Short CommunicationPretreatment of rice straw by ultrasound-assisted Fenton process

- Fenton's reagent can preferentially degrade hemicellulose and lignin.
- Ultrasound can degrade cellulose, hemicellulose and lignin simultaneously.
- Both ultrasound and Fenton's reagent can increase the surface area of rice straw.
- The highest concentration of reducing sugar was obtained from the U/F-RS.

Fenton's reagent, ultrasound, and the combination of Fenton's reagent and ultrasound were used to pretreat rice straw (RS) to increase its enzymatic digestibility for saccharification. The characterization shows that compared with ultrasound, Fenton's reagent pretreatment was more efficient in increasing the specific surface area and decreasing the degree of polymerization (DP) of RS. The enzymatic hydrolysis results showed that the RS pretreated by ultrasound-assisted Fenton's reagent (U/F-RS), which exhibited the largest specific surface area and the lowest DP value, had the highest enzymatic activity, and the amount of reducing sugar released from U/F-RS at 48 h of enzymatic saccharification is about 4 times as large as that from raw RS and 1.5 times as large as that from Fenton's reagent pretreated RS. The ultrasound-assisted Fenton process provides a reliable and effective method for RS pretreatment.