Fabrication of cellulose nanocrystal from Carex meyeriana Kunth and its application in the adsorption of methylene blue

Cellulose nanocrystal (CNC) was extracted from Carexmeyeriana Kunth (CMK) by a combination of TEMPO oxidation and mechanical homogenization method, and used to remove methylene blue (MB) from aqueous solution. After alkali-oxygen treatment, the aqueous biphasic system (polyethylene glycol/inorganic salt) was applied to further remove lignin from CMK. The characteriazation of CNC, and the effects of H2O2 dosage, CNC dosage, adsorption time, and initial MB concentration on the MB removal capacity of CNC were investigated. The results showed that the removal percentage of MB by CNC was raised with the increase of H2O2 and CNC dosage. The adsorption kinetics of prepared CNC followed the pseudo second-order model, and the adsorption isotherms fitted well to the Langmuir model with a calculated maximum adsoption capacity of 217.4 mg/g, which was higher than those of CNC extracted by acid hydrolysis method, indicating CNC extracted from CMK had promising potentials in the field of MB adsorption. (C) 2017 Elsevier Ltd. All rights reserved.