Caspian Faculty of Engineering, College of Engineering, University of Tehran, P.O. Box 43841-119, Rezvanshahr, Iran.
Caspian Faculty of Engineering, College of Engineering, University of Tehran, P.O. Box 43841-119, Rezvanshahr, Iran; Chemistry Department, Missouri University of Science and Technology, Rolla, MO, USA, 65409.
Int J Biol Macromol. 2023 Sep 1;248:125984. doi: 10.1016/j.ijbiomac.2023.125984. Epub 2023 Jul 27.
Recently, natural polymers like chitosan have gained attention as promising adsorbents for water treatment. By combining chitosan with magnetic nanoparticles, their adsorption capabilities can be enhanced. In this study, chitosan-magnetite nanocomposite (CMNC) was synthesized via coprecipitation method to remove nickel and cobalt from aqueous solutions. The physicochemical properties of the synthesized CMNC were investigated by various techniques, including FESEM, TEM, XPS, FTIR, XRD, and VSM. The electron microscopy results confirmed the uniform dispersion of magnetite nanoparticles within CMNC nanocomposites, while VSM confirmed their significant magnetic properties. The adsorption experiments showed that at optimal conditions (pH = 6, contact time = 2 h, adsorbent dosage = 2 g/l), CMNC has high adsorption capacities of 30.03 mg/g for Ni and 53.19 mg/g for Co. Furthermore, the adsorption data fitted best with the Langmuir isotherm, show that the active sites on CMNC are energetically homogenous. According to kinetic analysis, the experimental data were in good agreement with both pseudo-second-order and intra-particle diffusion models, which suggest that chemical sorption, along with mass transfer steps, influence the overall adsorption process. Finally, investigating the thermodynamic parameters (∆G, ∆H, ∆S) showed that the adsorption process on CMNC was endothermic and spontaneous, with stronger interactions observed between CMNC and Co compared to Ni.
最近，壳聚糖等天然聚合物作为水处理的有前途的吸附剂引起了人们的关注。通过将壳聚糖与磁性纳米粒子结合，可以增强它们的吸附能力。在这项研究中，通过共沉淀法合成了壳聚糖-磁铁矿纳米复合材料（CMNC），以去除水溶液中的镍和钴。通过各种技术研究了合成的 CMNC 的物理化学性质，包括 FESEM、TEM、XPS、FTIR、XRD 和 VSM。电子显微镜结果证实了磁铁矿纳米粒子在 CMNC 纳米复合材料中的均匀分散，而 VSM 证实了它们具有显著的磁性。吸附实验表明，在最佳条件下（pH = 6，接触时间 = 2 小时，吸附剂用量 = 2 g/L），CMNC 对 Ni 的吸附容量为 30.03 mg/g，对 Co 的吸附容量为 53.19 mg/g。此外，吸附数据与 Langmuir 等温线拟合最佳，表明 CMNC 上的活性位点在能量上是均匀的。根据动力学分析，实验数据与准二级和内扩散模型都非常吻合，这表明化学吸附以及质量传递步骤会影响整个吸附过程。最后，研究热力学参数（∆G、∆H、∆S）表明，CMNC 上的吸附过程是吸热和自发的，与 Ni 相比，CMNC 与 Co 之间的相互作用更强。
