Aerobic granular sludge - A case report

Aerobic granular sludge was observed in a Sequencing Batch Reactor (SBR) in which a synthetic urban wastewater containing sodium acetate as an organic substrate was fed, and dissolved oxygen (DO) was controlled at low concent ration (0.7-1.0 mg/l) Microscope examination showed that the morphology of the granules was nearly spherical (0.3-0.5 mm in diameter) with a very clea r outline, The granular sludge had a good settleability (Sludge Volume Inde x (SVI) between 50-100 ml/g) and high COD removal and nitrification activit ies (2.16 g(TOC)/g(SS).d and 0.24 g(NH3-N)/g(SS).d). With granular sludge, high quality effluent was obtained for treatment of synthetic wastewater un der low DO. (C) 1998 Elsevier Science Ltd, All rights reserved.