Biorreator à membrana em batelada sequencial aplicado ao tratamento de esgoto visando à remo？？o de nutrientes

this study evaluated the performance of a membrane bioreactor sequencing batch, in pilot scale, to remove nutrients (nitrogen and phosphorus) from domestic wastewater. the reactor was operated for 241 days with a total cycle time of 4 hours, with 5 minutes for feeding, 55 minutes for the anoxic phase and 180 minutes for the aeration and filtration phases (simultaneously). throughout the monitoring, two filtration flows were employed: 5.5 and 11.1 (critical flux) l.m-2.h-1, which resulted in the volume exchange rates of 5 and 10%, respectively. the removal efficiencies of total chemical oxygen demand, ammonia nitrogen and total nitrogen were achieved by 99, 98 and 96%, respectively. regarding phosphorus removal, a poor performance was observed in the beginning of the experiment; however, a tendency of improvement in the removal of this nutrient was further verified, reaching an efficiency average of 74% between the operational days 158 and 241. the flux filtration at 5.55 l.m-2.h-1 has provided a membrane bioreactor sequencing batch stable operation in relation to transmembrane pressure since it reached the limit value of 0.7 bar only once in 181 operational days, while for 11.1 l.m-2.h-1 it was observed 3 times in 55 days.