用改性磁壳聚糖吸附剂去除汞(II)。

Mercury(II) removal with modified magnetic chitosan adsorbents.

机构信息

Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-541 24, Greece.

出版信息

Molecules. 2013 May 24;18(6):6193-214. doi: 10.3390/molecules18066193.

Two modified chitosan derivatives were prepared in order to compare their adsorption properties for Hg(II) removal from aqueous solutions. The one chitosan adsorbent (CS) is only cross-linked with glutaraldehyde, while the other (CSm), which is magnetic, is cross-linked with glutaraldehyde and functionalized with magnetic nanoparticles (Fe₃O₄). Many possible interactions between materials and Hg(II) were observed after adsorption and explained via characterization with various techniques (SEM/EDAX, FTIR, XRD, DTG, DTA, VSM, swelling tests). The adsorption evaluation was done studying various parameters as the effect of pH (optimum value 5 for adsorption and 2 for desorption), contact time (fitting to pseudo-first, -second order and Elovich equations), temperature (isotherms at 25, 45, 65 °C), in line with a brief thermodynamic analysis (ΔG⁰ < 0, ΔH⁰ > 0, ΔS⁰ > 0). The maximum adsorption capacity (fitting with Langmuir and Freundlich model) of CS and CSm at 25 °C was 145 and 152 mg/g, respectively. The reuse ability of the adsorbents prepared was confirmed with sequential cycles of adsorption-desorption.

为了比较两种改性壳聚糖衍生物对水溶液中 Hg(II) 的吸附性能，制备了两种改性壳聚糖衍生物。一种壳聚糖吸附剂（CS）仅用戊二醛交联，而另一种（CSm）则用戊二醛交联并用磁性纳米粒子（Fe₃O₄）功能化。吸附后，通过各种技术（SEM/EDAX、FTIR、XRD、DTG、DTA、VSM、溶胀试验）对材料与 Hg(II) 之间的多种可能相互作用进行了观察和解释。通过研究各种参数（pH 的影响（吸附的最佳值为 5，解吸的最佳值为 2）、接触时间（拟合伪一级、二级和 Elovich 方程）、温度（25、45、65°C 下的等温线），结合简要的热力学分析（ΔG⁰ < 0、ΔH⁰ > 0、ΔS⁰ > 0）对吸附进行了评估。在 25°C 下，CS 和 CSm 的最大吸附容量（分别拟合 Langmuir 和 Freundlich 模型）分别为 145 和 152 mg/g。通过连续的吸附-解吸循环，证实了所制备的吸附剂的可重复使用能力。