Effect of weak electrical stimulation on m-dichlorobenzene biodegradation in biotrickling filters: Insights from performance and microbial community analysis

The microbial electrolysis cell coupled with the biotrickling filters (MEC-BTF) was developed for enhancing the biodegradation of gaseous m -dichlorobenzene ( m -DCB) through weak electrical stimulation. The maximum removal efficiency and elimination capacity in MEC-BTF were 1.48 and 1.65 times higher than those in open-circuit BTF (OC-BTF), respectively. Weak electrical stimulation had a positive impact on the characteristics of the biofilm. Additionally, microbial community analysis revealed that weak electrical stimulation increased the abundance of key functional genera ( e . g ., Rhodanobacter and Bacillus ) and genes ( e . g ., catA/E and E1.3.1.32), thereby accelerating reductive dechlorination and ring-opening of m -DCB. Macrogenomic sequencing further revealed that electron transfer pathway in MEC-BTF might be mediated through extracellular electroactive mediators and cytochromes.