Diffusive mass exchange of non-reactive substances in dual-porosity porous systems - column experiments under saturated conditions

2015 ◽  
Vol 30 (6) ◽  
pp. 914-926 ◽  
Author(s):  
Bastian Knorr ◽  
Piotr Maloszewski ◽  
Florian Krämer ◽  
Christine Stumpp
Keyword(s):  
Mass Exchange ◽  
Dual Porosity ◽  
Column Experiments

Modeling wicking in textiles using the dual porosity approach

2018 ◽  
Vol 89 (17) ◽  
pp. 3519-3528 ◽  
Author(s):  
Marcelo Parada ◽  
Xiaohai Zhou ◽  
Dominique Derome ◽  
Rene Michel Rossi ◽  
Jan Carmeliet
Keyword(s):  
Moisture Content ◽  
Water Uptake ◽  
Mass Exchange ◽  
Dual Porosity ◽  
Richards Equation ◽  
Pore System ◽  
Complex Dynamic ◽  
Textile Structure ◽  
Cotton Textiles ◽  
Maximum Moisture Content

We develop a dual porosity diffusivity model to simulate the complex dynamic wicking behavior in textiles: wicking inside yarns coupled with wicking in the voids in between the yarns. The model expands the Richards equation to account for mass exchange between the two pore systems. This exchange, however, appears to be very small for cotton textiles and the system appears to behave as two parallel pore systems. The water uptake in the yarn pore system is mostly affected by the textile structure (woven versus knit), while the void pore system differs in the maximum moisture content that can be achieved during uptake. Gravity is shown to play an important role, especially for the coarser void pore system.

scholarly journals A dual porosity model of high-pressure gas flow for geoenergy applications

2018 ◽  
Vol 55 (6) ◽  
pp. 839-851 ◽  
Author(s):  
L.J. Hosking ◽  
H.R. Thomas ◽  
M. Sedighi
Keyword(s):  
High Pressure ◽  
Carbon Sequestration ◽  
Mass Exchange ◽  
Gas Flow ◽  
Gas Transport ◽  
Fracture Network ◽  
Porous Matrix ◽  
Transport Processes ◽  
Dual Porosity ◽  
Geological Carbon Sequestration

This paper presents the development of a dual porosity numerical model of multiphase, multicomponent chemical–gas transport using a coupled thermal, hydraulic, chemical, and mechanical formulation. Appropriate relationships are used to describe the transport properties of nonideal, reactive gas mixtures at high pressure, enabling the study of geoenergy applications such as geological carbon sequestration. Theoretical descriptions of the key transport processes are based on a dual porosity approach considering the fracture network and porous matrix as distinct continua over the domain. Flow between the pore regions is handled using mass exchange terms and the model includes equilibrium and kinetically controlled chemical reactions. A numerical solution is obtained with a finite element and finite difference approach and verification of the model is pursued to build confidence in the accuracy of the implementation of the dual porosity governing equations. In the course of these tests, the time-splitting approach used to couple the transport, mass exchange, and chemical reaction modules is shown to have been successfully applied. It is claimed that the modelling platform developed provides an advanced tool for the study of high-pressure gas transport, storage, and displacement for geoenergy applications involving multiphase, multicomponent chemical–gas transport in dual porosity media, such as geological carbon sequestration.

Rates of Aluminum Dissolution in Acid Sandy Soils Observed in Column Experiments

1992 ◽  
Vol 21 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Hans J.M. Grinsven ◽  
Willem H. Riemsdijk ◽  
René Otjes ◽  
Nico Breemen
Keyword(s):  
Sandy Soils ◽  
Column Experiments

Application of iron-coated sand on the treatment of toxic metals

2004 ◽  
Vol 4 (5-6) ◽  
pp. 335-341 ◽  
Author(s):  
Jae-Kyu Yang ◽  
Yoon-Young Chang ◽  
Sung-Il Lee ◽  
Hyung-Jin Choi ◽  
Seung-Mok Lee
Keyword(s):  
Heavy Metals ◽  
Selective Adsorption ◽  
Complete Removal ◽  
Batch Adsorption ◽  
Column Experiments ◽  
Adsorption Behaviour ◽  
Optimum Amount ◽  
Initial Ph ◽  
New Treatment ◽  
Coated Sand

Iron-coated sand (ICS) prepared by using FeCl3 and Joomoonjin sand widely used in Korea was used in this study. In batch adsorption kinetics, As(V) adsorption onto ICS was completed within 20 minutes, while adsorption of Pb(II), Cd(II), and Cu(II) onto ICS was slower than that of As(V) and strongly depended on initial pH. At pH 3.5, ICS showed a selective adsorption of Pb(II) compared to Cd( II) and Cu(II) . However, above pH 4.5, near complete removal of Pb(II), Cd(II), and Cu(II) was observed through adsorption or precipitation depending on pH. As(V) adsorption onto ICS occurred through an anionic-type and followed a Langmuir-type adsorption behaviour. In column experiments, pH was identified as an important parameter in the breakthrough of As(V). As(V) breakthrough at pH 4.5 was much slower than at pH 9 due to a strong chemical bonding between As(V) and ICS as similar with batch adsorption behaviour. With variation of ICS amounts, the optimum amount of ICS at pH 4.5 was identified as 5.0 grams in this research. At this condition, ICS could be used to treat 200 mg of As(V) with 1 kg of ICS until 50 ppb of As(V) appeared in the effluent. In this research, as a new treatment system, ICS can be potentially used to treat As(V) and cationic heavy metals.

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