He Chuxian, Qu Junhao, Yu Zihua, Chen Daihuan, Su Tiantian, He Lei, Zhao Zike, Zhou Chunxia, Hong Pengzhi, Li Yong, Sun Shengli, Li Chengyong
School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang 524088, China.
Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China.
Nanomaterials (Basel). 2019 Jun 30;9(7):953. doi: 10.3390/nano9070953.
Micro-nano composite material was prepared to adsorb Hg(II) ions via the co-precipitation method. Oyster shell (OS), FeO nanoparticles, and humic acid (HA) were used as the raw materials. The adhesion of nanoparticles to OS displayed by scanning electron microscopy (SEM), the appearance of the (311) plane of standard FeO derived from X-ray diffraction (XRD), and the transformation of pore sizes to 50 nm and 20 μm by mercury intrusion porosimetry (MIP) jointly revealed the successful grafting of HA-functionalized FeO onto the oyster shell surface. The vibrating sample magnetometer (VSM) results showed superparamagnetic properties of the novel adsorbent. The adsorption mechanism was investigated based on X-ray photoelectron spectroscopy (XPS) techniques, which showed the process of physicochemical adsorption while mercury was adsorbed as Hg(II). The effects of pH (3-7), initial solution concentration (2.5-30 mg·L), and contact time (0-5 h) on the adsorption of Hg(II) ions were studied in detail. The experimental data were well fitted to the Langmuir isotherm equation (R = 0.991) and were shown to follow a pseudo-second-order reaction model (R = 0.998). The maximum adsorption capacity of Hg(II) was shown to be 141.57 mg·g. In addition, this new adsorbent exhibited excellent selectivity.
采用共沉淀法制备了用于吸附汞离子的微纳复合材料。以牡蛎壳（OS）、FeO纳米颗粒和腐殖酸（HA）为原料。扫描电子显微镜（SEM）显示纳米颗粒与OS的附着情况，X射线衍射（XRD）显示标准FeO（311）晶面的出现，压汞法（MIP）显示孔径转变为50 nm和20 μm，共同表明HA功能化的FeO成功接枝到牡蛎壳表面。振动样品磁强计（VSM）结果表明该新型吸附剂具有超顺磁性。基于X射线光电子能谱（XPS）技术研究了吸附机理，结果表明汞以Hg（II）形式被吸附时存在物理化学吸附过程。详细研究了pH值（3 - 7）、初始溶液浓度（2.5 - 30 mg·L）和接触时间（0 - 5 h）对Hg（II）离子吸附的影响。实验数据与Langmuir等温线方程拟合良好（R = 0.991），并表明遵循准二级反应模型（R = 0.998）。Hg（II）的最大吸附容量为141.57 mg·g。此外，这种新型吸附剂表现出优异的选择性。
