title: Reactive transport modeling of ⁹⁰Sr sorption in reactive sandpacks.
abstract: Strontium-90 ((90)Sr) is one of the most problematic radioactive contaminants in groundwater at nuclear sites. Although (90)Sr is retarded relative to groundwater flow, it is sufficiently mobile and long-lived to require treatment in many hydrogeological settings. A detailed study was performed on the practicality of using granular clinoptilolite as a sandpack around groundwater wells where groundwater is contaminated with (90)Sr and the water table must be lowered. The effectiveness of the reactive sandpack concept and the mechanisms controlling (90)Sr attenuation was investigated by numerical analysis of data obtained from four in situ column experiments. The experiments spanned the range of pore-water velocities that would occur during radial flow through granular clinoptilolite sandpacks. A kinetic sorption model was required to adequately reproduce the experimentally observed (90)Sr behavior. Calibrated first-order kinetic rates were correlated with pore-water velocities. After calibration, three sorption models were used to simulate (90)Sr attenuation for four hypothetical pumping scenarios. Results show that a velocity-dependent kinetic model accurately simulates the observed early breakthrough for high pore-water velocities. The results indicate (1) that reactive sandpacks have good potential for in situ remediation and construction dewatering and (2) that quantitative modeling can aid in the design and application of this novel technique.
authors.affiliation: Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada; Ministry of Forests, Lands and Natural Resource Operations, Prince George, BC, Canada. Electronic address: jun.yin@gov.bc.ca.
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.affiliation: Department of Earth and Environmental Sciences, Chonbuk National University, Jeonju, Jeollabuk-do 561-756, Republic of Korea; The Earth and Environmental Science System Research Center, Chonbuk National University, Jeonju, Jeollabuk-do 561-756, Republic of Korea.
authors.forename: Sung-Wook
authors.initials: SW
authors.lastname: Jeen
authors.affiliation: Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, Canada.
authors.forename: David R
authors.initials: DR
authors.lastname: Lee
authors.affiliation: Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada.
authors.forename: K Ulrich
authors.initials: KU
authors.lastname: Mayer
mesh_terms: D008956:Models, Chemical; D013324:Strontium / Q000737:chemistry*; D013326:Strontium Radioisotopes / Q000737:chemistry; D014872:Water Movements; D014875:Water Pollutants, Radioactive / Q000737:chemistry*; D014878:Water Pollution, Radioactive / Q000517:prevention & control*
chemical_list: D013326:Strontium Radioisotopes; D014875:Water Pollutants, Radioactive; D013324:Strontium
keywords: Dewatering well; Kinetic sorption; Reactive transport modeling; Strontium-90 ((90)Sr)