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Title: Transport of Cryptosporidium parvum Oocysts in a Silicon Micromodel

Effective removal of Cryptosporidium parvum oocysts by granular filtration requires the knowledge of oocyst transport and deposition mechanisms, which can be obtained based on real time microscopic observation of oocyst transport in porous media. Attachment of oocysts to silica surface in a radial stagnation point flow (RSPF) cell and in a micromodel, which has 2-dimensional (2-D) microscopic pore structures consisting of an array of cylindrical collectors, was studied and compared. Real time transport of oocysts in the micromodel was recorded to determine the attached oocyst distributions in transversal and longitudinal directions. In the micromodel, oocysts attached to the forward portion of clean collectors, where the flow velocity was lowest. After initial attachment, oocysts attached onto already attached oocysts. As a result, the collectors ripened and the region available for flow was reduced. Results of attachment and detachment experiments suggest that surface charge heterogeneity allowed for oocyst attachment. In addition to experiments, Lattice-Boltzmann simulations helped understanding the slightly non-uniform flow field and explained differences in the removal efficiency in the transversal direction. However, the hydrodynamic modeling could not explain differences in attachment in the longitudinal direction.
Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
1034969
Report Number(s):
PNNL-SA-85008
Journal ID: ISSN 0013-936X; ESTHAG; 44692; 38491; KP1704020; TRN: US201204%%262
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Science and Technology; Journal Volume: 46; Journal Issue: 3
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; DEPOSITION; EFFICIENCY; FILTRATION; HYDRODYNAMICS; PORE STRUCTURE; REMOVAL; SILICA; SILICON; SIMULATION; STAGNATION POINT; TRANSPORT; VELOCITY colloid transport, micromodel, Lattice-Boltzmann Model; Environmental Molecular Sciences Laboratory