State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
J Hazard Mater. 2022 Feb 5;423(Pt A):127013. doi: 10.1016/j.jhazmat.2021.127013. Epub 2021 Aug 22.
In this work, the superabsorbent polymer hydrogel (SPH) of Poly(potassium acrylate-co-acrylamide (PPAA)) incorporated with Fe-Mn binary oxides (FMBOs) was synthesized and used for the removal of Sb(III) from water. Characterization analysis proved that FMBO was successfully encapsulated into the SPH. The Fe/Mn oxide species in the composite SPH comprised FeO(OH), FeO, MnO(OH), and MnO. The functional groups including N-H, -OH, carboxy as well as Fe atoms were confirmed adsorption sites through ligand exchange and inner-sphere complexes formation. Mn oxides can partially oxidize Sb(III) to Sb(V). Compared with the pseudo-first-order model, the pseudo-second-order model could better describe the adsorption kinetics. And the swelling degree of the composite SPH had a positive impact on the removal rate. The Langmuir-Freundlich model was the most suitable isotherm model to analyze the experimental data. According to thermodynamic parameters, the adsorption process was a spontaneous exothermic reaction. The maximum adsorption capacity of the composite SPH for Sb(III) could be up to 105.59 mg/g at 288 K. In addition, a stable removal rate can be achieved over a wide pH range of 3-10, with little metal leaching even under acidic conditions. Furthermore, coexisting ions and DOM displayed an insignificant influence on the adsorption of Sb(III).
在这项工作中，合成了聚（丙烯酸钾-co-丙烯酰胺（PPAA））基超吸水性聚合物水凝胶（SPH），并将其与 Fe-Mn 二元氧化物（FMBOs）结合，用于从水中去除 Sb(III)。特征分析证明 FMBO 成功地包裹在 SPH 中。复合材料 SPH 中的 Fe/Mn 氧化物物种包括 FeO(OH)、FeO、MnO(OH) 和 MnO。通过配体交换和内球络合物形成，确认了包括 N-H、-OH、羧基和 Fe 原子在内的官能团是吸附位点。Mn 氧化物可以将 Sb(III)部分氧化为 Sb(V)。与伪一阶模型相比，伪二阶模型可以更好地描述吸附动力学。并且复合 SPH 的溶胀度对去除率有积极影响。Langmuir-Freundlich 模型是最适合分析实验数据的等温线模型。根据热力学参数，吸附过程是一个自发的放热反应。在 288 K 时，复合 SPH 对 Sb(III)的最大吸附容量可达 105.59 mg/g。此外，在广泛的 pH 范围 3-10 内可以实现稳定的去除率，即使在酸性条件下也几乎没有金属浸出。此外，共存离子和 DOM 对 Sb(III)的吸附影响不大。
