Effect and optimization of NaOH combined with Fenton pretreatment conditions on enzymatic hydrolysis of poplar sawdust

Abstract

In this study, the effects and mechanism of pretreatments of three types of chemical reagents combined with Fenton on poplar sawdust were studied and the optimization of enzymatic hydrolysis conditions was conducted using response surface methodology. The results showed that cellulase and hemicellulase had the best hydrolysis effect after NaOH-Fenton pretreatment, which were 63.73% and 29.29%, respectively. The optimal process of poplar substrate was to react in 1% NaOH at 100 ℃ for 1 h, then placed in the Fenton reaction system of 0.2 mmol Fe 2+ and 25 mmol H2O2 for 7 h, and finally subjected to enzymatic hydrolysis for 72 h at 52 ℃, with a liquid-solid ratio of 33 and 15 μL/g of β-glycosidase. Under this condition, the enzymatic hydrolysis rates of cellulase and hemicellulase reached 86.65% and 43.9%, respectively. In conclusion, the combination of NaOH and Fenton pretreatment can effectively promote the enzymatic hydrolysis of poplar sawdust, which has great potential in the production of cellulosic ethanol.