Synthesis and study of poly (phthalic anhydride-β-cyclodextrin) for the efficient adsorption of cationic dyes from industrial wastewater

• Published in: Chemical engineering research & design 2023-06, Vol.194, p.768-778
• Main Authors: Sun, Suning, Yu, Erlei, Hu, Rui, Li, Yao, Wei, Zhong
• Format: Article
• Language: English
• Subjects: Adsorption; Cationic dyes; Phthalic anhydride; β-CD
• ISSN: 0263-8762
• DOI: 10.1016/j.cherd.2023.05.025

In this study, a novel adsorbent capable of efficiently adsorbing cationic dyes, poly (phthalic anhydride-β-cyclodextrin) (PhAEs-β-CD), was synthesized by self-cross-linking of phthalic anhydride (PhA)-modified-β-cyclodextrin. The PhA cross-linker plays a dual role of providing coordination sites for cationic dye binding and contributing to the large specific surface area owing to the existence of rigid aromatic groups. The adsorption properties of PhAEs-β-CD for cationic dyes were investigated, and the results revealed that the adsorbent contains numerous functional groups and has a high specific surface area (332.14 m2/g), which is highly beneficial for cationic dye removal. The maximum adsorption capacities of PhAEs-β-CD were found to be 3288.80 mg·g−1 for basic green 4, 2407.87 mg·g−1 for crystal violet, 2264.40 mg·g−1 for astrazon pink FG, and 1401.33 mg·g−1 for methylene blue. The adsorption mechanism and system were modeled by using the Langmuir isotherm model and the pseudo-second-order kinetic model. The removal efficiency of the adsorbent for basic green 4 reached more than 90 % even after five regeneration cycles, indicating that the adsorbent had good regenerative capacity. These findings demonstrated the potential application of PhAEs-β-CD in dye wastewater treatment. [Display omitted] •A noval β-cyclodextrin based adsorbent (PhAEs-β-CD) was prepared by phthalic anhydride modified β-cyclodextrin.•The synthesis of PhAEs-β-CD is simple, with high specific surface area and abundant active groups.•PhAEs-β-CD exhibited high adsorption capacities for cationic dyes.•The regeneration efficiency of PhAEs-β-CD remained above 90 % after the fifth cycle.