Institute of Waste Management and Contaminated Site Treatment, Faculty of Forestry, Geosciences and Hydrology, Dresden University of Technology, Germany.
Water Res. 2010 Nov;44(19):5660-72. doi: 10.1016/j.watres.2010.05.053. Epub 2010 Jun 9.
The sorption of the arsenite (AsO(3)(3-)) and the arsenate (AsO(4)(3-)) ions and their conjugate acids onto iron oxides is one of main processes controlling the distribution of arsenic in the environment. The present work intends to provide a large vibrational spectroscopic database for comparison of As(III) and As(V) speciation in aqueous solutions and at the iron oxide - solution interface. With this purpose, ferrihydrite, feroxyhyte, goethite and hematite were firstly synthesized, characterized in detail and used for adsorption experiments. Raman spectra were recorded from As(III) and As(V) aqueous solutions at various pH conditions selected in order to highlight arsenic speciation. Raman Scattering and Diffuse Reflectance Infrared Fourier Transform (DRIFT) studies were carried out to examine the respective As-bonding mechanisms. The collected data were curve-fitted and discussed according to molecular symmetry concepts. X-ray Absorption Near Edge Spectroscopy (XANES) was applied to confirm the oxidation state of the sorbed species. The comprehensive spectroscopic investigation contributes to a better understanding of arsenic complexation by iron oxides.
砷酸盐（AsO(4)(3-）和亚砷酸盐（AsO(3)(3-）离子及其共轭酸在氧化铁上的吸附是控制环境中砷分布的主要过程之一。本工作旨在提供一个大型振动光谱数据库，用于比较水溶液中和氧化铁-溶液界面上的 As(III)和 As(V)形态。为此，首先合成了水铁矿、针铁矿、赤铁矿和磁铁矿，并对其进行了详细的表征，用于吸附实验。记录了不同 pH 值条件下的 As(III)和 As(V)水溶液的拉曼光谱，以突出砷的形态。进行了拉曼散射和漫反射红外傅里叶变换（DRIFT）研究，以检查各自的 As 键合机制。根据分子对称概念对收集的数据进行了曲线拟合和讨论。应用 X 射线吸收近边光谱（XANES）来证实吸附物种的氧化态。综合光谱研究有助于更好地理解铁氧化物对砷的络合。
