Valorization of sugarcane bagasse for sugar extraction and residue as an adsorbent for pollutant removal.

Abstract

Following juice crushing for sugar or bioethanol production from sugarcane, bagasse (SCB) is generated as the main lignocellulosic by-product. This study utilized SCB generated by a hydraulic press as feedstock to evaluate sugar extraction as well as adsorption potential. Total soluble sugar (sucrose, glucose, and fructose) of 0.4 g/g SCB was recovered with H2O extraction in this case. Insoluble sugar, that is, cellulose in SCB, was further hydrolyzed into glucose (2%–31%) with cellulase enzyme, generating a new bagasse residue (SCBE). Persulfate pretreatment of SCB slightly enhanced saccharification. Both SCB and SCBE showed great potential as adsorbents with 98% of methylene blue (MB) removed by SCB or SCBE and 75% of Cu2+ by SCBE and 80% by SCB in 60 min. The maximum adsorption amount (q m) was 85.8 mg/g (MB by SCB), 77.5 mg/g (MB by SCBE), 3.4 mg/g (Cu2+ by SCB), and 1.2 mg/g (Cu2+ by SCBE). The thermodynamics indicated that the adsorption process is spontaneous, endothermic, and more random in nature. The experimental results offer an alternative to better reutilize SCB.