Aplicação da tecnologia do lodo granular aeróbio no tratamento de esgoto doméstico em Fortaleza-CE

Abstract

Aerobic granular sludge technology has shown promise for sewage treatment considering its good performance in the removal of organic matter and nutrients. Despite several laboratoryscale research, there are still few studies reporting the application of pilot and real-scale technology. The present work aimed to develop aerobic granules from domestic sewage in a pilot reactor operated in sequencing batch reactor, evaluating biomass stability and performance in the removal of organic matter and nutrients. In addition, water production for reuse was also evaluated. The research was conducted at the EPC, operated by CAGECE and lasted 225 days. Although the influent used presented variations and low organic load (COD 461 mg / L), it was observed that the formed granules had good characteristics (IVL30 <70mL / g) and remained stable, without disintegration of biomass. The granulation process was completed in less than 2 months and about 60% of the granules in the reactor had a diameter greater than 1 mm. The granular biomass had a compact structure, smooth surface and yellowish-gray coloration. The average performance after reactor optimization was 95.2%, 97.4% and 88.5% in the removal of COD, NH4 + and P-PO43-, respectively. Finally it was observed that the treated effluent, after sand filter polishing, provided a high quality reuse water (Turbidity <1UT, COD <30 mg / L; SST <20 mg / L). Considering the characteristics of Fortaleza-CE domestic sewage and the local climatic condition, it was observed that it is possible to cultivate and maintain aerobic granules in RBS during long periods of operation.