The influence of calcium, sodium and bicarbonate on the uptake of uranium onto nanoscale zero-valent iron particles
The influence of calcium, sodium and bicarbonate on the uptake of uranium onto nanoscale zero-valent iron particles
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DOI：
10.1016/j.cej.2015.03.085
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发表时间：
2015-10-01
影响因子：
15.1
通讯作者：
Scott, Thomas B.
中科院分区：
文献类型：
--
作者：
Crane, Richard A.;Pullin, Huw;Scott, Thomas B.
这项工作研究了钙 (Ca)、钠 (Na) 和碳酸氢盐 (HCO(3) over bar) 对纳米级零价铁颗粒 (nZVI) 吸收铀 (U) 的影响。测试溶液中 U 浓度为 1 mg/L，NaHCO3 浓度范围为 0 至 100 mg/L，CaCl2 或 NaCl 浓度范围为 625 至 719 mg/L，以标准化离子强度。矿井水含有相似浓度的 U (1.03 mg/L) 和 HCO(3)，超过 bar 845 mg/L，也作为天然类似物进行了测试。所有溶液均储存在开放实验室的密封玻璃罐中，顶部空间包含环境空气。结果表明，Ca、Na 和 HCO(3) 超过 bar，对 nZVI 从溶液中初始去除 U 的功效没有显着的抑制影响，反应 0.5 小时后，所有研究的系统记录的吸收率 >= 95.7%。在整个 672 小时的实验中，所有不含 Ca 的溶液都记录了类似的 U 保留 (>97.1%)。相比之下，实验后期所有含有 Ca 的溶液均记录了部分 U 解吸，672 小时后，含有 0、10 和 100 mg/L HCO(3) 的溶液分别记录了 87.3%、85.2% 和 84.7% 的去除率，矿井水的去除率分别为 10.9%。对于不含 Ca 的溶液，nZVI 上的最大 U 去除记录为与 HCO(3) 浓度成正比，但对于含 Ca 的溶液，没有发现任何趋势。总体结果表明，Ca 对 U 在 nZVI 上的长期保留（例如 >48 小时）具有显着的抑制影响，当也存在于
This work investigates the influence of calcium (Ca), sodium (Na) and bicarbonate (HCO(3) over bar) on the uptake of uranium (U) onto nanoscale zero-valent iron particles (nZVI). Solutions tested contained U at 1 mg/L, NaHCO3 ranging from 0 to 100 mg/L and CaCl2 or NaCl ranging from 625 to 719 mg/L to normalise the ionic strength. Mine water containing a similar concentration of U (1.03 mg/L) and HCO(3) over bar at 845 mg/L was also tested as a natural analogue. All solutions were stored in sealed glass jars in the open laboratory with headspace comprising ambient air. Results demonstrate Ca, Na and HCO(3) over bar as having no significant inhibitive influence on the efficacy of nZVI for initial U removal from solution, with >= 95.7% uptake recorded for all systems studied after 0.5 h reaction. Similar U retention (>97.1%) was recorded throughout the entire 672 h experiment for all solutions with Ca absent. In contrast, partial U desorption in the latter stages of the experiment was recorded for all solutions with Ca present, with 87.3%, 85.2% and 84.7% removal recorded after 672 h for solutions containing 0, 10 and 100 mg/L HCO(3) over bar, respectively, and 10.9% removal recorded for the mine water. Maximum U removal onto nZVI was recorded as directly proportional to HCO(3) over bar concentration for solutions with Ca absent, however, no trend was identified for the Ca-bearing solutions. Overall results demonstrate Ca as having a significant inhibitive influence on the long-term retention (e.g. >48 h) of U on nZVI, which is independent of HCO(3) over bar concentration when also present at