Effect of Fenton pretreatment combined with bacteria inoculation on humic substances formation during lignocellulosic biomass composting derived from rice straw.

The goal of this work was to explore the effect of Fenton pretreatment combined with bacteria inoculation on the formation of humic substances (HS) during rice straw composting. In this study, the compound bacterial agents were inoculated after Fenton pretreatment during rice straw composting. The results suggested that the coupling effects of Fenton pretreatment and bacteria inoculation promoted the humification process, which might be the reason of organic fractions degradation and transformation. In addition, the bacterial communities structure and diversity were changed by Fenton pretreatment and inoculation. Key microbial genera linking to the transformation of organic fractions were determined by network analysis. Redundancy analysis and structural equation model analysis indicated that Fenton pretreatment, inoculation, amino acid, soluble sugar and beta-diversity as the key factors affecting organic fractions transformation during composting. Therefore, the combined application Fenton pretreatment with bacteria inoculation provided a new method to promote the HS amount.