Study on the adsorption of methylene blue by NaOH KH550 modified bagasse

The chemical composition, thermal stability and crystallinity of NaOH/KH550 modified bagasse were studied using the infrared spectroscopic analysis, thermogravimetric analysis and X-ray diffractometry. After modification, the hemicellulose was removed and KH550 was grafted on the surface of the bagasse fibre effectively. Then, the modified bagasse was used as the adsorbent of methylene blue (MB) for the adsorption study. According to the results, the initial concentration of MB ranged from 10 to 200 mg/L at room temperature (25°C). And the removal rate of MB could reach 94% under the conditions of adsorbent dosage greater than or equal to 4 g/L, solution pH from 8 to 12 and an adsorption time longer than 60 minutes. Furthermore, the adsorption isotherm model and adsorption kinetic model of modified bagasse for MB were studied and the results showed that the adsorption isotherm accorded with Freundlich model and the adsorption kinetic model accorded with pseudo second-order kinetic equation.