Electron transfer rates and energy releases during denitrification of municipal waste water

摘要

This paper presents the results of studies on denitrification of municipal wastewater in the bulk water phase under conditions of excess electron acceptor and excess electron donor. Experiments conducted on 13 wastewater samples have shown that the denitrification process in the bulk water phase could be simplified by a two-stage process. In the first stage, nitrate was utilised with significant accumulation of nitrite. In the second stage nitrite was utilised when nitrate is depleted. Denitrification rates during the two stages were expressed in terms of electron equivalents (e-eq.) in order to compare the process when different electron acceptors, namely, nitrate and nitrite were utilised. The energy release rates during the two stages were calculated and compared.