Key Laboratory of Bio-geology and Environmental Geology of Ministry of Education, China University of Geosciences, Wuhan, Hubei 430074, China.
Environ Sci Technol. 2010 Oct 15;44(20):7783-9. doi: 10.1021/es9036308.
This study investigated the influences of pH, bicarbonate, and calcium on U(VI) removal and reduction by synthetic nanoscale zerovalent iron (nanoFe(0)) particles under anoxic conditions. The results showed that the rates of U(VI) removal and reduction by nanoFe(0) varied significantly with pH and concentrations of bicarbonate and/or calcium. For instance, at pH 6.92 the pseudo-first-order rate constants of U(VI) removal decreased by 78.5% and 81.3%, and U(VI) reduction decreased by 90.3% and 89.3%, when bicarbonate and calcium concentrations were increased from 0 to 1 mM, respectively. X-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of UO(2) and iron (hydr)oxides as a result of the redox interactions between U(VI) and nanoFe(0). The study demonstrated the potential of using nanoFe(0) for U(VI)-contaminated site remediation and highlighted the impacts of pH, bicarbonate, and calcium on the U(VI) removal and reduction processes.
本研究考察了在缺氧条件下，pH 值、碳酸氢根和钙离子对合成纳米零价铁（nanoFe(0)）颗粒去除和还原 U(VI)的影响。结果表明，nanoFe(0)去除和还原 U(VI)的速率随 pH 值以及碳酸氢根和/或钙离子浓度的变化而显著变化。例如，在 pH 值为 6.92 时，当碳酸氢根和钙离子浓度分别从 0 增加到 1 mM 时，U(VI)去除的拟一级速率常数降低了 78.5%和 81.3%，U(VI)还原降低了 90.3%和 89.3%。X 射线光电子能谱（XPS）分析证实了 U(VI)与 nanoFe(0)之间的氧化还原相互作用导致了 UO(2)和铁（氢）氧化物的形成。该研究表明了使用 nanoFe(0)修复 U(VI)污染场地的潜力，并强调了 pH 值、碳酸氢根和钙离子对 U(VI)去除和还原过程的影响。
