title: Transport and retention of Cryptosporidium parvum oocysts in sandy soils.
abstract: A series of miscible-displacement experiments was conducted to examine the retention and transport behavior of  oocysts in natural porous media. Three soils and a model sand were used that differed in physical and geochemical properties. Transport behavior was examined under various treatment conditions to help evaluate retention mechanisms. Significant retention of  oocysts was observed for all media despite the fact that conditions were unfavorable for physicochemical interactions with respect to DLVO theory. The magnitude of  retention was not influenced significantly by alterations in solution chemistry (reduction in ionic strength) or soil surface properties (removal of soil organic matter and metal oxides). On the basis of the observed results, it appears that retention by secondary energy minima or geochemical microdomains was minimal for these systems. The porous media used for the experiments exhibited large magnitudes of surface roughness, and it is suggested that this surface roughness contributed significantly to oocyst retention.
authors: Department of Soil Water and Environmental Science, The University of Arizona, Tucson, AZ, USA.
authors: Johanna
authors: J
authors: Santamaría
authors: Mark L
authors: ML
authors: Brusseau
authors: Juliana
authors: J
authors: Araujo
authors: Patricia
authors: P
authors: Orosz-Coghlan
authors: William J
authors: WJ
authors: Blanford
authors: Charles P
authors: CP
authors: Gerba
mesh_terms: D016785:Cryptosporidium parvum / Q000502:physiology*; D016819:Encephalitozoon / Q000502:physiology; D016829:Giardia lamblia / Q000502:physiology; D033661:Oocysts / Q000502:physiology*; D012822:Silicon Dioxide; D012987:Soil / Q000469:parasitology*
chemical_list: D012987:Soil; D012822:Silicon Dioxide