School of Chemistry and Bioengineering, Hechi University, Yizhou, Guangxi, 546300, PR China; Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, PR China.
Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, PR China.
Chemosphere. 2023 Mar;318:137869. doi: 10.1016/j.chemosphere.2023.137869. Epub 2023 Jan 28.
Heavy metals and azo dyes caused huge harm to the aqueous system and human health. A magnetic chitosan/polyethyleneimine embedded hydrophobic sodium alginate composite (MCPS) was designed and prepared to simultaneously remove aqueous same ionic type heavy metals and azo dyes. In mono-polluted system, the optimal pH for Cr(VI), MO (methyl orange), Cu(Ⅱ) and MB (methylene blue) were 3, 2, 6 and 12 with a saturated adsorption capacity of 87.53, 66.41, 351.03 and 286.54 mg/g, respectively. Pseudo-second-order was suitable to describe the adsorption kinetics of them and the adsorption isotherms were more consistent with the Langmuir isotherm model being a spontaneous, endothermic, and entropy-increasing process. In binary-polluted system, MCPS possessed simultaneous adsorption for Cr (Ⅵ)-MO and Cu(Ⅱ)-MB pollutants at their optimal pH, in addition, whether in anionic or cationic solution, the removal of heavy metals were promoted with the add of azo dyes but the removal of azo dyes were suppressed with the add of heavy metals. Both Cr (Ⅵ)-MO and Cu(Ⅱ)-MB pollutants could be effectively adsorbed and desorbed from MCPS by changing the pH of the aqueous solution to realize recyclability. Lastly, removal mechanism was revealed in detail by FT-IR, EDS and XPS.
重金属和偶氮染料对水系统和人类健康造成了巨大的危害。设计并制备了一种磁性壳聚糖/聚乙烯亚胺嵌入疏水性海藻酸钠复合材料（MCPS），以同时去除水相中同类型的重金属和偶氮染料。在单一污染体系中，Cr(VI)、MO（甲基橙）、Cu(Ⅱ)和 MB（亚甲基蓝）的最佳 pH 值分别为 3、2、6 和 12，饱和吸附容量分别为 87.53、66.41、351.03 和 286.54mg/g。准二级动力学模型更适合描述它们的吸附动力学，吸附等温线更符合 Langmuir 等温模型，表明该吸附过程是自发的、吸热的和熵增加的过程。在二元污染体系中，MCPS 在其最佳 pH 值下对 Cr(Ⅵ)-MO 和 Cu(Ⅱ)-MB 污染物具有同时吸附作用，此外，无论在阴离子还是阳离子溶液中，随着偶氮染料的加入，重金属的去除都得到了促进，而随着重金属的加入，偶氮染料的去除受到了抑制。通过改变水溶液的 pH 值，MCPS 可以有效地吸附和脱附 Cr(Ⅵ)-MO 和 Cu(Ⅱ)-MB 污染物，从而实现可重复使用性。最后，通过 FT-IR、EDS 和 XPS 详细揭示了去除机制。
