Department of Environmental Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Environmental Applications of Recycled and Natural Materials (EARN) Laboratory, Khon Kaen University, Khon Kaen, 40002, Thailand.
Sci Rep. 2022 Oct 13;12(1):17184. doi: 10.1038/s41598-022-22182-4.
Lead contamination in wastewater may affect aquatic organisms, the environment, and human consumption because it is a highly toxic metal that caused human health effects. Thus, it is recommended to remove lead before releasing it into the environment. Powdered and beaded chitosan materials modified with ZnO were synthesized and investigated by various characterized techniques. Lead removal efficiencies of chitosan materials were studied by batch experiments, adsorption isotherms, and kinetics. Chitosan powder (CP), chitosan beads (CB), chitosan beads mixed ZnO (CZB), and chitosan beads coated ZnO (ZCB) were synthesized. CP represented a semi-crystalline structure while CB was an amorphous structure. CZB and ZCB were semi-crystalline structures with ZnO peaks. CP was a scaly-sheet and coarse surface while CB, CZB, and ZCB were sphere shapes with scaly-sheet surfaces. C, O, and N were the main chemical elements in chitosan materials, and Zn was detected in CZB and ZCB. O-H, N-H, and C-O were the main functional groups of chitosan materials. All chitosan materials had high lead removal efficiencies of more than 92%, and Freundlich and pseudo-second-order kinetic models well explained their adsorption patterns and mechanisms. Therefore, both adding metal oxide and changing material form are recommended for improving material efficiency, and ZCB was a good offer for further industrial applications.
废水中的铅污染可能会影响水生生物、环境和人类消费，因为它是一种高度有毒的金属，会对人类健康造成影响。因此，建议在将其排放到环境中之前去除铅。本文通过各种特性技术合成并研究了用 ZnO 改性的粉末状和珠状壳聚糖材料。通过批量实验、吸附等温线和动力学研究了壳聚糖材料的除铅效率。合成了壳聚糖粉末（CP）、壳聚糖珠（CB）、混合 ZnO 的壳聚糖珠（CZB）和涂覆 ZnO 的壳聚糖珠（ZCB）。CP 表现出半结晶结构，而 CB 是无定形结构。CZB 和 ZCB 是具有 ZnO 峰的半结晶结构。CP 呈鳞片状和粗糙表面，而 CB、CZB 和 ZCB 呈球形且具有鳞片状表面。C、O 和 N 是壳聚糖材料的主要化学元素，而 CZB 和 ZCB 中检测到 Zn。O-H、N-H 和 C-O 是壳聚糖材料的主要官能团。所有壳聚糖材料的除铅效率均超过 92%，且 Freundlich 和拟二级动力学模型很好地解释了它们的吸附模式和机制。因此，建议同时添加金属氧化物和改变材料形式以提高材料效率，并且 ZCB 是进一步工业应用的良好选择。
