Abstract
We present theoretical and experimental work on Cryptosporidium parvum oocysts to characterize their transport behavior in saturated, sandy sediments under strictly controlled conditions. Column experiments are implemented with three different sands (effective grain size: 180, 420, and 1400 μm) at two different saturated flow rates (0.7 and 7 m/d). The experiments show that C. parvum oocysts, like other colloids, are subject to velocity enhancement. In medium and coarse sands, the oocysts travel 10-30% faster than a conservative tracer. The classic clean-bed filtration model is found to provide an excellent tool to estimate the degree of C. parvum filtration. Experimentally determined collision efficiencies, α, range from 0.4 to 1.1. The magnitude of α is consistent with the known physical and chemical properties of the oocyst and the transport medium and compares well with, e.g., measured collision efficiencies of similarly sized E. coli bacteria. However, a significant amount of the initial deposition appears to be reversible leading to significant asymmetry and tailing in the oocyst concentration breakthrough curve. We are able to show that the observed late-time oocyst elution can qualitatively be explained by postulating that a significant fraction of the oocyst filtration is reversible and subject to time-dependent detachment.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 62-70 |
| Number of pages | 9 |
| Journal | Environmental Science and Technology |
| Volume | 34 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2000 |
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ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Environmental Engineering
Cite this
Colloid transport and filtration of Cryptosporidium parvum in sandy soils and aquifer sediments. / Harter, Thomas; Wagner, Sonja; Atwill, Edward R.
In: Environmental Science and Technology, Vol. 34, No. 1, 01.01.2000, p. 62-70.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Colloid transport and filtration of Cryptosporidium parvum in sandy soils and aquifer sediments
AU - Harter, Thomas
AU - Wagner, Sonja
AU - Atwill, Edward R
PY - 2000/1/1
Y1 - 2000/1/1
N2 - We present theoretical and experimental work on Cryptosporidium parvum oocysts to characterize their transport behavior in saturated, sandy sediments under strictly controlled conditions. Column experiments are implemented with three different sands (effective grain size: 180, 420, and 1400 μm) at two different saturated flow rates (0.7 and 7 m/d). The experiments show that C. parvum oocysts, like other colloids, are subject to velocity enhancement. In medium and coarse sands, the oocysts travel 10-30% faster than a conservative tracer. The classic clean-bed filtration model is found to provide an excellent tool to estimate the degree of C. parvum filtration. Experimentally determined collision efficiencies, α, range from 0.4 to 1.1. The magnitude of α is consistent with the known physical and chemical properties of the oocyst and the transport medium and compares well with, e.g., measured collision efficiencies of similarly sized E. coli bacteria. However, a significant amount of the initial deposition appears to be reversible leading to significant asymmetry and tailing in the oocyst concentration breakthrough curve. We are able to show that the observed late-time oocyst elution can qualitatively be explained by postulating that a significant fraction of the oocyst filtration is reversible and subject to time-dependent detachment.
AB - We present theoretical and experimental work on Cryptosporidium parvum oocysts to characterize their transport behavior in saturated, sandy sediments under strictly controlled conditions. Column experiments are implemented with three different sands (effective grain size: 180, 420, and 1400 μm) at two different saturated flow rates (0.7 and 7 m/d). The experiments show that C. parvum oocysts, like other colloids, are subject to velocity enhancement. In medium and coarse sands, the oocysts travel 10-30% faster than a conservative tracer. The classic clean-bed filtration model is found to provide an excellent tool to estimate the degree of C. parvum filtration. Experimentally determined collision efficiencies, α, range from 0.4 to 1.1. The magnitude of α is consistent with the known physical and chemical properties of the oocyst and the transport medium and compares well with, e.g., measured collision efficiencies of similarly sized E. coli bacteria. However, a significant amount of the initial deposition appears to be reversible leading to significant asymmetry and tailing in the oocyst concentration breakthrough curve. We are able to show that the observed late-time oocyst elution can qualitatively be explained by postulating that a significant fraction of the oocyst filtration is reversible and subject to time-dependent detachment.
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U2 - 10.1021/es990132w
DO - 10.1021/es990132w
M3 - Article
AN - SCOPUS:0033986284
VL - 34
SP - 62
EP - 70
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 1
ER -