Abstract

In conventional anaerobic digestion (AD) of livestock manure, temperature regulation faces an inherent paradox: thermophilic conditions facilitate pathogen inactivation but inhibit methanogenesis, whereas mesophilic conditions enable efficient methane production but are less effective at eliminating pathogens. This study systematically analyzed the methanogenic performance, microbial physiology, and the dynamics of biosafety factors during AD of chicken manure at 4 °C, 35 °C, and 55 °C. Additionally, a ceramic membrane (CM) coupled with ozone micro-nano bubbles (O3-MNBs) backwashing was configured for advanced digestate purification. Contrary to conventional understanding, mesophilic conditions (35 °C) simultaneously achieved optimal methanogenic efficiency (277.83 mL/gVS) and the efficient removal of viruses (66.65%) and antibiotic resistance genes (ARGs) (>77.11%), supported by a more diverse microbial community. While thermophilic conditions (55 °C) inactivated certain viruses, methanogenic efficiency was significantly inhibited by thermal stress. Moreover, the residual plasmid-borne ARGs were 3.04-fold higher than under mesophilic conditions. The integration of CM filtration with O3-MNBs backwashing effectively retained and inactivated pathogens while reducing the membrane fouling rate by 83.97%. The integration of mesophilic digestion, membrane filtration, and O3-MNBs processes synergistically achieved efficient energy recovery and robust pathogen control, providing technical support for the safe treatment and high-value resource utilization of manure.

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