Division of Biotechnology, Department of Chemistry, Lund University, Lund, Sweden.
Instituto de Investigaciones Fármaco Bioquímicas, Universidad Mayor de San Andrés, La Paz, Bolivia.
Environ Technol. 2020 Sep;41(23):3043-3054. doi: 10.1080/09593330.2019.1596167. Epub 2019 Apr 3.
In this study, we developed a nanoparticle-based mesoporous composite that consisted of silicate-titanate nanotubes (STNTs) supported in hydrogel chitosan beads (STNTs-Ch beads) and was studied for Cd adsorption. By using Fourier-transform infrared spectroscopy, transmission and scanning electron microscopy coupled to an energy-dispersive X-ray spectrometer, we could determine that the hollow STNTs were highly dispersed in the walls of the hollow beads. The dispersion was attributed to the effect of pH when the composite was prepared and we observed a non-interaction between STNTs and chitosan. The adsorption studies of Cd showed that the kinetic rate ( ) increased 3-fold and that the diffusion rate ( ) increased 2-fold after the embedment. Moreover, the maximum capacity of adsorption of STNTs-Ch beads was 2.3 times higher than that of STNTs alone. The treatment of a synthetic Cd solution and a real leachate in continuous mode showed two phases in which it was observed higher removed fractions of transition metal ions (Cd, Co, Ni, Zn and Cu) and the post-transition metal ion Pb, in comparison to the removed fractions of alkali and alkali-earth metal ions (Ca, K, Mg). The composite was successfully reused four times when adsorbing Cd, saving three times the needed amounts of TiO, SiO and chitosan for the production of the material. This composite was produced in a simple way and shows the potential for wastewater treatment.
在这项研究中，我们开发了一种基于纳米颗粒的介孔复合材料，由负载在水凝胶壳聚糖珠中的硅酸盐-钛酸盐纳米管（STNTs）组成，并研究了其对 Cd 的吸附性能。通过傅里叶变换红外光谱、透射电子显微镜和扫描电子显微镜结合能量色散 X 射线光谱仪，我们可以确定空心 STNTs 高度分散在空心珠的壁中。这种分散归因于复合材料制备时 pH 的影响，并且我们观察到 STNTs 和壳聚糖之间没有相互作用。Cd 的吸附研究表明，嵌入后动力学速率（ ）增加了 3 倍，扩散速率（ ）增加了 2 倍。此外，STNTs-Ch 珠的最大吸附容量比单独的 STNTs 高 2.3 倍。在连续模式下处理合成的 Cd 溶液和实际浸出液时，观察到过渡金属离子（Cd、Co、Ni、Zn 和 Cu）和后过渡金属离子 Pb 的去除分数比碱金属和碱土金属离子（Ca、K、Mg）的去除分数更高。当吸附 Cd 时，该复合材料成功地重复使用了四次，节省了生产该材料所需的 TiO2、SiO2 和壳聚糖的三倍量。这种复合材料的制备方法简单，具有处理废水的潜力。
