Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resource and Environment, Southwest University, No. 2 Tiansheng Road Beibei, Chongqing, 400715, People's Republic of China.
Chongqing Engineering Research Center of Rural Cleaning, Chongqing, 400716, People's Republic of China.
Environ Sci Pollut Res Int. 2019 Jun;26(17):17321-17332. doi: 10.1007/s11356-019-05081-6. Epub 2019 Apr 23.
Adsorption plays an important role in removing cadmium (Cd) from water, and magnetic adsorbents are increasingly being used due to their ease of separation and recovery. Magnetic FeO-coated hydroxyapatite (HAP) nanoparticles (nHAP-FeO) were developed by co-precipitation and then used for the removal of Cd from water. The properties of these nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and magnetization curves. Experiments were conducted to investigate the effects of adsorption and mechanisms. Results illustrated that kinetic data were well fitted by a pseudo-second-order model. The adsorption capacity of nHAP-FeO was 62.14 mg/g. The mechanisms for the adsorption of Cd on nHAP-FeO included rapid surface adsorption, intraparticle diffusion, and internal particle bonding, with the ion exchange with Ca and chemical complexation being the most dominant. The regeneration efficiency and recovery rate of nHAP-FeO eluted by EDTA-Na after the fifth cycle were 63.04% and 40.2%, respectively. Results revealed that the feasibility of nHAP-FeO as an adsorbent of Cd and its environmental friendliness make it an ideal focus for future research.
吸附在去除水中的镉（Cd）方面起着重要作用，由于其易于分离和回收，磁性吸附剂越来越受到关注。通过共沉淀法制备了磁性 FeO 包覆羟基磷灰石（HAP）纳米颗粒（nHAP-FeO），并将其用于从水中去除 Cd。通过透射电子显微镜、X 射线衍射、傅里叶变换红外光谱和磁化曲线对这些纳米颗粒的性质进行了表征。进行了实验以研究吸附和机制的影响。结果表明，动力学数据很好地符合拟二级模型。nHAP-FeO 的吸附容量为 62.14mg/g。Cd 在 nHAP-FeO 上的吸附机制包括快速表面吸附、颗粒内扩散和内部颗粒键合，其中离子交换与 Ca 和化学络合是最主要的。经过五次循环后，用 EDTA-Na 洗脱的 nHAP-FeO 的再生效率和回收率分别为 63.04%和 40.2%。结果表明，nHAP-FeO 作为 Cd 吸附剂的可行性及其环境友好性使其成为未来研究的理想焦点。
