Figure 3: Temporal profile of a steady-state cycle (8 h) in condition 1, in terms of: (a) concentrations of nitrogen compounds: (▲) NH4+-N; (◊) NH3-N; (○) NO3--N; (●) NO2--N; and (b) (▲) DO concentration with the respective (■) DO/NH3 and (□) DO/NH4+ ratios.