Nitrous oxide from integrated fixed-film activated sludge membrane bioreactor: Assessing the influence of operational variables
- Autori: Mannina, G.; Capodici, M.; Cosenza, A.; Di Trapani, D.
- Anno di pubblicazione: 2018
- Tipologia: Articolo in rivista (Articolo in rivista)
The influence of the main operational variables on N2O emissions from an Integrated Fixed Film Activated Sludge University of Cape Town membrane Bioreactor pilot plant was studied. Nine operational cycles (total duration: 340 days) were investigated by varying the value of the mixed liquor sludge retention time (SRT) (Cycles 1â3), the feeding ratio between carbon and nitrogen (C/N) (Cycles 4â6) and simultaneously the hydraulic retention time (HRT) and the SRT (Cycles 7â9). Results show a huge variability of the N2O concentration in liquid and off-gas samples (ranged from 10â1Î¼g N2O-N Lâ1to 103Î¼g N2O-N Lâ1). The maximum N2O concentration (1228 Î¼g N2O-N Lâ1) in the off-gas samples occurred in the anoxic reactor at the lowest C/N value confirming that unbalanced C/N promotes the N2O emission during denitrification. The aerated reactors (aerobic and MBR) have been the major N2O emitters during all the three Phases.