Higher efficiency of vanadate iron in heterogeneous Fenton-like systems to pretreat sugarcane bagasse and its enzymatic saccharification.

Pretreatment is crucial for effective enzymatic saccharification of lignocellulose such as sugarcane bagasse (SCB). In the present study, SCB was pretreated with five kinds of heterogeneous Fenton-like systems (HFSs), respectively, in which α-FeOOH, α-FeO, FeO, and FeS worked as four traditional heterogeneous Fenton-like catalysts (HFCs), while FeVO worked as a novel HFC. The enzymatic reducing sugar conversion rate was then compared among SCB after different heterogeneous Fenton-like pretreatments (HFPs), and the optimal HFS and pretreatment conditions were determined. The mechanism underlying the difference in saccharification efficiency was elucidated by analyzing the composition and morphology of SCB. Moreover, the ion dissolution characteristics, variation of pH and Eh values, HO and hydroxyl radical (·OH) concentration of FeVO and α-FeO HFSs were compared. The results revealed that the sugar conversion rate of SCB pretreated with FeVO HFS reached up to 58.25%, which was obviously higher than that under other HFPs. In addition, the surface morphology and composition of the pretreated SCB with FeVO HFS were more conducive to enzymatic saccharification. Compared with α-FeO, FeVO could utilize HO more efficiently, since the dissolved Fe and V can both react with HO to produce more ·OH, resulting in a higher hemicellulose and lignin removal rate and a higher enzymatic sugar conversion rate. It can be concluded that FeVO HFP is a promising approach for lignocellulose pretreatment.