Nitritation versus Full Nitrification of Ammonium-Rich Wastewater: Comparison in terms of Nitrous and Nitric Oxides Emissions. wastewater metagenome

Two lab-scale sequencing batch reactors (SBR1 and SBR2) were inoculated with activated sludge from a local domestic wastewater treatment plant (WWTP) located in Girona (Spain). SBR1 was fed with synthetic wastewater containing 1 g NH4+-N/L, in order to promote the growth of ammonia oxidizing bacteria (AOB). SBR2 was fed with synthetic wastewater which comprised 1g NO2--N/L and nitrite oxidizing bacteria (NOB) growth was enhanced. In order to achieve full nitrification of synthetic wastewater (1 g NH4+-N/L), 50% of the bacterial population (~0.4 gVSS/L) in SBR1 was substituted with the same amount of biomass extracted from SBR2, resulting in a mixed AOB/NOB community (~0.8 gVSS/L).