nitrifying microorganisms. The biomass growth, in turn, was
greater on top of the
first layer of sand (Rodgers et al., 2005) than
on the others. Furthermore, the intermittent application of influent
plays an important role in the bed’s aeration and boosts the growth
of nitrifying bacteria (Bahgat et al., 1999). This characteristic favors
the transformation of organic nitrogen and ammonia into nitrate.