School of Ecological and Environmental Science, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai, China.
Department of Chemistry and Chemical Engineering, Heze University, Heze, China.
Chemosphere. 2017 Aug;181:328-336. doi: 10.1016/j.chemosphere.2017.04.049. Epub 2017 Apr 18.
Arsenic pollution poses severe threat to human health, therefore dealing with the problem of arsenic contamination in water bodies is extremely important. The adsorption behaviors of different arsenic species, such as arsenate (As(V)), p-arsanilic acid (p-ASA), roxarsone (ROX), dimethylarsenate (DMA) from water using mesoporous bimetal oxide magnetic manganese ferrite nanoparticles (MnFeO) have been detailedly investigated. The adsorbent was synthesized via a facile co-precipitation approach and recovered conveniently owing to its strong magnetic properties. The obtained MnFeO with large surface area and abundant hydroxyly functional groups exhibited excellent adsorption performance for As(V) and p-ASA, in contrast to ROX and DMA with the maximum adsorption capacities of As(V), p-ASA, ROX and DMA of 68.25 mg g, 59.45 mg g, 51.49 mg g, and 35.77 mg g, respectively. The Langmuir model and the pseudo-second-order kinetic model correlated satisfactorily with the adsorption thermodynamics and kinetics, and thermodynamic parameters depicted the spontaneous endothermic nature for the adsorption of different arsenic species. The adsorption mechanism of different arsenic species onto MnFeO nanoparticles at various pH values could be explained by surface complexation and molecular structural variations. Attenuated Total internal Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) further proved that arsenic species were bonded to the surface of MnFeO through the formation of an inner-sphere complex between the arsenic acid moiety and surface metal centers. The results would help to know the interaction of arsenic species with iron-manganese minerals and the mobility of arsenic species in natural environments.
砷污染对人类健康构成严重威胁，因此处理水体中砷污染问题至关重要。本文详细研究了不同砷物种（如砷酸盐（As(V)）、对氨基苯砷酸（p-ASA）、洛克沙胂（ROX）、二甲砷酸（DMA））在水中用介孔双金属氧化物磁性锰铁氧化物纳米粒子（MnFeO）的吸附行为。该吸附剂是通过简便的共沉淀法合成的，并由于其强磁性而方便地回收。所得的 MnFeO 具有较大的表面积和丰富的羟基数官能团，对 As(V)和 p-ASA 表现出优异的吸附性能，而对 ROX 和 DMA 的最大吸附容量分别为 68.25 mg g、59.45 mg g、51.49 mg g 和 35.77 mg g。Langmuir 模型和准二级动力学模型与吸附热力学和动力学很好地相关，热力学参数表明了不同砷物种吸附的自发吸热性质。在不同 pH 值下，不同砷物种在 MnFeO 纳米粒子上的吸附机制可以通过表面络合和分子结构变化来解释。衰减全反射傅里叶变换红外光谱（ATR-FTIR）和 X 射线光电子能谱（XPS）进一步证明了砷物种通过砷酸部分与表面金属中心之间形成内球络合物与 MnFeO 表面结合。这些结果有助于了解砷物种与铁锰矿物的相互作用以及砷物种在自然环境中的迁移性。
