Full-scale activated sludge transplantation reveals a highly resilient community structure.

Well-functioning and stable microbial communities are critical for the operation of activated sludge (AS) wastewater treatment plants (WWTPs). Bioaugmentation represents a potentially useful approach to recover deteriorated systems or to support specific AS processes, but its application in full-scale WWTPs is generally problematic. We conducted a massive transplantation (in one day) exchanging AS from a donor to a recipient full-scale WWTP with similar process type (biological removal of nitrogen and phosphorus) and performance, but with differences in microbial community structure.

Challenges in carbon footprint evaluations of state-of-the-art municipal wastewater resource recovery facilities.

Wastewater treatment is an important source of direct and indirect greenhouse gas (GHG) emissions, which some wastewater operators report and account for CO-eq impacts through carbon footprint evaluations. We investigated the challenges with GHG emissions' accounting of three state-of-the-art energy-efficient wastewater resource recovery facilities (WRRFs) and reviewed their CO accounting reports. Our study aimed to highlight the major contributors and factors to estimate emissions, including direct NO and CH emissions and propose recommendations for public reporting of CO accounting of WRRFs.