Selective Removal of Uranium and Arsenic from Contaminated Groundwater using Silica Polyamine Composites

Graduate #72
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Water

Ranalda L. Tsosie - University of Montana
Co-Author(s): Edward Rosenberg, University of Montana, Missoula, MT

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Using an amino-phosphonic acid ligand bound to the surface of a silica polyamine composite (SPC), we have studied the selective removal of uranyl cation (UO22+) from solutions containing high sulfate (>10,000 ppm) and high nitrate (>1000 ppm) and smaller amounts of other ions. The solutions model the uranium mine waste streams found in wells on the Navajo reservation in Arizona-New Mexico area. Batch capacities, column- breakthrough studies and pH profiles on these solutions will be presented. The hybrid material used BPAP showed excellent capacities and selectivity for uranyl even in the presence of the large excess of anions that are known to form complexes with uranium. The uranyl was recovered from the column experiments by stripping with 2M carbonate solution and giving good mass balances. The results are compared with commercially available polystyrene resins that are reported to be selective for uranium. In addition, these hybrid materials will be tested against actual field samples obtained from contaminated wells.

Funder Acknowledgement(s): EPA STAR Fellowship, EPA Grant Number: FP917795 Alfred P. Sloan SIGP doctoral grant; ISTEM National Science Foundation, Grant Number 1348410; Navajo Nation

Faculty Advisor: Edward Rosenberg, edward.rosenberg@mso.umt.edu

Role: I performed all parts of this study.