REMOÇÃO DE NITROGÊNIO AMONIACAL E FÓSFORO DE ESGOTO SANITÁRIO EM BIORREATOR À MEMBRANA COM LEITO MÓVEL IRATI, PR

Abstract

This study evaluated the removal efficiency of ammoniacal nitrogen (NH4 +) and phosphorus (PO4 3) during operation of a moving bed membrane bioreactor (MBR) for wastewater treatment. The experimental system was operated in sequential batches in four different strategies, E1, E2, E3 and E4, in which the order of the aerobic and anaerobic phases and the presence or absence of the moving bed varied. The concentration of total suspended solids (TSS) in the MBR mixed liquor was controlled between 2 g L-1 and 4 g L-1. The average removal efficiency of NH4 +-N was 82.8%, and the E1 strategy had better performance reaching 93.4% removal. In this strategy, the aerobic stage precedes the anaerobic stage and the moving bed was present. The statistical analysis showed that the order of the aerobic and anaerobic stages influences meaningfully in the removal efficiency of NH4 +-N with p-value of 0.000278. The E4 strategy, operated without the moving bed and with the aerobic stage followed by anaerobic, obtained the best denitrification values, the average efficiency was 90.7%, without addition of external carbon source. The average removal efficiency of PO4 3-P was 61.2% for its soluble form and 57% for total PO4 3-P, and there was no statistically significant difference in the means of phosphorus removal rates from one strategy to another. There was no variation in the concentration of PO4 3--P in the mixed liquor during the aerobic and anaerobic stages, therefore the main mechanism phosphorus removal was not biological, but physical by the selectivity of the membranes.