羧酸配位前驱体法制备铁镍复合氧化物及其对Cr(Ⅵ)的吸附性能

Preparation of Iron-nickel Composite Oxides by Carboxylate Coordination Precursor Method and Their Adsorption Property of Cr(Ⅵ)

采用不同二元羧酸(草酸、丙二酸、丁二酸和酒石酸)为配位沉淀剂,通过羧酸配位前驱体法制备出铁镍复合氧化物,采用场发射扫描电镜、X射线粉末衍射仪、Fourier红外光谱分析仪等对产物的形貌及物相进行了表征,探讨了二元羧酸分子结构对铁镍复合氧化物物相形成的影响,考察了样品用于含Cr(Ⅵ)模拟废水处理时的性能。结果表明:以不同二元羧酸沉淀剂制备出的铁镍复合氧化物的物相不同,其对水体中的Cr(Ⅵ)吸附性能也不同,其中以酒石酸配位前驱体获得的铁镍复合氧化物Cr(Ⅵ)去除效果最好。在pH=2.0时,吸附剂的吸附效果最佳。吸附过程符合动力学第二方程。

Iron-nickel composite oxides were prepared with oxalic acid, malonic acid, succinic acid and tartaric acid by a carboxylate coordination precursor method. These composite oxides were characterized by field emission scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The phase formation of iron-nickel composite oxides was affected by the molecular structure of dicarboxylic acids. The adsorption property of Cr（Ⅵ） onto iron-nickel composite oxides was investigated. The results show that the phase of as-prepared iron-nickel composite oxides prepared with different dicarboxylic acids as a precipitator is different, giving the various adsorption properties of Cr（Ⅵ）. The iron-nickel composite oxides prepared with tartrate precursor have a better adsorption performance, compared to the composite oxides prepared with other carboxylate coordination precursors. The Cr（Ⅵ） can be effectively removed from aqueous solution at pH 2.0. The adsorption kinetics follows the pseudo-secondorder model and the adsorption rate is greater.