Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109, United States.
Chemosphere. 2013 Jul;92(4):477-81. doi: 10.1016/j.chemosphere.2013.02.033. Epub 2013 Mar 26.
This work evaluated the inhibitory effect of dissolved silica on arsenite adsorption to nanoparticulate FeS (NP-FeS) or mackinawite and FeS-coated sand (CS-FeS) sorbents. Arsenite retention by the NP-FeS solid was not affected by dissolved silicate over a wide range in pH, in contrast to the known inhibitory effect of dissolved silica on As(III) uptake by Fe-(hydr)oxide systems. However, some inhibition was observed in CS-FeS system at pH 9. This latter result is attributed to the co-existence of both FeS and small amounts of Fe-(hydr)oxide phases on the sand surface. Given the ubiquitous presence of dissolved Si in groundwater, FeS-based sorbents may have an advantage for As retention compared to those based on Fe-(hydr)oxides in reducing subsurface environments.
本研究评估了溶解态硅酸钠对亚砷酸盐在纳米零价铁硫化物（NP-FeS）或胶黄铁矿和硫化铁砂（CS-FeS）上吸附的抑制作用。与溶解态硅酸钠对铁（氢）氧化物体系中亚砷酸盐吸附的抑制作用不同，在很宽的 pH 范围内，溶解态硅酸钠对 NP-FeS 固相中亚砷酸盐的保留没有影响。然而，在 pH 9 时，CS-FeS 体系中观察到了一些抑制作用。这一结果归因于砂表面同时存在 FeS 和少量 Fe（氢）氧化物相。鉴于地下水中普遍存在溶解态硅，与基于铁（氢）氧化物的吸附剂相比，基于 FeS 的吸附剂在还原地下环境中的砷保留方面可能具有优势。
