Zhao Yu-Ying, Lin Jian-Wei, Zhang Hong-Hua, Zhang Zhi-Bin, Zhan Yan-Hui, Jiang Bo-Hui, He Si-Qi, Yu Yang, Wu Xiao-Long, Wang Yan, Chen Lu, Li Shi-Sheng
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
Huan Jing Ke Xue. 2019 Feb 8;40(2):658-668. doi: 10.13227/j.hjkx.201806232.
Two kinds of magnetic zirconium/iron-modified bentonites (ZrFeBTs), including magnetic zirconium/iron modified raw bentonite (ZrFeRBT) and magnetic zirconium/iron-modified Ca-pretreated bentonite, (ZrFeCaBT) were prepared and characterized. Their phosphate adsorption characteristics were compared to determine the effect of the Ca pre-treatment on the adsorption of phosphate onto ZrFeBTs. The results showed that the as-prepared ZrFeBTs contained FeO and Zr, and the content of exchangeable Ca in ZrFeCaBT was much higher than that in ZrFeRBT. The adsorption isotherm data exhibited good agreement with the Langmuir isotherm model, with maximum monolayer phosphate adsorption capacities of 8.70 mg·g and 11.5 mg·g for ZrFeRBT and ZrFeCaBT, respectively. The isotherm and kinetics studies showed that the adsorption of phosphate on ZrFeBTs was a chemisorption process. The phosphate adsorption capacities for ZrFeBTs decreased with increasing solution pH. The ZrFeBTs exhibited a high selective adsorption for phosphate in the presence of anions and cations, including Cl, HCO, SO, NO, Na, K, Mg, and Ca. Furthermore, coexisting Ca greatly enhanced the adsorption of phosphate onto ZrFeBTs. The pre-treatment of raw bentonite with Ca significantly improved the adsorption of phosphate onto ZrFeBTs.
制备并表征了两种磁性锆/铁改性膨润土（ZrFeBTs），包括磁性锆/铁改性原膨润土（ZrFeRBT）和磁性锆/铁改性钙预处理膨润土（ZrFeCaBT）。比较了它们对磷酸盐的吸附特性，以确定钙预处理对ZrFeBTs吸附磷酸盐的影响。结果表明，所制备的ZrFeBTs含有FeO和Zr，ZrFeCaBT中可交换钙的含量远高于ZrFeRBT。吸附等温线数据与Langmuir等温线模型吻合良好，ZrFeRBT和ZrFeCaBT对磷酸盐的最大单层吸附容量分别为8.70 mg·g和11.5 mg·g。等温线和动力学研究表明，磷酸盐在ZrFeBTs上的吸附是一个化学吸附过程。ZrFeBTs对磷酸盐的吸附容量随溶液pH值的升高而降低。ZrFeBTs在存在Cl、HCO、SO、NO、Na、K、Mg和Ca等阴离子和阳离子的情况下，对磷酸盐表现出高选择性吸附。此外，共存的钙极大地增强了磷酸盐在ZrFeBTs上的吸附。用钙对原膨润土进行预处理显著提高了ZrFeBTs对磷酸盐的吸附。
