Efficient adsorption of rhodamine B using synthesized Mg–Al hydrotalcite/ sodium carboxymethylcellulose/ sodium alginate hydrogel spheres: Performance and mechanistic analysis

• Published in: Heliyon 2024-05, Vol.10 (9), p.e30345-e30345, Article e30345
• Main Authors: Chang, Siqi, Zhang, Xiangling, Wang, Chen, Bai, Jing, Li, Xuhao, Liang, Wei, Mao, Yajia, Cai, Jixian, Li, Yifan, Jiang, Yu, Xu, Zhouying
• Format: Article
• Language: English
• Subjects: Carboxymethyl cellulose; Magnesium aluminum hydrotalcite; Rhodamine B; Sodium alginate; Sodium dodecyl sulfate
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e30345

In this study, the sodium dodecyl sulfate intercalated modified magnesium-aluminum hydrotalcite/sodium alginate/sodium carboxymethylcellulose (modified LDHs/SA/CMC) composite gel spheres were synthesized and their efficacies in adsorbing the cationic dye rhodamine B (RhB) from aqueous solutions were evaluated. The effects of adsorption time, pH and temperature on the adsorption of RhB by spheres were investigated. Remarkably, the modified LDHs/SA/CMC gel spheres achieved adsorption equilibrium after 600 min at 25 °C, and the removal rate of RhB at 60 mg/L reached 91.49 % with the maximum adsorption capacity of 59.64 mg/g. The gel spheres maintained over 80 % efficacy across four adsorption cycles. Kinetic and isotherm analyses revealed that the adsorption of RhB conformed to the secondary kinetic model and the Langmuir isotherm, indicating a spontaneous and exothermic nature of the adsorption process. The adsorption mechanisms of modified LDHs/SA/CMC gel spheres on RhB dyes include electrostatic adsorption, hydrogen bonding and hydrophobic interactions. In conclusion, modified LDHs/SA/CMC gel sphere is a green, simple, recyclable and efficient adsorbent, which is expected to be widely used for the treatment of cationic dye wastewater. •Modified MgAl-LDHs/sodium alginate/carboxymethylcellulose gel sphere was successfully prepared.•The adsorption effect on RhB remained 82 % after 4 cycles of use.•Langmuir isotherm and proposed secondary kinetic model fitted the experimental results well.•Adsorption mechanisms include electrostatic adsorption, hydrogen bonding and hydrophobic interactions.