Column tests are a widely use experimental tool to investigate particle transport in porous media. However, different experiments can produce similar breakthrough curves, which make these data insufficient in order to understand the governing processes that control particle transport under different conditions. Profile analysis of the deposited particles provides information about the particle...
The Gibbs energy of nanocrystals increases with decreasing crystal size due to an increasing surface to volume ratio (A/V) resulting in a solubility increase and a melting temperature decrease of small crystals. In the case of pure phases, the melting temperature decrease may be approximately represented by the Gibbs–Thomson (GT) equation. However, the melt of a salt hydrate is not a pure...
Nanoremediation is an innovative environmental nanotechnology aimed at reclaiming contaminated aquifers. It consists in the subsurface injection of a reactive colloidal suspension for the in-situ treatment of pollutants. The greatest challenges faced by engineers to advance nanoremediation are the effective delivery and the appropriate dosing of the nanoparticles into the subsoil. These are...
A profound change in transport behaviors in porous media occurs for nano- and micro-particles (herein called colloids) in the presence versus absence of repulsion between colloids and collectors (porous media grains). This change is indicated by extended tailing of low colloid concentrations during elution, which is absent or present when repulsion is absent or present, respectively. It also...
Foodborne illnesses involving fresh produce have been increasingly causing concerns around the world. Pathogenic bacteria can attach to and colonize the surfaces of fresh produce, leading to contamination and illness outbreaks. however, mechanistic interactions between produce surface properties (e.g. roughness, topography and hydrophobicity) and bacterial retention remain poorly understood....
Nanoscale roughness (NR) is a physical heterogeneity on all surfaces, whereas chemical heterogeneity (CH) may sometimes arise from spatial variability in charge (CH1), Hamaker constant (CH2), and contact angles (CH3). Expressions were developed to determine the mean interaction energy between a colloid and a solid-water interface, or another colloid, when both surfaces contain binary NR and...
Colloidal particles released by various chemical and industrial processes penetrate soils and groundwater, and transport themselves other contaminants like heavy metals or PCBs. Thus, an accurate description of the transport and retention of these particles is required to prevent and manage environmental contamination, like the pollution of drinking water supplies. Literature stands that...
CO2 injection into reservoirs will change the state of stress in both reservoir and caprock formations due to poro-mechanical, thermal and chemical effects. As a result of induced stress, the caprock can be mechanically damaged or new fracture systems can be created. It is the objective of this study to determine the behavior of intact and fractured caprock when exposed to supercritical CO2 at...
Hydraulic fracturing is a major means to improve gas production which can form multi fractures and complex fracture network. Because of the permeability difference between the fracture network zone and the matrix zone, the composite fracture network system was proposed. We built a three zones coupled composite model to describe the fracture network. I zone indicates fracture network, which...
Fiber-laden fracture fluid technology has been successfully implemented in unconventional reservoirs for fracture reorientation and fluid leak-off control. Inspired by the encouraging performance achieved in matrix stimulation, a new fiber-added treatment is employed for in-depth profile control, diverting injected fluids into less-permeable zones. The paper is aimed at: 1) highlighting the...
The assessment of the long-term safety of a deep underground repository for radioactive waste requires a comprehensive understanding of the system and appropriate numerical tools. RepoTREND is a final repository simulator being developed by GRS for simulating
- the release of contaminants and
- their transport through the near-field and far-field to the biosphere, including
- the...
The PDEs governing multiphase flow and transport in heterogeneous porous media are highly nonlinear. Therefore, in the fully implicit finite-volume method, solving the algebraic systems is challenging and accounts for most of the simulation cost. We present a numerical scheme applicable to general-purpose simulation that reduces the computational cost by improving the nonlinear convergence....
