Efficient dye removal using manganese oxide-modified nanocellulosic films from sugarcane bagasse

Removing toxic dyes from industrial wastewater is crucial for environmental protection. This research introduced novel composite films of manganese oxide (MnO₂)-modified nanocellulose (MCel) and unmodified nanocellulose (Cel) derived from sugarcane bagasse for dye removal. Nanocellulose was extracted from sugarcane bagasse and subsequently transformed into MCel through in-situ MnO₂ synthesis. The MCel/Cel composites, with various MCel to Cel ratios, were fabricated into films and evaluated for their efficiency in removing methylene blue (MB). The films were characterized using Fourier transform infrared spectroscopy for functional group analysis, X-ray diffraction for crystallinity, X-ray photoelectron spectroscopy for chemical state analysis, field emission scanning electron microscopy-energy dispersive spectroscopy for morphology and elemental composition, and Thermogravimetric Analysis for thermal behaviors. Adsorption results showed that all MCel/Cel composite films achieved over 97 % removal of MB (initial concentration 100 mg L^-1) within 24 h, with convenient adsorbent retrieval after adsorption. The adsorption process followed a pseudo-second order kinetic model and Langmuir adsorption isotherm. The optimal 95:5 MCel/Cel film exhibited a rate constant of 6.16 × 10^-4 g mg^-1 min^-1 and the calculated adsorption capacity of 181.85 mg g^-1. These results demonstrate significant potential for wastewater treatment and sustainable waste valorization by converting sugarcane bagasse cellulose into environmentally friendly adsorbents for contaminant removal.