Niche Compartmentalization Promotes Dissolved Methane Removal and Simultaneous Nitrification and Denitrification in a...

Area of Science:

• Environmental Engineering
• Microbiology
• Biotechnology

Background:

• Anaerobic effluents contain dissolved methane and ammonium, requiring efficient removal.
• Greenhouse gas emissions and nitrogen pollution are significant environmental concerns.
• Hybrid reactors offer potential for simultaneous pollutant removal.

Purpose of the Study:

• To evaluate a hybrid membrane aerated biofilm reactor (MABR) for removing dissolved methane and ammonium.
• To understand the microbial communities and their spatial arrangement in the hybrid MABR.
• To assess the efficiency of methane and nitrogen removal in treated wastewater.

Main Methods:

• Long-term reactor operation and in situ batch tests.
• 16S rRNA gene amplicon sequencing for microbial community analysis.
• Metaproteomics and 15N tracer experiments for mechanistic insights.

Main Results:

• Confirmed coexistence of methane-oxidizing, nitrifying, and denitrifying bacteria.
• Achieved 99% dissolved methane removal and 90% ammonium removal at steady-state.
• Demonstrated 65% total nitrogen removal, with evidence of nitrosation/nitrifier-denitrification.

Conclusions:

• Hybrid MABR is effective for simultaneous removal of methane and nitrogen pollutants.
• Microbial consortia in MABR play a key role in pollutant degradation.
• Findings support strategies for mitigating greenhouse gas emissions and nitrogen pollution in reclaimed water.