Rimozione combinata di carbonio e nutrienti in due reattori SBR con differente fango granulare

Abstract

Performances of two sequencing batch reactor (SBR), fed with acetate-based synthetic wastewater and working with different aerobic granular sludge, in terms of mean granule sizes, were studied. In particular, the present study investigates the impact of different granule sizes on the Simultaneous Nitrification Denitrification (SND) process, as well as on biological phosphorous removal. Different strategies of cultivation and several organic (COD 600-1200mg/L) and nitrogen( 60-120 mg/L) loading rate have been applied, in order to evaluate the efficiencies in SND process without control of dissolved oxygen. Despite several authors report that a low oxygen concentration is required for N-removal optimization, results show that even under conditions of high oxygen concentration nutrients and organic matter can be satisfactorily removed. Further, the data show that the biological conditions in the inner layer of the granule (aerobic, anoxic and anaerobic) change between small and big granules during the feast and famine periods.