A practical approach for in-situ hydrous ferric oxide (HFO) precipitation was developed for iodine immobilization under field-scale conditions at the Hanford Site. A series of 1D meter-long bench top column experiments packed with Hanford sediments was conducted with a single acidic ferric solution (0.1 M, pH = 1.5) injection. Because carbonate and clay minerals are widely present in sediments, self-pH buffering of the injected acidic ferric solution occurred due to mineral dissolution, leading to HFO precipitation under a neutral condition. Up to ~12 mg/g HFO successfully precipitated and evenly distributed in the column sediments, and the remobilization of the neo-formed HFO precipitates was limited (
Revised: December 21, 2020 |
Published: November 2, 2020
Citation
Wang G., J.E. Szecsody, N.M. Avalos, N. Qafoku, and V.L. Freedman. 2020.In situ precipitation of hydrous ferric oxide (HFO) for remediation of subsurface iodine contamination.Journal of Contaminant Hydrology 235.PNNL-SA-147880.doi:10.1016/j.jconhyd.2020.103705