Li Yu-Jiao, Yang Zhi-Min, Chen Yu-Cheng, Huang Lei, Tang Hai-Yan
Chongqing Engineering Research Center of Rural Cleaning, College of Resources and Environment, Southwest University, Chongqing 400716, China.
Huan Jing Ke Xue. 2019 Apr 8;40(4):1849-1856. doi: 10.13227/j.hjkx.201808020.
In order to improve the adsorption-separation of Cd in water treatment, magnetic FeO coated Ca(HPO) nanoparticles (NMCDP) were developed by coprecipitation. The properties of these nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and magnetization curves. Experiments were carried out to investigate the effect of adsorption, reclaiming, and regeneration. The results showed that NMCDP was a stable material with a particle size of 60 nm and a saturation magnetization of 30.9 emu·g. The adsorption rate of Cd by NMCDP was fast, and adsorption equilibrium could be achieved within 1 hour. The kinetic data were well fitted by a pseudo-second-order model, and the isotherm adsorption data agreed with the Langmuir and Freundlich model, with a maximum adsorption capacity of 142.50 mg·g. The adsorption capacity of Cd was affected by the pH and increased when the pH was increased from 2 to 3, while with continued increase of the pH of the solution, the adsorption capacity gradually became stable. The coexisting ions in the solution had an effect on the adsorption of Cd, especially the divalent cation Cu. The NMCDP could be regenerated by using 0.01 mol·L HCl and EDTA-Na, and the results indicated that it could be recycled with a desorption rate of 68% by EDTA-Na solution.
为了改善水处理中镉的吸附分离性能，通过共沉淀法制备了磁性FeO包覆的Ca(HPO)纳米颗粒（NMCDP）。采用透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和磁化曲线对这些纳米颗粒的性能进行了表征。进行了吸附、回收和再生效果的实验研究。结果表明，NMCDP是一种稳定的材料，粒径为60 nm，饱和磁化强度为30.9 emu·g。NMCDP对镉的吸附速率较快，1小时内即可达到吸附平衡。动力学数据符合准二级模型，等温吸附数据符合Langmuir和Freundlich模型，最大吸附容量为142.50 mg·g。镉的吸附容量受pH值影响，pH值从2增加到3时吸附容量增加，而随着溶液pH值的继续升高，吸附容量逐渐趋于稳定。溶液中共存离子对镉的吸附有影响，尤其是二价阳离子Cu。NMCDP可用0.01 mol·L HCl和EDTA-Na进行再生，结果表明用EDTA-Na溶液再生时脱附率为68%，可实现循环利用。
