Effects of optimized lignocellulosic pretreatment derivatives on hydrolysis efficiency and codigestion performance of corn straw with food waste

Corn straw is a typical lignocellulosic biomass, and its anaerobic conversion is generally limited by the hydrolysis limitation. Ozone pretreatment can effectively improve the biodegradability of straw; however, its key process parameters have not been systematically optimized or comprehensively verified for practical applications. In this study, single-factor experiments were conducted to determine suitable ranges of ozone dosage, pretreatment time, and solid-liquid ratio based on hydrolysis efficiency, followed by response surface optimization using biogas production as the response. The optimal ozone pretreatment conditions were determined to be ozone dosage of 0.30 mg O 3 /g CS, pretreatment time of 89.5 min, and solid-liquid ratio of 41.8 mg/mL. Anaerobic digestion performance under these conditions was subsequently evaluated in terms of methane yield, changes in corn straw physicochemical properties, pretreatment derivatives, and microbial community composition. Under these conditions, the cumulative methane yield increased by 85.71% compared with that of untreated corn straw. Ozone pretreatment also generated soluble intermediates, including furfural, 5-methylfurfural, and phenol. However, their concentrations remained within biologically tolerable levels, and no apparent inhibition of the methanogenic archaea Methanobacterium and Methanosarcina was observed. These findings demonstrate that the sequential screening and response surface optimization strategy can substantially improve the anaerobic conversion and methane recovery of corn straw. Moreover, the resulting soluble organic compounds may serve as transformable substrates rather than inhibitors during anaerobic digestion.