GHG emissions from algal-bacterial granules

This study aimed to investigate N2O emission characteristics and its mitigation potential using photosynthetically reduced carbon dioxide (CO2). With increasing Chlorophyll-a contents (0-13.4 mg/g-MLVSS), N2O emission factors largely fluctuated within 0.4-3.0%, but uncorrelated with algae contents. The photosynthetically reduced CO2 emissions were positively correlated (R2=0.88) with Chlorophyll-a contents, and it can offset average N2O emissions (1.4%) when Chlorophyll-a achieved 11.1 mg/g-MLVSS. However, the algal-bacterial granules underwent disintegration twice due to decreasing CO2 availability, which indicated that Cyanobacteria-dominated granules can retain higher Chlorophyll-a content compared to Chlorophyta-dominated granules.