According to Avnimelech (2012), the use of a simple sugar, such
as glucose or molasses, results in fast removal of free ammonia,
while more complex carbohydrates require more time for degradation
to simple sugars, resulting in slower reduction of ammonia.
Therefore, it is possible that the degradation of the two sources of
organic material, molasses and feed, occurred at different rates in
MO treatments. Thus, the fast-absorbing carbon of the molasses
may not have been available for the formation of bacterial biomass
when the nitrogen of the feed was released. This hypothesis is reinforced
by the higher concentration of ammonia in the MO100 tanks.
On the other hand, in the RB treatments, the ammonia concentration
was low during the entire preparation phase. These results
suggest that the mixture of sources of easily absorbed organic matter
with those of a complex structure should be avoided since this
can result in higher ammonia levels in the water.