Journal ArticleDOI
Transport of Cryptosporidium Oocysts in Porous Media: Role of Straining and Physicochemical Filtration
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TLDR
The results of this study indicate that irregularity of sand grain shape contributes considerably to the straining potential of the porous medium, and both straining and physicochemical filtration are expected to control the removal of C. parvum oocysts in settings typical of riverbank filTration, soil infiltration, and slow sand filtrations.Abstract:
The transport and filtration behavior of Cryptosporidium parvum oocysts in columns packed with quartz sand was systematically examined under repulsive electrostatic conditions. An increase in solution ionic strength resulted in greater oocyst deposition rates despite theoretical predictions of a significant electrostatic energy barrier to deposition. Relatively high deposition rates obtained with both oocysts and polystyrene latex particles of comparable size at low ionic strength (1 mM) suggest that a physical mechanism may play a key role in oocyst removal. Supporting experiments conducted with latex particles of varying sizes, under very low ionic strength conditions where physicochemical filtration is negligible, clearly indicated that physical straining is an important capture mechanism. The results of this study indicate that irregularity of sand grain shape (verified by SEM imaging) contributes considerably to the straining potential of the porous medium. Hence, both straining and physicochemical filtration are expected to control the removal of C. parvum oocysts in settings typical of riverbank filtration, soil infiltration, and slow sand filtration. Because classic colloid filtration theory does not account for removal by straining, these observations have important implications with respect to predictions of oocyst transport.read more
Citations
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Straining of polyelectrolyte-stabilized nanoscale zero valent iron particles during transport through granular porous media.
TL;DR: It is demonstrated that CMC-NZVI particles, despite of their small size, may be removed by straining during transport, especially through fine granular subsurface media, as well as in porous media due to straining and/or wedging.
Journal ArticleDOI
Deposition and re-entrainment dynamics of microbes and non-biological colloids during non-perturbed transport in porous media in the presence of an energy barrier to deposition
TL;DR: In this paper, the authors examined the non-perturbed deposition and re-entrainment dynamics of biological and non-biological colloids in porous media in the presence of an energy barrier to deposition at the grain surface.
Journal ArticleDOI
Transport of two metal oxide nanoparticles in saturated granular porous media: Role of water chemistry and particle coating
TL;DR: The finding that bare (uncoated) nanoparticles exhibit high retention within the water saturated granular matrix at solution ionic strengths (IS) as low as 0.1 mM NaNO3 illustrates the importance of considering the extent and type of surface modification when evaluating metal oxide contamination potential in granular aquatic environments.
Journal ArticleDOI
Straining of nonspherical colloids in saturated porous media.
TL;DR: Findings from this research suggest that straining is sensitive to changes in colloid shape and that the kinetics of this process can be approximated on the basis of measurable properties of the nonspherical colloids and porous media.
Journal ArticleDOI
Kinetic adhesion of bacterial cells to sand: Cell surface properties and adhesion rate
TL;DR: The results obtained with a large variety of different physicochemical bacterial strains highlights the influence of both surface thermodynamics and porous media related effects as well as the limits of using the XDLVO theory for evaluating bacterial retention through porous media.
References
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Book
Foundations of Colloid Science
TL;DR: The structure of concentrated dispersions thin films Emulsions Microemulsions Rheology of colloidal dispersions and their properties are described in detail in this paper, with a focus on statistical mechanics of fluids.
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Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes
B.V. Derjaguin,L Landau +1 more
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Mutual coagulation of colloidal dispersions
TL;DR: In this paper, a quantitative theory is presented which describes the kinetics of coagulation of colloidal systems containing more than one dispersed species, using the linear (Debye-Huckel) approximation for low surface potentials.