title: Temperature dependency of virus and nanoparticle transport and retention in saturated porous media.
abstract: The influence of temperature on virus (PRD1 and ΦX174) and carboxyl-modified latex nanoparticle (50 and 100nm) attachment was examined in sand-packed columns under various physiochemical conditions. When the solution ionic strength (IS) equaled 10 and 30mM, the attachment rate coefficient (katt) increased up to 109% (p<0.0002) and the percentage of the sand surface area that contributed to attachment (Sf) increased up to 160% (p<0.002) when the temperature was increased from 4 to 20°C. Temperature effects at IS=10 and 30mM were also dependent on the system hydrodynamics; i.e., enhanced retention at a lower pore water velocity (0.1m/day). Conversely, this same temperature increase had a negligible influence on kattand Sfvalues when IS was 1mM or >50mM. An explanation for these observations was obtained from extended interaction energy calculations that considered nanoscale roughness and chemical heterogeneity on the sand surface. Interaction energy calculations demonstrated that the energy barrier to attachment in the primary minimum (∆Φa) decreased with increasing IS, chemical heterogeneity, and temperature, especially in the presence of small amounts of nanoscale roughness (e.g., roughness fraction of 0.05 and height of 20nm in the zone of influence). Temperature had a negligible effect on kattand Sfwhen the IS=1mM because of the large energy barrier, and at IS=50mM because of the absence of an energy barrier. Conversely, temperature had a large influence on kattand Sfwhen the IS was 10 and 30mM because of the presence of a small ∆Φaon sand with nanoscale roughness and a chemical (positive zeta potential) heterogeneity. This has large implications for setting parameters for the accurate modeling and transport prediction of virus and nanoparticle contaminants in ground water systems.
authors.affiliation: CSIRO Land and Water, Glen Osmond, SA 5064, Australia; National Centre for Groundwater Research and Training, Adelaide, SA 5001, Australia; Flinders University, Bedford Park, Adelaide, SA 5042, Australia. Electronic address: salini.sasidharan@flinders.edu.au.
authors.forename: Salini
authors.initials: S
authors.lastname: Sasidharan
authors.affiliation: CSIRO Land and Water, Glen Osmond, SA 5064, Australia.
authors.forename: Saeed
authors.initials: S
authors.lastname: Torkzaban
authors.affiliation: USDA, ARS, Salinity Laboratory, Riverside, CA 92507, United States.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Bradford
authors.affiliation: National Centre for Groundwater Research and Training, Adelaide, SA 5001, Australia; Flinders University, Bedford Park, Adelaide, SA 5042, Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Cook
authors.affiliation: CSIRO Agriculture, Glen Osmond, SA 5064, Australia.
authors.forename: Vadakattu V S R
authors.initials: VVSR
authors.lastname: Gupta
mesh_terms: D025622:Bacteriophage PRD1 / Q000737:chemistry; D010584:Bacteriophage phi X 174 / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry / Q000821:virology; D008962:Models, Theoretical; D053758:Nanoparticles / Q000032:analysis*; D009994:Osmolar Concentration; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry; D012996:Solutions; D013499:Surface Properties; D013696:Temperature; D014871:Water Microbiology; D014872:Water Movements
chemical_list: D012996:Solutions; D012822:Silicon Dioxide
keywords: Nanoparticle; Retention; Surface roughness; Temperature; Virus; XDLVO theory