Multifunctional β-Cyclodextrin-EDTA-Chitosan polymer adsorbent synthesis for simultaneous removal of heavy metals and organic dyes from wastewater

• Published in: Environmental pollution (1987) 2022-01, Vol.292, p.118447-118447, Article 118447
• Main Authors: Verma, Monu, Lee, Ingyu, Hong, Youngmin, Kumar, Vinod, Kim, Hyunook
• Format: Article
• Language: English
• Subjects: Adsorption isotherms; Adsorption mechanism; Amino-β-cyclodextrin; Heavy metal ions; Organic dyes; Simultaneous adsorption
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2021.118447

Heavy metals and organic dyes are the major source of water pollution. Herein, a trifunctional β−cyclodextrin−ethylenediaminetetraacetic acid−chitosan (β−CD−EDTA−CS) polymer was synthesized using an easy and simple chemical route by the reaction of activated β−CD with CS through EDTA as a cross-linker (amidation reaction) for the removal of inorganic and organic pollutants from aqueous solution under different parameters such as pH, time effect, initial concentration, reusability, etc. The synthesized adsorbent was characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, field scanning electron microscopy, energy dispersive spectroscopy, Brunauer-Emmett-Teller (BET), thermogravimetric analyzer techniques to investigate their structural, functional, morphological, elemental compositions, surface area and thermal properties, respectively. Two types of heavy metals, i.e., mercury (Hg2+) and cadmium (Cd2+), and three organic dyes, i.e., methylene blue (MB), crystal violet (CV) and safranin O (SO) were chosen as inorganic and organic pollutants, respectively, to study the adsorption capacity of β-CD-EDTA-CS in aqueous solution. The β-CD-EDTA-CS shows monolayer adsorption capacity 346.30 ± 14.0 and 202.90 ± 13.90 mg g−1 for Hg2+ and Cd2+, respectively, and a heterogeneous adsorption capacity 107.20 ± 5.70, 77.40 ± 5.30 and 55.30 ± 3.60 mg g−1 for MB, CV and SO, respectively. Kinetics results followed pseudo-second order (PSO) kinetics behavior for both metal ions and dyes, and higher rate constants values (0.00161–0.00368 g mg−1 min−1) for dyes confirmed the cavitation of organic dyes (physisorption). In addition, we have also demonstrated the performance of β-CD-EDTA-CS for the of four heavy metals Hg2+, Cd2+, Ni2+, and Cu2+ and three dyes MB, CV, and SO in secondary treated wastewater. Findings of this study indicate that β-CD-EDTA-CS simple and essay to synthesize and can be use in wastewater treatment. [Display omitted] •Trifunctional β-CD-EDTA-CS polymer adsorbent was synthesized.•Two heavy metals and three organic dyes were selected for adsorption in water.•Metal ions capacity enhanced in dyes presence due to synergetic effect.•Elemental mapping, EDS and FTIR analysis confirmed the adsorption mechanism.•Four heavy metals and three dyes were selected for adsorption from real wastewater.