Enhancement of methane production by anaerobic digestion of corn straw with hydrogen-nanobubble water

Hydrogen-nanobubble water was proposed to enhance methane production by anaerobic digestion (AD) with corn straw. The effects of H-2-nanobubble water (H-2-NBW) amounts (0%, 20%, 40%, 60%, 80%, and 100%) on methane production characteristics of corn straw were explored. The results showed that the methane yields were increased by 11.54%similar to 25.29% compared with the control group(CK), and the maximum cumulative methane production reached to 254.36 mL.g-VS-1 when the H-2-NBW addition was of 60%. Interestingly, the maximum methane concentration increased by 4.37% compared with CK. H-2-NBW addition can destroy the cellulose structure of corn straw, reduce the crystallinity of cellulose, and promote the hydrolysis. The degradation rate of cellulose and hemicellulose were increased by 20%-33% and 13%similar to 25.7% respectively, and the removal rate of TS and VS were increased by 6.82%-27.93% and 8.52%-21.47%, respectively. The modified Gompertz equation fitted the cumulative methane production curves very well, with high correlation coefficients (R-2 > 0.992).

Automated summary

The addition of hydrogen-nanobubble water significantly increased methane production from corn straw, with a maximum yield of 254.36 mL·g-VS-1. The presence of H-2-NBW disrupted the cellulose structure, reduced crystallinity, and promoted hydrolysis.