Regarding nitrogen, the plant was able to remove
87.5 5.3% of TKN with a residual concentration in the
effluent of 4.9 2.4 mg/l, indicating that a stable nitrification
process was established, with average concentrations of oxidised
nitrogen in the effluent of 7.6 4.5 mg/l, contrary to
what usually detected in biological systems treating textile
wastewater, where the nitrifying biomass activity is usually
reduced because of the many textile inhibitory compounds
(Rozzi et al., 1999; Bortone et al., 1997