College of Material Science and Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, PR China.
College of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou 014010, PR China.
Int J Biol Macromol. 2024 Sep;276(Pt 1):133895. doi: 10.1016/j.ijbiomac.2024.133895. Epub 2024 Jul 15.
Efficient harnessing of heavy metal pollution is an urgent environmental task. Herein, magnetic bio adsorbent (MB) based on FeO-chitosan-graphene oxide composite was fabricated via one step co-precipitation for adsorptive remediation of Cu(II). Remediation efficiency was evaluated by batch adsorption, meanwhile adsorption mechanism was elucidated by spectroscopic tests (XPS, UV-Vis absorption and fluorescent emission spectra), statistical physics formalism, isotherm and kinetic fittings. Results show, MB reaches adsorption percent and quantity of 87.61 % and 350.43 mg·g for Cu(II) in 30 min. By virtue of paramagnetism, MB can be readily recovered with a permanent magnet for easy regeneration and cyclic use, thereby retaining adsorption quantity 279.99 mg·g at the fifth cycle. The Freundlich and pseudo second order model satisfactorily describes the adsorption, designating chemical interaction as the rate limiting step. Statistical physics calculation suggests two points. (1) Multi-ionic adsorption mechanism with exothermic, spontaneous and energy lowering feature. (2) Density of adsorption sites increases with temperature, resulting in improved adsorption capacity. Spectroscopic analysis confirms the involvement of CO, CO, -NH in Cu(II) uptake via electron donation. These explorations contribute with novel theoretical illumination for understanding both the thermodynamic feature and atomic scale mechanism of common pollutants adsorption by bio adsorbent like FeO-chitosan-graphene oxide.
高效利用重金属污染是一项紧迫的环境任务。在此，通过一步共沉淀法制备了基于 FeO-壳聚糖-氧化石墨烯复合材料的磁性生物吸附剂（MB），用于 Cu(II) 的吸附修复。通过批量吸附实验评估了修复效率，同时通过光谱测试（XPS、UV-Vis 吸收和荧光发射光谱）、统计物理形式、等温线和动力学拟合来阐明吸附机制。结果表明，MB 在 30 分钟内达到 87.61%的 Cu(II)吸附百分率和 350.43mg·g 的吸附量。由于具有顺磁性，MB 可以很容易地用永磁体回收，从而易于再生和循环使用，因此在第五个循环中保留了 279.99mg·g 的吸附量。Freundlich 和准二级模型很好地描述了吸附，表明化学相互作用是限速步骤。统计物理计算表明了两点。（1）多离子吸附机制具有放热、自发和能量降低的特点。（2）吸附位点的密度随温度升高而增加，从而提高了吸附容量。光谱分析证实了 CO、CO、-NH 通过电子供体参与了 Cu(II)的摄取。这些探索为理解像 FeO-壳聚糖-氧化石墨烯这样的生物吸附剂对常见污染物的吸附的热力学特征和原子尺度机制提供了新的理论启示。
