depth and intensity of burrow flushing.
WATER RESOURCES RESEARCH
(2023)
Article
Engineering, Civil
Maosheng Yin, Rui Ma, Yong Zhang, Jingjing Lin, Zhilin Guo, Chunmiao Zheng
Summary: This study conducted a field tracer test in an alluvial aquifer in Tongzhou, Beijing, China, and found that multiscale medium heterogeneity had a significant impact on solute transport. The study revealed that the impact of regional-scale heterogeneity on solute transport increased with increasing discrepancy in hydraulic conductivity between adjacent hydrofacies, while subhydrofacies-scale heterogeneity played an important role when the mean hydraulic conductivity of adjacent hydrofacies became more similar. These findings provide new insights into the control mechanism of multiscale heterogeneity on solute transport.
JOURNAL OF HYDROLOGY
(2023)