Synthesis and adsorption performance of carboxyl-functionalized magnetic agarose gel microspheres for Cu(II) removal

• Published in: Journal of environmental chemical engineering Vol. 12; no. 3; p. 112582
• Main Authors: Ma, Mingze, Liang, Guanglin, Ru, Yi, Chen, Jun, Zhang, Yonghui, Weng, Huifen, Xiao, Anfeng, Xiao, Qiong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Carboxyl functionalization; Heavy metal adsorption; Magnetic agarose microspheres; Magnetic agarose microspheres; Carboxyl functionalization; Heavy metal adsorption
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2024.112582

Succinic anhydride modified magnetic agarose microspheres (SA-MAM) were synthesized to develop a novel, high-performance, and highly efficient adsorbent for heavy metal ions. Fe3O4 magnetic nanoparticles (MNPs) were prepared via chemical co-precipitation. Magnetic agarose microspheres (MAMs) with different particle sizes and fast magnetic separation rates were prepared using an emulsion embedding method. MAMs with high specific surface area (10 μm, MAM-10) and high magnetic responsiveness (125 μm, MAM-125) were surface functionalized with carboxyl groups by using succinic anhydride (SA) in a non-homogeneous system. The results demonstrated that SA-MAM-10 exhibited a maximum Cu(II) adsorption capacity of 128.8 mg/g. This value was 60.4% higher than that of MAM-10 (80.3 mg/g), approximately 67.1% higher than that of commercial Magarose-COOH (10–30 μm, 77.1 mg/g), and comparable with that of commercial Magarose-NH2 (10–30 μm, 133.1 mg/g). By contrast, SA-MAM-125 maintained high magnetic responsiveness while achieving a maximum adsorption capacity of 76.3 mg/g, which was 21.7% higher than that of MAM-125 (62.7 mg/g) and surpassed the performance of Magarose-COOH (30–150 μm, 66.7 mg/g). Complete separation was achieved within 3 s under the influence of an external magnetic field. Overall, these two types of MAMs exhibited excellent performance in removing Cu(II) from water, highlighting their potential as adsorbents for wastewater purification. [Display omitted] •Spherical and condensed core–shell magnetic agarose particles were prepared.•Agarose microspheres possessed abundant carboxyl groups in the pores of architecture.•Magnetism and adsorption of Cu2+ were perfectly combined into one single entity.•The adsorption fits well with the Langmuir and Freundlich thermodynamic models.•Easy separation and good reusability make the adsorbent attractive for sewage treatment.