Mitigation of nitrous oxide ( N2O) emission from swine wastewater treatment in an aerobic bioreactor packed with carbon fibers.

Mitigation of nitrous oxide ( N2O) emission from swine wastewater treatment was demonstrated in an aerobic bioreactor packed with carbon fibers ( CF reactor). The CF reactor had a demonstrated advantage in mitigating N2O emission and avoiding NOx ( NO3 + NO2) accumulation. The N2O emission factor was 0.0003 g N2O- N/ gTN-load in the CF bioreactor compared to 0.03 g N2O- N/ gTN-load in an activated sludge reactor ( AS reactor). N2O and CH4 emissions from the CF reactor were 42 g- CO2 eq/m3/day, while those from the AS reactor were 725 g- CO2 eq/m3/day. The dissolved inorganic nitrogen ( DIN) in the CF reactor removed an average of 156 mg/L of the NH4- N, and accumulated an average of 14 mg/L of the NO3- N. In contrast, the DIN in the AS reactor removed an average 144 mg/L of the NH4- N and accumulated an average 183 mg/L of the NO3- N. NO2- N was almost undetectable in both reactors. [ABSTRACT FROM AUTHOR]