College of Sciences, Nanchang Institute of Technology, 289 Tianxiang Avenue, Gaoxin District, Nanchang, 330099, China.
College of Sciences, Nanchang Institute of Technology, 289 Tianxiang Avenue, Gaoxin District, Nanchang, 330099, China.
Chemosphere. 2023 Apr;319:137990. doi: 10.1016/j.chemosphere.2023.137990. Epub 2023 Feb 1.
In order to promote the heavy metal ions removal of porous gel adsorbent and protect the adsorbent from other pollutants in wastewater, the tetrapod ZnO whiskers (tZnO) modified by amino-chain brush was introduced into the polyvinyl alcohol (PVA) matrix to prepare the PVA/NH@TAtZnO composites with brush structure for toxic Pb(II) removal. The adsorption property, adsorption process and adsorption mechanism were studied by adsorption isotherms, adsorption kinetics, adsorption thermodynamics, SEM-EDS analysis and XPS analysis. And the anti-interference ability and anti-interference mechanism were researched by SEM-EDS analysis and XPS analysis. It was found that the PVA/NH@TAtZnO composites displayed a soft-hard compound pore-brush structure and showed a good selective adsorption on Pb(II). The research of isotherms and kinetics indicated that the adsorption process was fitted well to Langmuir model and pseudo-second-order model, respectively, and the research of thermodynamics revealed the endothermic nature. The adsorption mechanism was inferred as the combination of predominant chemisorption and subsidiary physisorption. Comparing with the neat PVA matrix, the PVA/NH@TAtZnO composites displayed a good anti-interference property on Pb(II) adsorption and showed an alleviative clogging pore-canal structure in the wastewater with SiO NPs or PAC flocculants. The anti-interference intensity ΔQ and anti-interference factor χ were proposed to reflect the anti-interference ability of this adsorbent which was promoted with the increasing amino brush length or density. By the analysis of SEM-EDS and XPS, the anti-interference mechanism was explored as the steric-hinerance effect of tZnO hard brush to suspended SiO NPs pollutant and the coordination effect of functional amino soft brush to soluble PAC pollutant. Besides, the prepared PVA/NH@TAtZnO adsorbent possessed a good reusability under multiple adsorption-desorption processes and also presented a well applicability in real water matrix. The research indicated the huge potential of prepared PVA/NH@TAtZnO adsorbent in heavy metal ions removal.
为了提高多孔凝胶吸附剂对重金属离子的去除能力并保护吸附剂免受废水中其他污染物的影响，将氨基链刷修饰的四足氧化锌晶须（tZnO）引入到聚乙烯醇（PVA）基体中，制备了具有刷状结构的 PVA/NH@TAtZnO 复合材料，用于去除有毒的 Pb（II）。通过吸附等温线、吸附动力学、吸附热力学、SEM-EDS 分析和 XPS 分析研究了吸附性能、吸附过程和吸附机理。通过 SEM-EDS 分析和 XPS 分析研究了抗干扰能力和抗干扰机理。结果表明，PVA/NH@TAtZnO 复合材料呈现出软-硬复合孔-刷状结构，对 Pb（II）表现出良好的选择性吸附。等温线和动力学研究表明，吸附过程分别符合 Langmuir 模型和拟二级动力学模型，热力学研究表明该吸附过程是吸热的。吸附机理推断为主要的化学吸附和次要的物理吸附的结合。与纯 PVA 基体相比，PVA/NH@TAtZnO 复合材料对 Pb（II）吸附具有良好的抗干扰能力，并且在含有 SiO NPs 或 PAC 絮凝剂的废水中显示出减轻的堵塞孔-道结构。提出了抗干扰强度ΔQ 和抗干扰因子 χ 来反映该吸附剂的抗干扰能力，这是通过增加氨基刷的长度或密度来提高的。通过 SEM-EDS 和 XPS 分析，探索了抗干扰机制，即 tZnO 硬刷对悬浮 SiO NPs 污染物的空间位阻效应和官能团软刷对可溶性 PAC 污染物的配位效应。此外，在多次吸附-解吸过程中，所制备的 PVA/NH@TAtZnO 吸附剂具有良好的可重复使用性，并且在实际水基质中也具有良好的适用性。研究表明，所制备的 PVA/NH@TAtZnO 吸附剂在去除重金属离子方面具有巨大的潜力。
