磁性水铁矿的制备及其对二甲基亚胂酸的吸附性能

二甲基亚胂酸会对人体和环境造成严重危害。用水热法合成磁性水铁矿，对产物进行了X射线衍射分析、BET比表面积分析和磁滞回线分析，结果表明磁性水铁矿纯度较高，比表面积较大，具有较强的磁性。用磁性水铁矿作为吸附剂，考察了二甲基亚胂酸在磁性水铁矿上的吸附动力学及吸附等温线。二甲基亚胂酸在磁性水铁矿上的吸附符合准二级动力学模型，吸附速率为0.34g·mg^-1·h^-1;吸附等温线符合Freundlich模型。采用Zeta电位测定、FT-IR、SEM-EDS和XPS对吸附机理进行分析，表明磁性水铁矿通过配位络合作用和静电作用来吸附二甲基亚胂酸，在吸附过程中磁性水铁矿表面形了成Fe-O-As三元络合物。研究结果为含有二甲基亚胂酸污染物的水体处理和净化提供了新方法。

Preparation of magnetic ferrihydrite and its adsorption performance on dimethylarsinous acid

Dimethylarsinous acid can cause serious harm to humans and the environment. The magnetic ferrihydrite was synthesized by hydrothermal method, and X-ray diffraction analysis (XRD), BET specific surface area analysis and hysteresis loop analysis were carried out, and the results showed that the magnetic ferrihydrite had higher purity, large specific surface area and strong magnetic properties. The adsorption kinetics and adsorption isotherms of dimethylarsinous acid on magnetic ferrihydrite were investigated by using magnetic ferrihydrite as an adsorbent. The adsorption of dimethylartenous acid on magnetic hydromete conformed to the quasi-secondary kinetic model with an adsorption rate of 0.34 g·mg?1·h?1.The adsorption isotherms conform to the Freundlich model.. Comparing the adsorption isotherms of dimethylarsinous acid on magnetic pyrite at 3, 7 and 11, respectively, the adsorption amount of dimethylarsinous acid was the largest at neutral time, reaching 11.2 mg/g; The adsorption is small under acidic and alkaline conditions. The adsorption mechanism was analyzed by Zeta potential determination, FT-IR scanning electron microscopy SEM-EDS and X-ray photoelectron spectroscopy XPS, and it was shown that magnetic ferrihydrite adsorbed Dimethylarsinous acid through coordination networking and electrostatic action, and fe-O-As ternary complexes were formed on the surface of magnetic ferrihydrite during adsorption. New methods are provided for the treatment and purification of water bodies containing dimethylarsinous acid contaminants.