Mechanisms of genuine humic acid evolution and its dynamic interaction with methane production in anaerobic digestion processes

Humic acid (HA), a byproduct formed during the biological conversion of organic matter into biogas in anaerobic digestion (AD) process, contains complex structures and redox functions. However, evolution mechanism HA its interaction with CH4 production AD process have not been fully explored, particularly respect to various substrates temperature conditions. In this study, we investigated evolutionary dynamics structure function genuine that naturally processes chicken manure corn stover under mesophilic (37 °C) thermophilic (55 The results demonstrated mechanisms different pathways. core showed higher degree aromaticity (41.2–66.7% 45.3–68.4% for respectively) humification index (1.5–4.2 2.8–4.5 than those (28.3–45.3% 30.2–54.5% 0.6–1.2 1.3–3.7 index) manure. from HSQC NMR spectroscopy 2D-COS-FTIR an accelerating effect on through humification. Moreover, concurrent decomposition re-polymerization both processes, resulting positive negative effects fast slow stages, respectively. dynamic was due variations electron transferring ability HA. could only advance our understanding performance but also support further research toward improving by regulating formation transformation.