为了有效去除废水中的重金属,设计具有高吸附能力和易于回收的吸附剂是必要的。本文提出了一种新型的磁杂化气凝胶,Fe3O4/纤维素纳米纤维/聚乙烯亚胺/硫醇改性蒙脱土(Fe3O4/CNF/PEI/SHMMT),并探讨了其对Pb2+的吸附性能及机理,Cu2+,和水溶液中的Cd2+。混合气凝胶具有狭缝状多孔结构和许多暴露的活性位点,通过吸附促进金属离子的吸收。Pb2+,Cu2+,杂化气凝胶对Cd2+的吸附遵循二级动力学和Langmuir等温模型,对Pb2+的最大吸附,Cu2+,和Cd2+在25°C,pH=6,800mg/L分别为429.18、381.68和299.40mg/g,分别。吸附过程主要归因于单层化学吸附,自发的吸热反应。FTIR,XPS和DFT研讨证实了Fe3O4/CNF/PEI/SHMMT对Pb2+的吸附机理,Cu2+,和Cd2+主要是螯合,协调,和离子交换。通过DFT计算,Pb2+在杂化气凝胶上的最低吸附能量为-2.37Ha,这表明样品对Pb2+具有较高的吸附亲和力和优先选择性。5个周期后,气凝胶的吸附效率仍>85%。Fe3O4的掺入进步了气凝胶的力学机能。Fe3O4/CNF/PEI/SHMMT具有较快的磁响应能力,吸附后易于分离回收,这是处理重金属离子的一个有前途的潜力。
To efficiently remove heavy metals from wastewater, designing an adsorbent with high adsorption capacity and ease of recovery is necessary. This paper presents a novel magnetic hybridized aerogel, Fe3O4/cellulose nanofiber/polyethyleneimine/thiol-modified montmorillonite (Fe3O4/CNF/PEI/SHMMT), and explores its adsorption performance and mechanism for Pb2+, Cu2+, and Cd2+ in aqueous solutions. The hybrid aerogel has a slit-like porous structure and numerous exposed active sites, which facilitates the uptake of metal ions by adsorption. Pb2+, Cu2+, and Cd2+ adsorption by the hybridized aerogel followed the second-order kinetics and the Langmuir isotherm model, the maximum adsorption of Pb2+, Cu2+, and Cd2+ at 25 °C, pH = 6, 800 mg/L was 429.18, 381.68 and 299.40 mg/g, respectively. The adsorption process was primarily attributed to monolayer chemical adsorption, a spontaneous heat-absorption reaction. FTIR, XPS and DFT studies confirmed that the adsorption mechanisms of Fe3O4/CNF/PEI/SHMMT on Pb2+, Cu2+, and Cd2+ were mainly chelation, coordination, and ion exchange. The lowest adsorption energy of Pb2+ on the hybrid aerogel was calculated to be -2.37 Ha by DFT, which indicates that the sample has higher adsorption affinity and preferential selectivity for Pb2+. After 5 cycles, the adsorption efficiency of the aerogel was still >85 %. The incorporation of Fe3O4 improved the mechanical properties of the aerogel. The Fe3O4/CNF/PEI/SHMMT has fast magnetic responsiveness, and it is easy to be separated and recovered after adsorption, which is a promising potential for the treatment of heavy metal ions.