College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
Carbohydr Polym. 2021 Jun 1;261:117891. doi: 10.1016/j.carbpol.2021.117891. Epub 2021 Mar 3.
In this study, three magnetic flocculants, namely, MC, MC-g-PAM, and MC-g-PAA, were prepared. The structure characteristics, flocculation performance, and floc characteristics of the three magnetic flocculants were systematically studied and compared. SEM, FT-IR, XPS, XRD, TG-DSC, and VSM characterization results show that MC, MC-g-PAM, and MC-g-PAA are successfully prepared and exhibit good magnetic induction. The removal rates of copper ions by MC, MC-g-PAM, and MC-g-PAA under the optimal coagulation conditions are 93.39 %, 88.64 %, and 61.41 %, respectively. Kinetic fitting shows that the flocculation reaction process of MC and MC-g-PAM conforms to pseudo first-order kinetics, while the flocculation reaction process of MC-g-PAA conforms to pseudo second-order kinetics. The flocs produced by MC-g-PAA have larger particle size and fractal dimension than those by MC and MC-g-PAM. At 80 mg/L dosage and pH 6, the floc size and floc fractal dimension obtained by MC-g-PAA reach the maximum values of 48.28 um and 1.468, respectively. Zeta potential studies show that the flocculation functions of the three flocculants are mainly adsorption bridging, adsorption electric neutralization, and chelating precipitation. Recycling experiments show that MC-g-PAA has good recyclability, and the recovery rate after the fifth use is 77.24 % with the Cu(II) removal rate of 67.53 %.
在这项研究中，制备了三种磁絮凝剂，即 MC、MC-g-PAM 和 MC-g-PAA。系统研究和比较了这三种磁絮凝剂的结构特征、絮凝性能和絮体特性。SEM、FT-IR、XPS、XRD、TG-DSC 和 VSM 表征结果表明，MC、MC-g-PAM 和 MC-g-PAA 成功制备，具有良好的磁感应强度。在最佳混凝条件下，MC、MC-g-PAM 和 MC-g-PAA 对铜离子的去除率分别为 93.39%、88.64%和 61.41%。动力学拟合表明，MC 和 MC-g-PAM 的絮凝反应过程符合准一级动力学，而 MC-g-PAA 的絮凝反应过程符合准二级动力学。MC-g-PAA 产生的絮体具有比 MC 和 MC-g-PAM 更大的粒径和分形维数。在 80mg/L 用量和 pH 6 条件下，MC-g-PAA 获得的絮体粒径和絮体分形维数分别达到 48.28μm 和 1.468 的最大值。Zeta 电位研究表明，三种絮凝剂的絮凝作用主要是吸附架桥、吸附电中和和螯合沉淀。回收实验表明，MC-g-PAA 具有良好的可回收性，第五次使用后的回收率为 77.24%，Cu(II)去除率为 67.53%。
