1. Modified magnetic chitosan microparticles as novel superior adsorbents with huge "force field" for capturing food dyes.
- Author
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Zheng, Chaofan, Zheng, Huaili, Wang, Yongjuan, Sun, Yongjun, An, Yanyan, Liu, Hongxia, and Liu, Shuang
- Subjects
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CHITOSAN , *COLORING matter in food , *ADSORPTION isotherms , *LANGMUIR isotherms , *MATHEMATICAL models of chemical processes - Abstract
Graphical abstract Highlights • Novel cationic polymer modified magnetic adsorbents (MCDs) were fabricated. • MCDs have huge "force field" owing to strong electrostatic attraction. • MCDs have a high adsorption capacity for food dyes Food Yellow 3 and Acid Yellow 23. • The adsorption capacity decreases slightly with pH changing from 2.0 to 10.0. • Multiple adsorption mechanisms are involved in the food dye adsorption. Abstract In this study, modified magnetic chitosan microparticles (MCDs) were fabricated and used as adsorbents for the removal of Food Yellow 3 (FY3) and Acid Yellow 23 (AY23) from aqueous solution. The magnetic microparticles were characterized by scanning electronic microscope, Brunauer-Emmett-Teller specific surface area, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis, differential scanning calorimetry, and vibrating-sample magnetometer. Then, the effects of pH value, initial dye concentration, and contact time on the adsorption of FY3 and AY23 by MCDs were investigated. Evidently, MCDs showed excellent adsorption performance for both food dyes, and their adsorption capacities (833.33 mg/g for FY3 and 666.67 mg/g for AY23) were considerably higher than those of unmodified adsorbents, which could be attributed to the electrostatic interaction and ion exchange between the grafted cationic polymer and food dyes. Adsorption isotherm and kinetic data of the magnetic microparticles were well fitted by Langmuir isotherm and pseudo-second-order kinetic model, respectively. The regeneration and reusability of MCDs were also explored. Results showed that more than 80% adsorption capacities of MCDs for FY3 and AY23 remained after five adsorption-desorption cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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