Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

Szecsody, James E. ; Vermeul, Vincent R. ; Fruchter, Jonathan S. ; Williams, Mark D. ; Rockhold, Mark L. ; Qafoku, Nikolla ; Phillips, Jerry L.

Pacific Northwest National Laboratory (PNNL), Richland, WA (United States), Environmental Molecular Sciences Laboratory (EMSL)

关键词: Strontium-90, Groundwater Remediation, Apatite;    Sodium;    Sediments;    Sodium Phosphates;    Positioning;   

DOI  :  10.2172/985586
RP-ID  :  PNNL-19524
RP-ID  :  AC05-76RL01830
RP-ID  :  985586

美国|英语

来源: UNT Digital Library

【 摘 要 】

The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.