College of Environment and Resources, Guangxi Normal University, Guilin, China; PCH, IMT Mines Ales, Ales, France.
PCH, IMT Mines Ales, Ales, France.
Carbohydr Polym. 2021 Apr 1;257:117588. doi: 10.1016/j.carbpol.2020.117588. Epub 2021 Jan 2.
This study investigates Hg(II) and Cu(II) sorption in single and binary systems by alginate/polyethylenimine membranes. Batch experiments are conducted to assess the metal sorption performance. FTIR and SEM-EDX analyses are used to identify metal binding mechanism. The sorption kinetics are better fitted by the pseudo-second-order-equation compared to the pseudo-first-order-equation. Three isotherms are compared for fitting the sorption in mono-component solutions and the Sips model gives the best simulation of experimental data. The competitive-Sips model fits well sorption data in Hg-Cu binary solutions and finds that the Cu uptake is drastically reduced by Hg competition. Copper(II) uptake remains negligible at low pH whereas it increases with pH up to 6 because of material deprotonation. Mercury(II) sorption behaves differently, it slightly changes from pH 1 (q: 0.76 mmol g) to pH 6 (q: 0.84 mmol g) due to chloro-anion formation. Therefore, playing with the pH allows separating Hg(II) from Cu(II).
本研究通过海藻酸钠/聚乙烯亚胺膜在单一和二元体系中研究 Hg(II) 和 Cu(II) 的吸附。通过批量实验评估金属吸附性能。FTIR 和 SEM-EDX 分析用于确定金属结合机制。与准一级方程相比，吸附动力学更符合拟二级方程。三种等温线用于拟合单一组分溶液中的吸附，Sips 模型对实验数据的模拟效果最好。竞争 Sips 模型很好地拟合了 Hg-Cu 二元溶液中的吸附数据，并发现 Hg 的竞争使 Cu 的吸收大大减少。在低 pH 值下，铜(II)的吸收可以忽略不计，而由于材料去质子化，铜的吸收随着 pH 值增加到 6 而增加。Hg(II)的吸附行为不同，由于氯阴离子的形成，其从 pH 值 1（q：0.76 mmol g）到 pH 值 6（q：0.84 mmol g）略有变化。因此，通过调节 pH 值可以将 Hg(II)与 Cu(II)分离。
