scholarly journals Effect of Clay Colloid Particles on Formaldehyde Transport in Unsaturated Porous Media

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3541
Author(s):  
Theodosia V. Fountouli ◽  
Constantinos V. Chrysikopoulos
Keyword(s):  
Porous Media ◽  
Quartz Sand ◽  
Experimental Results ◽  
Low Flow ◽  
Unsaturated Porous Media ◽  
Flow Rates ◽  
Clay Particles ◽  
Colloid Retention ◽  
Clay Colloid

This study examines the effects of two representative colloid-sized clay particles (kaolinite, KGa-1b and montmorillonite, STx-1b) on the transport of formaldehyde (FA) in unsaturated porous media. The transport of FA was examined with and without the presence of clay particles under various flow rates and various levels of saturation in columns packed with quartz sand, under unsaturated conditions. The experimental results clearly suggested that the presence of clay particles retarded by up to ~23% the transport of FA in unsaturated packed columns. Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction energy calculations demonstrated that permanent retention of clay colloids at air-water interfaces (AWI) and solid-water interfaces (SWI) was negligible, except for the pair (STx-1b)–SWI. The experimental results of this study showed that significant clay colloid retention occurred in the unsaturated column, especially at low flow rates. This deviation from DLVO predictions may be explained by the existence of additional non-DLVO forces (hydrophobic and capillary forces) that could be much stronger than van der Waals and double layer forces. The present study shows the important role of colloids, which may act as carriers of contaminants.

Transport of formaldehyde in water unsaturated laboratory columns packed with quartz sand: Effect of colloid-sized clay particles.

2020 ◽  
Author(s):  
Theodosia V. Fountouli ◽  
Constantinos V. Chrysikopoulos
Keyword(s):  
Vadose Zone ◽  
Quartz Sand ◽  
Water Saturation ◽  
Packed Column ◽  
Interaction Energies ◽  
Unsaturated Porous Media ◽  
Great Abundance ◽  
Clay Particles ◽  
Colloid Particles ◽  
Colloid Retention

<p>Colloid-sized clay particles are in great abundance in the unsaturated or vadose zone and are capable of binding a variety of contaminants, which in turn either facilitate or hinder their migration in the subsurface. Also, FA has relatively strong affinity for kaolinite colloid particles (Fountouli et al., 2019). This study examines the effects of two representative colloid-sized clay particles (kaolinite, montmorillonite) on the transport of formaldehyde (FA) in unsaturated porous media. Transport experiments were performed in columns packed with quartz sand, under unsaturated conditions. The transport of FA was examined with and without the presence of suspended clay particles under various flow rates and various levels of saturation. DLVO interaction energies and the capillary potential energy associated with colloid retention at air-water and solid-water interfaces were calculated. The experimental results clearly suggested that the presence of suspended clay particles hindered the transport of FA in unsaturated packed columns. Moreover, as expected, it was shown that clay particle retention in the packed column increased with decreasing level of water saturation.</p><p> </p><p>Reference</p><p>Fountouli, T.V., C.V. Chrysikopoulos, and I.K. Tsanis, Effect of salinity on formaldehyde interaction with quartz sand and kaolinite colloid particles: batch and column experiments. Environmental Earth Sciences 78, 152, 2019.</p><p> </p>

Colloid Retention in Unsaturated Porous Media as Impacted by Colloid Size

2009 ◽  
Vol 27 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Gang Chen ◽  
Junliang Liu ◽  
Kamal Tawfiq ◽  
Kai Yang ◽  
Christal Banks
Keyword(s):  
Porous Media ◽  
Unsaturated Porous Media ◽  
Colloid Retention

scholarly journals Influence of mineralization and injection flow rate on flow patterns in three-dimensional porous media

2019 ◽  
Vol 21 (27) ◽  
pp. 14605-14611 ◽  
Author(s):  
R. Moosavi ◽  
A. Kumar ◽  
A. De Wit ◽  
M. Schröter
Keyword(s):  
Porous Media ◽  
Flow Field ◽  
Flow Rate ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Low Flow ◽  
Flow Rates ◽  
Injection Flow Rate ◽  
Injection Flow

At low flow rates, the precipitate forming at the miscible interface between two reactive solutions guides the evolution of the flow field.

NMR velocimetry with 13-interval stimulated echo multi-slice imaging in natural porous media under low flow rates

2011 ◽  
Vol 212 (1) ◽  
pp. 216-223 ◽  
Author(s):  
Natascha Spindler ◽  
Petrik Galvosas ◽  
Andreas Pohlmeier ◽  
Harry Vereecken
Keyword(s):  
Porous Media ◽  
Low Flow ◽  
Flow Rates ◽  
Stimulated Echo ◽  
Slice Imaging

Regulation of cation transport in the distal nephron by mechanical forces

2006 ◽  
Vol 291 (5) ◽  
pp. F923-F931 ◽  
Author(s):  
Lisa M. Satlin ◽  
Marcelo D. Carattino ◽  
Wen Liu ◽  
Thomas R. Kleyman
Keyword(s):  
Apical Membrane ◽  
Low Flow ◽  
Urinary Flow ◽  
Distal Nephron ◽  
Cellular Mechanisms ◽  
Flow Rates ◽  
Resultant Increase ◽  
Tubular Flow ◽  
Biomechanical Forces

Thiazide and loop diuretics induce renal K+ secretion, often leading to renal K+ wasting and hypokalemia. This phenomenon has been proposed to reflect an increase in delivery to and reabsorption of Na+ by the distal nephron, with a resultant increase in the driving force for passive K+ efflux across the apical membrane. Recent studies suggest that cellular mechanisms that lead to enhanced rates of Na+ reabsorption as well as K+ secretion in response to increases tubular flow rates are more complex. Increases in tubular flow rates directly enhance the activity of apical membrane Na+ channels and indirectly activate a class of K+ channels, referred to as maxi-K, that are functionally inactive under low flow states. This review addresses the role of biomechanical forces, generated by variations in urinary flow rate and tubular fluid volume, in the regulation of transepithelial Na+ and K+ transport in the distal nephron. The question of why the distal nephron has evolved to include a component of flow-dependent K+ secretion is also addressed.

The Effects of Sublimation-Condensation Region on Heat and Mass Transfer During Microwave Freeze Drying

1998 ◽  
Vol 120 (3) ◽  
pp. 654-660 ◽  
Author(s):  
Zhao Hui Wang ◽  
Ming Heng Shi
Keyword(s):  
Mass Transfer ◽  
Porous Media ◽  
Heat And Mass Transfer ◽  
Freeze Drying ◽  
Experimental Results ◽  
Interface Model ◽  
Unsaturated Porous Media ◽  
Drying Time ◽  
Condensation Model ◽  
Moisture Redistribution

The sublimation-condensation model, developed for freeze drying of unsaturated porous media in the author’s previous work, is analyzed numerically. The moisture redistribution in the sublimation-condensation region is taken into account in this model. The calculations show that the saturation of ice in the sublimation-condensation region will obviously decrease, and its effects on heat and mass transfer cannot be neglected for microwave freeze-drying of unsaturated porous media. The microwave freeze-drying tests of unsaturated beef are carried out. The experimental results show that the drying time is approximately proportional to the initial saturation of beef. Moreover the sublimation-condensation model is validated by the experimental results. These results show that the sublimation-condensation model agrees better with experimental results than the sublimation interface model.

scholarly journals Polymer Injectivity: Investigation of Mechanical Degradation of Enhanced Oil Recovery Polymers Using In-Situ Rheology

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 49 ◽  
Author(s):  
Badar Al-Shakry ◽  
Tormod Skauge ◽  
Behruz Shaker Shiran ◽  
Arne Skauge
Keyword(s):  
Porous Media ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Shear Thickening ◽  
Water Soluble ◽  
High Rate ◽  
Low Flow ◽  
Mechanical Degradation ◽  
Flow Rates

Water soluble polymers have attracted increasing interest in enhanced oil recovery (EOR) processes, especially polymer flooding. Despite the fact that the flow of polymer in porous medium has been a research subject for many decades with numerous publications, there are still some research areas that need progress. The prediction of polymer injectivity remains elusive. Polymers with similar shear viscosity might have different in-situ rheological behaviors and may be exposed to different degrees of mechanical degradation. Hence, determining polymer in-situ rheological behavior is of great significance for defining its utility. In this study, an investigation of rheological properties and mechanical degradation of different partially hydrolyzed polyacrylamide (HPAM) polymers was performed using Bentheimer sandstone outcrop cores. The results show that HPAM in-situ rheology is different from bulk rheology measured by a rheometer. Specifically, shear thickening behavior occurs at high rates, and near-Newtonian behavior is measured at low rates in porous media. This deviates strongly from the rheometer measurements. Polymer molecular weight and concentration influence its viscoelasticity and subsequently its flow characteristics in porous media. Exposure to mechanical degradation by flow at high rate through porous media leads to significant reduction in shear thickening and thereby improved injectivity. More importantly, the degraded polymer maintained in-situ viscosity at low flow rates indicating that improved injectivity can be achieved without compromising viscosity at reservoir flow rates. This is explained by a reduction in viscoelasticity. Mechanical degradation also leads to reduced residual resistance factor (RRF), especially for high polymer concentrations. For some of the polymer injections, successive degradation (increased degradation with transport length in porous media) was observed. The results presented here may be used to optimize polymer injectivity.

Sign in / Sign up

Export Citation Format

Share Document