It is thermodynamically possible that denitrification of NO2
-N
or NO3
-N can be achieved by using Mn as an electron donor. In
addition, the nitrate-reducing bacteria genera Hyphomicrobium
have also been observed to oxidize Mn in rapid sand filters for
the treatment of ground water (Vandenabeele et al., 1995). The
average influent Mn concentration was about 0.664 mg/L during
the two operational periods of phases II and III, as is shown in
Fig. 2. According to the equations provided by Vandenabeele