Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China.
Chongqing Key Laboratory of Catalysis & Functional Organic Molecules, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067, PR China.
J Hazard Mater. 2021 Mar 5;405:124195. doi: 10.1016/j.jhazmat.2020.124195. Epub 2020 Oct 15.
Separating and recovering lead from heavy metal contaminated wastewater is crucial for the environment remediation and reutilization of lead resources. Herein, a novel adsorbent, the phosphorylated chitosan-coated magnetic silica nanoparticles (FeO@SiO@CS-P), was successfully fabricated and applied to highly selective adsorption of lead. Competitive experiments were conducted in a multi-ion solution (7 metal ions coexist) at pH 6.0, FeO@SiO@CS-P exhibited an excellent selectively for capturing lead with the distribution coefficient (0.75 L g) more ten times than other metal, while FeO@SiO@CS demonstrated a highly selective adsorption of silver. These implied that phosphorylation of adsorbent not only improves the sorption performance of lead, but also changes the selective adsorption of metal types. Acidity experiments can draw conclusions that FeO@SiO@CS-P exhibited better acid resistance (with barely any iron leaching) than silica-uncoated adsorbent (FeO@CS-P) at pH 1.0. Furthermore, the FTIR and XPS spectra after adsorption suggested that the high adsorption performance and selective capture lead were predominantly controlled by the coordination of the phosphate groups on the surface of the adsorbent. This work shows a broad prospect of developing a series of novel, acid-resistant, good reusable and rapidly separable magnetic materials that can be used to efficiently and selectively capture lead from aqueous solutions.
从重金属污染废水中分离和回收铅对于环境修复和铅资源的再利用至关重要。在此，成功制备了一种新型吸附剂，即磷酸化壳聚糖包覆的磁性硅纳米粒子（FeO@SiO@CS-P），并将其应用于铅的高选择性吸附。在 pH 值为 6.0 的多离子溶液（7 种金属离子共存）中进行了竞争实验，FeO@SiO@CS-P 对铅的捕获表现出优异的选择性，分配系数（0.75 L/g）是其他金属的十倍以上，而 FeO@SiO@CS 则对银表现出高度选择性的吸附。这表明吸附剂的磷酸化不仅提高了铅的吸附性能，而且改变了金属类型的选择性吸附。酸度实验可以得出结论，在 pH 值为 1.0 时，FeO@SiO@CS-P 比未包覆硅的吸附剂（FeO@CS-P）具有更好的耐酸性（几乎没有铁浸出）。此外，吸附后的 FTIR 和 XPS 谱图表明，吸附剂表面磷酸基团的配位对高吸附性能和选择性捕获铅起主要控制作用。这项工作展示了开发一系列新型、耐酸、良好可重复使用和快速可分离的磁性材料的广阔前景，这些材料可用于从水溶液中高效和选择性地捕获铅。
