Methane Redirection for a Novel Biological Nitrogen Removal Process in a Sequential Batch Reactor System

Excess nutrients in wastewater discharge is leading to eutrophication of surface waters causing environmental harm. Wastewater treatment plants (WWTPs) are shifting towards water reuse and recovery facilities (WRRFs) to improve process sustainability while recovering higher value resources. Fortunately, methanotrophic bacteria can couple methane usage with nitrogen removal. This research investigates methane redirection for methanotrophic-based nitrogen removal enriched from activated sludge. Different phases allowed evaluation of the nitrogen removal capacity of the methanotrophic culture in a sequential batch reactor. This research is the first to maintain stable nitrate accumulation using methanotrophic cultures. The maintenance of nitrification-denitrification activity using the same culture found to be challenging. Advantageously, the methanotrophic culture enriched for nitrogen removal can be employed for biopolymer accumulation to further consolidate the WRRF concept. This study confirms the potential of using methanotrophic bacteria for stable nitrogen removal and biopolymer accumulation, however, further studies are still needed to improve process feasibility.