Saberi-Zare Maryam, Bodaghifard Mohammad Ali
Department of Chemistry, Faculty of Science, Arak University, Arak 38481-77584, Iran.
Department of Chemistry, Faculty of Science, Arak University, Arak 38481-77584, Iran; Institute of Nanosciences &Nanotechnology, Arak University, Arak, Iran.
Int J Biol Macromol. 2025 Mar;296:139794. doi: 10.1016/j.ijbiomac.2025.139794. Epub 2025 Jan 11.
The rapid industrialization and human activities in catchments have posed notable global challenges in removing of heavy metal contaminants from wastewater. Here, Schiff-bases (SB) of cyanoguanidine (CG) and salicylaldehyde (SA) were covalently grafted on a magnetic nanocomposite of chitosan to form a hybrid magnetic nanostructure (FeO@CS-CGSB). The synthesized structure was characterized using various techniques such as Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), zeta potential, and Brunauer-Emmett-Teller surface area analysis (BET). The prepared adsorbent demonstrated strong binding capabilities and high efficiency in adsorbing Pb(II) and Cd(II) metal ions from aqueous solutions with removal efficiencies of 98 % and 97 %, respectively. The study investigated various factors such as pH, adsorbate concentration, adsorbent dosage, isotherms, kinetics, and adsorption mechanism. The heavy metal ions were adsorbed through coordination with the nitrogen and hydroxyl groups of the nanostructure, as well as electrostatic interactions. The adsorption process followed the Freundlich isotherm with a high correlation coefficient (R = 0.97, 0.96) and a pseudo-second-order kinetic model. The FeO@CS-CGSB is highly effective in removing heavy metal ions with maximum adsorption capacities of 394 mg/g for Pb(II) and 391 mg/g for Cd(II). The recycled hybrid nanostructure was dried and subjected to various adsorption-desorption tests, revealing a desorption efficiency of 98 %. In conclusion, the synthesized magnetic bio-sorbent shows great promise in effectively removing heavy metal ions from water and wastewater.
集水区的快速工业化和人类活动在从废水中去除重金属污染物方面带来了显著的全球挑战。在此，氰基胍（CG）和水杨醛（SA）的席夫碱（SB）被共价接枝到壳聚糖的磁性纳米复合材料上，形成一种杂化磁性纳米结构（FeO@CS-CGSB）。使用傅里叶变换红外光谱（FT-IR）、场发射扫描电子显微镜（SEM）、透射电子显微镜（TEM）、粉末X射线衍射（XRD）、热重分析（TGA）、振动样品磁强计（VSM）、动态光散射（DLS）、zeta电位和布鲁诺尔-埃米特-泰勒表面积分析（BET）等各种技术对合成结构进行了表征。所制备的吸附剂在从水溶液中吸附Pb(II)和Cd(II)金属离子方面表现出强大的结合能力和高效率，去除效率分别为98%和97%。该研究考察了pH值、吸附质浓度、吸附剂用量、等温线、动力学和吸附机理等各种因素。重金属离子通过与纳米结构的氮和羟基基团配位以及静电相互作用被吸附。吸附过程遵循弗伦德里希等温线，相关系数较高（R = 0.97, 0.96），并符合准二级动力学模型。FeO@CS-CGSB在去除重金属离子方面非常有效，对Pb(II)的最大吸附容量为394 mg/g，对Cd(II)为391 mg/g。回收的杂化纳米结构经过干燥并进行了各种吸附-解吸测试，解吸效率为98%。总之，合成的磁性生物吸附剂在有效去除水和废水中的重金属离子方面显示出巨大的潜力。
