Department of Natural Resources and Environmental Engineering, Hanyang University, Seongdong-gu, Seoul, South Korea.
Environ Geochem Health. 2011 Jan;33 Suppl 1:13-22. doi: 10.1007/s10653-010-9360-4. Epub 2010 Nov 3.
Subsurface geochemical behavior of As(V) with Fe(II) was studied under strict anoxic conditions. Abiotic reduction of As(V) (0.1 mM) to As(III) by aqueous Fe(II) and sorbed Fe(II) in pH range 5.0-7.0 and Fe(II)(aq) concentration (0.6-1.2 mM) was investigated along with the effect of As(V) on the oxidation of Fe(II) by dissolved oxygen (DO). Although the reduction was thermodynamically feasible for homogeneous chemical conditions, practically no As(V) reduction by aqueous Fe(II) was observed. Similarly, no sorbed As(V) reduction was observed under the heterogeneous experimental conditions by sorbed Fe(II) onto synthetic iron oxide (hematite, α-Fe₂O₃). Experimental results on Fe(II) oxidation by DO in the presence of 0.1 mM As(V) showed a significantly slower Fe(II) oxidation, which might be due to the formation of Fe(II)-As(V) complex in the aqueous phase. The results of this study demonstrate that As(V) is relatively stable in the presence of Fe(II) under subsurface environment and interfere the oxidation of Fe(II).
在严格的缺氧条件下研究了 As(V)与 Fe(II)的地下地球化学行为。研究了在 pH 值为 5.0-7.0 和 Fe(II)(aq)浓度（0.6-1.2 mM）范围内，水合 Fe(II)和吸附态 Fe(II)将 As(V)（0.1 mM）还原为 As(III)，以及 As(V)对溶解氧（DO）氧化 Fe(II)的影响。尽管从热力学上看，均相化学条件下的还原是可行的，但实际上并没有观察到水合 Fe(II)对 As(V)的还原。同样，在吸附态 Fe(II)吸附到合成氧化铁（赤铁矿，α-Fe₂O₃）的非均相实验条件下，也没有观察到吸附态 As(V)的还原。在存在 0.1 mM As(V)的情况下，DO 氧化 Fe(II)的实验结果表明，Fe(II)的氧化明显变慢，这可能是由于在水相中形成了 Fe(II)-As(V)配合物。本研究结果表明，在地下环境中存在 Fe(II)时，As(V)相对稳定，并干扰了 Fe(II)的氧化。
