In recent decades, the use of natural and modified
sorbents has been considered for in situ remediation of uranium mining/milling
waste sites. Natural (bentonite and aluminosilicates) and modified clays
(montmorillonite and other organo-clays) have been used to remove mobility
of radioactive materials. Stabilization of uranium mining/milling waste
sites using natural and modified clays may prevent transport of uranium
waste and subsequently reduce "bioavailability" of uranium to biosorption,
plant uptake, earthworms, and microorganisms. In this proposed research,
the remediation potential of natural and organo-clays in immobilization
of uranium mining wastes will be investigated. Sorption and desorption
characteristics are the main controlling factors determining the applicability
of these sorbents in the immobilization of used fuel wastes. Researches
dealing with interaction of the residual metals with soil should be conducted
for better treatment or remediation of radioactive wastes.
The projects will focus on characterization of the sorption of uranium
species on natural and organically modified clays. Sorption/desorption
experiments will be conducted to investigate sorption/desorption characteristics
of the sorbents. Generated sorption data will be calibrated using various
sorption models. Laboratory studies will be continued to determine the
immobilization capacity of the sorbents for the treatment of uranium mining
wastes. The effect of the addition of illitic materials on will be investigated.
A Fortran driver program will be written to model the fate and transport
of metals using a one dimensional advective dispersive transport code (CXTFIT).
The determined nonlinear sorption model will be incorporated into the CXTFIT
program to simulate transport of labile metal ions in the water. Ability
and economic feasibility of the clays for in situ treatment of the radioactive
wastes will be analyzed based on the experimental and numerical modeling
results. |
Korea