Estabilidade e desempenho de lodo granular aeróbio no tratamento de efluentes complexos

Abstract

In this study, the influence of certain operating conditions on aerobic granular sludge (AGS) sequencing batch reactors (SBR), the stability of granular biomass, and its efficiency in the treatment of complex wastewaters, was investigated. In a first study, it was observed that the storage time of granules directly influences their recovery period when returned to operating conditions prior to storage. In a second stage of the research, the efficiency of an AGS reactor in the co-treatment of synthetic wastewater and leachate in gradually increasing proportions of the first (1 to 10% volume/volume) was evaluated. It was observed that the sludge properties, in terms of settleability, improved with the leachate increment. Ammonium removal was around 100% for the leachate proportions 1, 2 and 5%. The addition of 1 and 2% of leachate provided high phosphate release and absorption, however, with 5 and 10%, the biodephosphatation activity was drastically affected. In a third stage of the thesis, the removal of Reactive azo dye 239 (RR239) by AGS was addressed. The results showed that the presence of azo dye did not affect granule structure and stability and the reactor was efficient to remove organic matter, ammonium and phosphorus, however, the degradation of the dye was very low. A posttreatment step using turnip peroxidase enzyme (Brassica rapa) allowed to achieve 70% removal of azo dye.