Article
Agronomy
Jose V. Gaspareto, Jocenei A. T. de Oliveira, Everton Andrade, Luiz F. Pires
Summary: Representative elementary volume (REV) is required for representative measurements of soil physical properties. The REV depends mainly on the land uses for porosity and pore connectivity. The core method showed lower REV due to the larger volume analyzed than that in the cube method. It was not possible to define a REV for degree of anisotropy. The REV obtained using the cube method was more sensitive to changes in the scale of analysis, showing an increasing trend with applied wetting and drying cycles for porosity and fractal dimension.
Article
Energy & Fuels
Wei Liu, Dongyang Han, Gang Wang, Xiangyu Chu
Summary: CT scanning is an essential tool for evaluating coal microstructure, providing non-destructive quantization and visualization. By analyzing the representative elementary volume (REV) of coal samples, a relationship between model sizes and pore structure properties has been established. The comprehensive evaluation of REV improves the rationality and reliability of coal microstructure reconstruction.
Article
Geosciences, Multidisciplinary
Chen-Xing Zhou, Ran Hu, Hang Deng, Bowen Ling, Zhibing Yang, Yi-Feng Chen
Summary: Fluid-rock dissolution is widely observed in geological systems. This study examines the effect of dissolution regimes on scaling laws by conducting microfluidic experiments on limestone. It is found that the scaling conforms to classic law in regime I (uniform) but deviates significantly in regime II (localized), due to the formation of a gas phase layer that hinders acid-rock contact. A theoretical model is proposed to describe the regime transition, which provides guidance for using scaling laws in multiphase flow environments. This work enhances the accuracy of dissolution modeling in carbon sequestration.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Energy & Fuels
Annunziata D'Orazio, Arash Karimipour, Ramin Ranjbarzadeh
Summary: In this study, a novel comparison is made between the pore-structure (PS) and representative elementary volume (REV) methods for modelling fluid flow through porous media using a second-order lattice Boltzmann method (LBM). The research findings show that the porosity and obstacle arrangement significantly affect the pressure drop, permeability, and flow patterns in the porous region. While the REV method cannot simulate the detailed fluid flow through pore structures compared to the PS method, it provides a better understanding of the flow field details around obstacles (Tortuosity). This study has important applications in improving our understanding of transport phenomena in porous media.
Article
Engineering, Geological
Zhao Wang, Tiehang Wang, Weiqin Wang, Zongxian Zhang
Summary: This paper presents a numerical procedure to determine the size of the representative elementary volume (REV) in intact rocks using a polygonal grain-based model. The study found that the REV size is influenced by the mineral volume fraction, mechanical properties, geometric heterogeneity, and can vary for different properties. The results indicate that the REV size for compressive strength has a positive dependence on heterogeneity index and slightly decreases with an increase in volume fraction of biotite.
Article
Energy & Fuels
Yufang Xue, Zhongxian Cai, Heng Zhang, Qingbing Liu, Lanpu Chen, Jiyuan Gao, Fangjie Hu
Summary: Predicting the petrophysical properties of carbonate reservoirs is challenging due to their heterogeneity and complex pore systems. This study analyzed 26 samples of vuggy dolostones and identified four types of pore systems. The heterogeneity of the carbonate reservoirs was quantitatively evaluated, and it was found that different pore systems result in variable porosities, pore structures, and heterogeneity. The study also discovered that the REV sizes of vuggy dolostones are commonly larger than traditional core plugs. A new model was established to effectively predict REV sizes based on quantitative parameters, and the results provide valuable insights into accurately evaluating the petrophysical properties of vuggy carbonate reservoirs.
Article
Engineering, Civil
Zhennan He, Fachun Liang, Jia Meng, Naiming Li
Summary: This paper investigates the migration characteristics and REV variation of LNAPL under dynamic groundwater conditions. The results indicate that the redistribution of residual pollutants is mainly influenced by the fluctuation sequence. The REV decreases as the water table rises, and the frequency distribution of the minimum So-REV becomes closer to a normal distribution. These findings provide valuable guidance for designing remediation schemes.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Chemical
Ruotong Huang, Anna L. Herring, Adrian Sheppard
Summary: The study highlights the importance of the representative elementary volume (REV) in understanding porous media, showing how different wetting-phase saturations affect porosity, specific interfacial area, and topological measures. Results also emphasize the impact of image resolution and voxel size on REV analysis.
TRANSPORT IN POROUS MEDIA
(2021)
Article
Energy & Fuels
Peng-Fei Lv, Yu Liu, Feng Liu, Wen-Zhe Yang, Han-Tao Liu, Bo Zhang, Yong-Chen Song
Summary: This study systematically evaluates the pore-based architecture and representative elementary volume (REV) sizes of 22 porous samples using X-ray CT image analysis and pore network modeling. The results show that irregular grain shapes result in larger specific areas and narrower throats in identical sand packs. Additionally, packs composed of multiple types of sands or sands with larger diameter differences have larger specific areas, smaller tortuosity, and pore spaces.
Article
Energy & Fuels
Mohamed Mahrous, Enzo Curti, Sergey Churakov, Nikolaos Prasianakis
Summary: This paper aims to obtain the petrophysical parameters of Indiana limestones in order to reduce uncertainties in core-scale reactive transport simulations of carbonate rocks. By combining high resolution tomography with pore scale calculations, the rock minimum representative volume, frequency distributions of petrophysical parameters, relationships between the parameters, and the spatial correlation model and lengths of the rock have been determined.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Water Resources
Saeid Sadeghnejad, Marcel Reinhardt, Frieder Enzmann, Pit Arnold, Bianca Brandsta, Holger Ott, Fabian Wilde, Sarah Hupfer, Thorsten Scha, Michael Kersten
Summary: The digital rock physics (DRP) workflow can be used to obtain pore-scale properties by creating a reliable digital twin of porous media. This requires reliable imaging and computing power. Determining the appropriate image resolution is challenging due to the trade-off between resolution and the representative elementary volume (REV). This study aims to estimate hydraulic pore-scale properties using the Minkowski morphological functionals and determine the effect of image resolution and artificial rebinning on the REV values.
ADVANCES IN WATER RESOURCES
(2023)
Article
Construction & Building Technology
Meicen Fan, Yue Chen, Keshu Wan
Summary: By analyzing the microstructure information of cement paste through high resolution X-Ray Computed Tomography (XCT), the Representative Elementary Volume (REV) size of hardened cement paste (HCP) can be obtained. REV size is influenced by the selected microstructure information, XCT resolution, and hydration ages, with a decreasing trend as XCT resolution improves and a first increase then decrease pattern with hydration ages.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Chemical
Jinwei Wang, Shichun Chi, Xiaoquan Shao, Xiongxiong Zhou
Summary: The study found that particle crushing and particle arrangement of rockfill materials have an impact on mechanical behavior, with larger specimen sizes resulting in lower mean values and standard deviations of mechanical parameters. The sizes of REV for different mechanical parameters vary, with the REV for the E-B constitutive model parameters being 360 x 720 mm.
Article
Engineering, Civil
Tiande Wen, Xiangsheng Chen, Yinwei Luo, Longtan Shao, Geng Niu
Summary: The pore structure characteristics and hydraulic properties of granite residual soil under different particle gradation were investigated using high-resolution X-ray computed tomography (CT) and pressure plate. The relationship between three-dimensional pore structure characteristics and hydraulic properties was quantitatively analyzed. The results showed that decreasing particle diameter led to a decrease in average pore/throat radius and CT-connected porosity, but an increase in fractal dimension, indicating a complex soil pore structure. Adding larger particles improved saturated hydraulic conductivity by increasing soil pore connectivity and decreasing fractal dimension. Furthermore, the spatial variation of micropores and complex pore structure contributed to increased water retention capacity.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Yongfei Yang, Jinlei Wang, Jianzhong Wang, Yingwen Li, Hai Sun, Lei Zhang, Junjie Zhong, Kai Zhang, Jun Yao
Summary: This study investigates the flow and dissolution processes of carbon dioxide (CO2) in underground rock formations using numerical simulations. The results show that the amount of dissolved CO2 depends on its distribution in the rock, rock porosity, permeability, injection rate, and rock wetting level. Understanding these processes is crucial for predicting the effectiveness and safety of CO2 storage.
WATER RESOURCES RESEARCH
(2023)
Editorial Material
Green & Sustainable Science & Technology
Auli Niemi, Jesus Carrera, Philippe Gouze, Chin-Fu Tsang
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2022)
Article
Computer Science, Interdisciplinary Applications
Jingjing Wang, Jesus Carrera, Maarten W. Saaltink, Cristina Valhondo
Summary: The presence of low permeability regions within porous media affects solute transport and species concentrations distribution. Multirate Mass Transfer (MRMT) models represent this anomalous transport process, which conceptualizes the medium as one mobile zone and multiple immobile zones. The numerical solution with MRMT for reactive transport is developed, incorporating chemical kinetics into the governing equations, and the efficiency of the proposed algorithm allows for significant savings in CPU time. The validity of the developed solution is tested by comparison with other numerical and analytical solutions.
COMPUTERS & GEOSCIENCES
(2022)
Article
Energy & Fuels
Jesus Carrera, Maarten W. Saaltink, Joaquim Soler-Sagarra, Jingjing Wang, Cristina Valhondo
Summary: Reactive transport (RT) is a highly multidisciplinary field that combines bio-geo-chemical reactions and transport. This paper reviews the basic conceptual issues in RT and discusses the limitations of the standard advection-dispersion equation. Alternative transport formulations and solving methods are examined. The challenges and fundamental issues in representing kinetic reactions, particularly in biochemistry, are highlighted.
Article
Engineering, Civil
Laura Martinez-Perez, Linda Luquot, Jesus Carrera, Miguel Angel Marazuela, Tybaud Goyetche, Maria Pool, Andrea Palacios, Fabian Bellmunt, Juanjo Ledo, Nuria Ferrer, Laura del Val, Philippe A. Pezard, Jordi Garcia-Orellana, Marc Diego-Feliu, Valenti Rodellas, Maarten W. Saaltink, Enric Vazquez-Sune, Albert Folch
Summary: In this study, a detailed characterization of a coastal aquifer was conducted using different methods and approaches from various hydrogeological disciplines. The findings revealed that the aquifer behaves as a multi-aquifer and reactive system, with freshwater discharging beneath saltwater at multiple depths. The impact of thin silt layers in the aquifer is significant, opening new avenues for coastal aquifer management and marine ecology.
JOURNAL OF HYDROLOGY
(2022)
Article
Water Resources
Joaquim Soler-Sagarra, Maarten W. Saaltink, Albert Nardi, Francesca De Gaspari, Jesus Carrera
Summary: This article describes a formulation called the Water Mixing Approach (WMA) to solve reactive transport problems. The WMA represents transport as mixing water instead of individual solute concentrations, simplifying calculations and decoupling transport from chemistry. The article presents the implementation of WMA in a mixed Eulerian-Lagrangian transport solver and tests its accuracy, simplicity, and efficiency in three real-world cases.
ADVANCES IN WATER RESOURCES
(2022)
Article
Engineering, Chemical
Joaquim Soler-Sagarra, Jesus Carrera, Enrique Bonet, Carles Roig, Pablo Becker
Summary: This paper proposes a formulation based on the Water Mixing Approach to model solute transport in heterogeneous porous media. The formulation takes into account the scale dependence of dispersion and the separation of mixing from spreading. It introduces velocity as an independent variable, allowing concentration to depend on time, space, and velocity. The formulation, termed the Multi-Advective Water Mixing Approach, incorporates a new mixing term between velocity classes. Experimental results demonstrate the high accuracy of the formulation in both dispersion and mixing, with the mixing process exhibiting Markovianity in space despite being modeled in time.
TRANSPORT IN POROUS MEDIA
(2023)
Letter
Multidisciplinary Sciences
Victor Vilarrasa, Silvia De Simone, Jesus Carrera, Antonio Villasenor
NATURE COMMUNICATIONS
(2022)
Article
Water Resources
Jingjing Wang, Jesus Carrera, Maarten W. Saaltink, Cristina Valhondo
Summary: Reactive transport through heterogeneous media can lead to chemical heterogeneity and chemical localization. By simulating the distribution of residence times in immobile zones, we find that reactions are more likely to occur in immobile zones with residence times comparable to or larger than reaction times.
ADVANCES IN WATER RESOURCES
(2022)
Article
Environmental Sciences
Alex Abu, Raul Carrey, Cristina Valhondo, Cristina Domenech, Albert Soler, Lurdes Martinez-Landa, Silvia Diaz-Cruz, Jesus Carrera, Neus Otero
Summary: This study evaluates the treatment effectiveness of Soil Aquifer Treatment (SAT) systems for nitrogen compounds using chemical and isotopic tools. The results show that coupled nitrification-denitrification is the main mechanism responsible for nitrogen migration and distribution. The study also reveals that the addition of a permeable reactive barrier can enhance the removal of nitrogen compounds in the SAT system.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Engineering, Civil
Tybaud Goyetche, Maria Pool, Jesus Carrera, Linda Luquot
Summary: Tidal analysis is a low-cost alternative to pumping tests for evaluating aquifer hydraulic parameters. It can be done through analytical solutions or numerical simulations. However, analytical solutions are rarely used in practice as they are based on a conceptual model that neglects important factors in real-world conditions.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Tybaud Goyetche, Linda Luquot, Jesus Carrera, Laura Martinez-Perez, Albert Folch
Summary: In coastal aquifers, seawater intrusion and submarine groundwater discharge are two opposing processes that require characterization and quantification to assess the quality and composition of the water. This study proposes a methodology using principal component analysis to identify water sources and reactions, and quantify mixing ratios and the extent of chemical reactions. The research highlights the importance of cation exchange and its impact on other reactions, as well as the spatial distribution of reactions in the aquifer.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Daniel Gutierrez-Martin, Ruben Gil-Solsona, Maarten W. Saaltink, Valenti Rodellas, Rebeca Lopez-Serna, Albert Folch, Jesus Carrera, Pablo Gago-Ferrero
Summary: This study evaluates the presence and distribution of a wide range of chemicals of emerging concern (CECs) in a Mediterranean coastal aquifer near Barcelona, Spain, and identifies potential markers and tracers for anthropogenic contamination in groundwater and seawater. The results highlight the importance of submarine groundwater discharge as a source of CECs and suggest new approaches for studying the fate and transport of pollutants.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Michela Trabucchi, Daniel Fernandez Garcia, Jesus Carrera
Summary: Wormholes are conductive channels formed in highly soluble rocks, playing a crucial role in the sustainability of saline karst aquifers. The dynamics of wormholes depend on the hydrodynamic and geochemical conditions during formation, as well as the competition for flow. However, there is a lack of direct observation and quantification of wormhole dynamics. In this study, an experimental set-up was proposed to visualize and characterize the growth of multiple wormholes, providing insights into the changes in flow and transport behavior of aquifers.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Adria Sunyer-Caldu, Barbara Benedetti, Cristina Valhondo, Lurdes Martinez-Landa, Jesus Carrera, Marina Di Carro, Emanuele Magi, M. Silvia Diaz-Cruz
Summary: The need and availability of freshwater is a major environmental issue, aggravated by climate change. Alternative sources of freshwater, such as wastewater, require extensive treatment to remove contaminants. It is urgent to develop sustainable wastewater treatment techniques and water quality assessment methods.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Tybaud Goyetche, Maria Pool, Jesus Carrera, Marc Diego-Feliu, Laura Martinez Perez, Albert Folch, Linda Luquot
Summary: This study applies a simplified numerical methodology to analyze tidal response in a Mediterranean coastal aquifer, considering both hydraulic and mechanical effects. The results demonstrate that mechanical effects play a strong role in the aquifer's response to tides.
HYDROGEOLOGY JOURNAL
(2023)
