School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, PR China.
J Hazard Mater. 2011 Feb 28;186(2-3):971-7. doi: 10.1016/j.jhazmat.2010.11.096. Epub 2010 Dec 1.
Using D311 resin as a template, porous nano-calcium titanate microspheres (PCTOM) were prepared by a citric acid complex sol-gel method and characterized by X-ray diffraction (XRD), SEM and FTIR. The method's adsorption capabilities for heavy metal ions such as lead, cadmium and zinc were studied and adsorption and elution conditions were investigated. Moreover, taking the cadmium ion as an example, the thermodynamics and kinetics of the adsorption were studied. The results show that the microspheres were porous and were made of perovskite nano-calcium titanate. The lead, cadmium and zinc ions studied could be quantitatively retained at a pH value range of 5-8. The adsorption capacities of PCTOM for lead, cadmium and zinc were found to be 141.8 mg g(-1), 18.0 mg g(-1) and 24.4 mg g(-1) respectively. The adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model, where adsorption was an endothermic and spontaneous physical process. The adsorbed metal ions could be completely eluted using 2 mol L(-1) HNO(3) with preconcentration factors over 100 for all studied heavy metal ions. The method has also been applied to the preconcentration and FAAS determination of trace lead, cadmium and zinc ion in water samples with satisfactory results.
以 D311 树脂为模板，采用柠檬酸络合溶胶-凝胶法制备了多孔纳米钛酸钙微球（PCTOM），并用 X 射线衍射（XRD）、SEM 和 FTIR 对其进行了表征。研究了该方法对重金属离子（如铅、镉和锌）的吸附性能，并考察了吸附和解吸条件。此外，以镉离子为例，研究了吸附的热力学和动力学。结果表明，微球具有多孔性，由钙钛矿纳米钛酸钙组成。所研究的铅、镉和锌离子可在 pH 值为 5-8 的范围内被定量保留。PCTOM 对铅、镉和锌的吸附容量分别为 141.8、18.0 和 24.4 mg g(-1)。吸附行为符合 Langmuir 吸附等温线和拟二级动力学模型，吸附是一个吸热和自发的物理过程。用 2 mol L(-1) HNO(3)可将吸附的金属离子完全洗脱，所有研究的重金属离子的预浓缩因子均超过 100。该方法还用于水样中痕量铅、镉和锌离子的预富集和 FAAS 测定，结果令人满意。
