Biogas production and synergistic correlations of systematic parameters during batch anaerobic digestion of corn straw.

Abstract Although many studies have been done about anaerobic digestion of corn straw, the insight of process performance focusing on biogas production and systematic parameters still needs to be further investigated. This paper investigated biogas production, synergistic correlations of systematic parameters and their correlations based on the effects of total solid (TS) content and initial pH on the digestion performance of corn straw. Results demonstrated that biogas production was significantly correlated with systematic parameters, and the best digestion performance was found at TS content of 4% and initial pH 7.5. Furthermore, the ratio of inoculum to substrate (I/S) should be an indicator for forecasting process performance. The significant synergistic correlations of each kind parameter were also achieved. Moreover, three different synergistic effect pathways of I/S, pH, volatile fatty acid (VFA), hydrolysis rate (k), biogas production potential (P), the maximum biogas production rate (R max) and lag phase (λ) were concluded: (1) I/S→pH (R2 = 0.841, P < 0.01)→k (R2 = 0.831, P < 0.01)→R max (R2 = 0.818, P < 0.01), (2) I/S→pH (R2 = 0.841, P < 0.01)→P (R2 = 0.920, P < 0.01) and (3) I/S→VFA (R2 = −948, P < 0.01)→λ (R2 = −0.662, P < 0.05). Taken together, this report will be a basis for further study of industrial anaerobic digestion of corn straw. Highlights • TS content of 4% with initial pH 7.5 could be an appropriate adjusting measure. • I/S and VS were the main operating parameters influencing other parameters. • The significant synergistic correlations of each kind parameter were achieved. • Three different synergistic effect pathways of these parameters were concluded. [ABSTRACT FROM AUTHOR]