Anaerobic digestion (AD) is a crucial process for treating wastewater and producing methane, but the widespread antibiotic ciprofloxacin (CIP) often disrupts it. CIP, commonly found in wastewater, inhibits the growth of key bacteria needed for methanogenesis. To address this challenge, a recent study explored the addition of biochar (BC), made from corn stover, to enhance AD performance under CIP stress.

The research found that adding BC increased methane production by up to 2.6 times, with CIP degradation efficiency improving to 96.6%. Biochar acted through several mechanisms, including reducing oxidative stress, stabilizing microbial communities, and facilitating direct electron transfer between microbes involved in methane production.

By enriching bacteria like Methanosaeta and Syntrophomonas, BC promoted more efficient methanogenesis. It also reduced the production of toxic intermediates during CIP degradation, protecting the anaerobic system. Genetic analysis showed that BC upregulated genes related to both CIP breakdown and methane production.

This study demonstrates that biochar can play a significant role in mitigating the negative effects of antibiotics on anaerobic digestion, offering a promising solution for improving wastewater treatment efficiency while enhancing methane recovery.