TY - JOUR
T1 - Transport of Cryptosporidium parvum oocysts in sandy soil
T2 - Impact of length scale
AU - Santamaría, Johanna
AU - Quinonez-Diaz, Maria De J.
AU - Lemond, Luke
AU - Arnold, Robert G.
AU - Quanrud, David
AU - Gerba, Charles
AU - Brusseau, Mark L.
PY - 2011/12
Y1 - 2011/12
N2 - The objective of this study was to investigate the impact of length scale (travel distance) on the retention and transport of Cryptosporidium oocysts in a sandy soil. Long columns (1 and 2 meters) and an in situ lysimeter (4 m) were used to allow investigation of larger-scale transport under controlled conditions. Significant retention of oocysts was observed, with the magnitude of removal from solution ranging between 2 to 5 logs. While the removal was greater for longer travel distances (or residence times), the increase was not log-linear. This observation indicates that oocyst transport was not consistent with standard colloid filtration theory. The observed behavior is speculated to arise, at least in part, from intrapopulation variability in oocyst properties. The results of this study indicate that while Cryptosporidium oocysts may be expected to experience significant retention and removal during transport in sandy soil, the magnitude of retention may be less than that which would be predicted by applying standard colloid filtration theory to the results of typical short-column experiments. Thus, a fraction of the oocysts may be more mobile than anticipated and thereby pose a greater than expected risk to groundwater.
AB - The objective of this study was to investigate the impact of length scale (travel distance) on the retention and transport of Cryptosporidium oocysts in a sandy soil. Long columns (1 and 2 meters) and an in situ lysimeter (4 m) were used to allow investigation of larger-scale transport under controlled conditions. Significant retention of oocysts was observed, with the magnitude of removal from solution ranging between 2 to 5 logs. While the removal was greater for longer travel distances (or residence times), the increase was not log-linear. This observation indicates that oocyst transport was not consistent with standard colloid filtration theory. The observed behavior is speculated to arise, at least in part, from intrapopulation variability in oocyst properties. The results of this study indicate that while Cryptosporidium oocysts may be expected to experience significant retention and removal during transport in sandy soil, the magnitude of retention may be less than that which would be predicted by applying standard colloid filtration theory to the results of typical short-column experiments. Thus, a fraction of the oocysts may be more mobile than anticipated and thereby pose a greater than expected risk to groundwater.
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U2 - 10.1039/c1em10390c
DO - 10.1039/c1em10390c
M3 - Article
C2 - 22027739
AN - SCOPUS:82455167222
SN - 2050-7887
VL - 13
SP - 3481
EP - 3484
JO - Journal of Environmental Monitoring
JF - Journal of Environmental Monitoring
IS - 12
ER -