Radioactive colloid advection in a sorbing porous medium: Analytical solution
Colloids are capable of increasing rates of hydrogeologic transport because they can move faster on average than solute due to hydrodynamic chromotography, they can be retarded less than solute by sorption onto rock, and they can increase the apparent liquid-phase radionuclide concentration. Colloid formation might occur as water carrying radionuclide solute leaves the immediate vicinity of the waste package and encounters changing geochemical conditions. Also, colloids of less soluble waste species might form as the waste matrix around them dissolves and migrates away. We restrict our analysis to true colloids'' that are a solid-phase of the radionuclide itself. To predict one-dimensional transport of colloids through a sorbing porous medium with coupling to the solute phase, we assume a concentration step function in time at the inlet boundary. We neglect dispersion and assume local sorption equilibrium with distinct retardation coefficients for the colloid and solute phases. We also assume local equilibrium between colloid and solute phase concentrations, resulting in solute concentration of the colloid solubility limit whenever the colloid phase is present. Colloid filtration is neglected. We expect the colloid front to travel faster than that of the solute as result of disparities in retardation. The solution involves mathematical difficulties. The analytical solution described in this paper provides unique insight to the fundamental behavior of a colloid system. 1 fig.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- DOE/RW
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6710979
- Report Number(s):
- LBL-28426; CONF-900608-50; ON: DE90015305
- Resource Relation:
- Conference: American Nuclear Society annual meeting, Nashville, TN (USA), 10-14 Jun 1990
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COLLOIDS
ADVECTION
RADIOACTIVE MATERIALS
RADIONUCLIDE MIGRATION
ANALYTICAL SOLUTION
ENVIRONMENTAL TRANSPORT
MATHEMATICAL MODELS
POROUS MATERIALS
SORPTION
SORPTIVE PROPERTIES
DISPERSIONS
MASS TRANSFER
MATERIALS
SURFACE PROPERTIES
540230* - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- (1990-)