Abstract
Denitrification under high nitrate concentration was studied in a fed-batch mode. Methanol, sodium acetate and effluent from anaerobic digesters (AD) were compared as the carbon sources. An alternating oxy–anoxy regime (10 min aeration over a period of 110 min) seems to promote the establishment of denitrifying bio-flocks of good settling characteristics. The bio-flocks produced in an anoxic reactor were of inferior settling characteristics. Bio-flocks at concentrations of 4 to 5 g VSS/l denitrify efficiently on all three carbon sources tested. A maximum nitrate removal rate was found to be 0.486 g NO 3 −-N/(g VSS day). Nitrite accumulated initially but its concentration decreased with time and eventually reached zero when acetate or AD effluent were used as the carbon source.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have