Alkali pretreated sugarcane bagasse, rice husk and corn husk wastes as lignocellulosic biosorbents for dyes

• Published in: Carbohydrate polymer technologies and applications 2021-12, Vol.2, p.100061, Article 100061
• Main Authors: Ponce, Julia, Andrade, João Gabriel da Silva, dos Santos, Luciana Nunes, Bulla, Milena Keller, Barros, Beatriz Cervejeira Bolanho, Favaro, Silvia Luciana, Hioka, Noboru, Caetano, Wilker, Batistela, Vagner Roberto
• Format: Article
• Language: English
• Subjects: Adsorption; Agroindustrial waste; Corn husk; Methylene blue; Rice husk; Sugarcane bagasse
• ISSN: 2666-8939; 2666-8939
• DOI: 10.1016/j.carpta.2021.100061

•Three alkali pretreated agroindustrial wastes were characterized by SEM, chemical composition, ATR-FTIR, BET, XRD and pHzpc.•Cellulose was the main component of each alkali pretreated waste, 49 to 59 g 100 g−1.•The lignocellulosic biosorbents presented adsorption of MB higher than 90% from pH 3.0 to 11.0.•Quadratic models were obtained from Box-Behnken design with factors pH, dosage and concentration. Lignocellulosic residues of sugarcane bagasse (SCB), corn husk (CHW) and rice husk (RHW) were evaluated as renewable and low cost bioadsorbents of the methylene blue dye. Residues were treated with a 0.10 mol L−1 NaOH solution to remove part of the polymeric component of the fibers and to intensify the dye adsorption. They were characterized by chemical composition, SEM, ATR-FTIR, BET, XRD and pHzpc. The adsorbents were evaluated using the 23 full Box-Behnken design with the variables pH, dye concentration and adsorbent dosage, obtaining descriptive mathematical models for adsorption percentage and also the response surfaces. Cellulose, hemicellulose and lignin were the main constituents of the materials analyzed, totalizing 81 to 91 g 100 g −1, whose lignocellulosic groups were verified by ATR-FTIR. The wastes presented high percentage of adsorption: 95.7 ± 1.9 % for SCB, 98.5 ± 1.2 % for CHW and 95.4 ± 0.8 % for RHW at the central point of the experimental design. Therefore, alkali treatment provided an interesting alternative to produce efficient bioadsorbents from agroindustrial wastes. [Display omitted]