Aerobic granules to treat wastewater containing methylene blue (MB) were successfully developed in a sequencing batch reactor (SBR) using activated sludge as inoculum. After cultivation for 87 days, stable aerobic granules were obtained with a clearly defined shape and a diameters ranging from 2 to 4 mm. After granulation, the removal efficiencies of MB and chemical oxygen demand (COD) reached 56% and 93%, respectively. Specific MB biodegradation rates followed the Haldane model and the associated kinetic parameters were as follows: V-max = 184.15 mg L-1 h(-1), K-s = 209.96 mg L-1, and K-i = 21.23 mg L-1. The aerobic granules proved to be a feasible and effective way to degrade MB-containing wastewater. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.