Effect of sequencing batch cycle strategy on the treatment of a simulated textile wastewater with aerobic granular sludge

Aerobic granular sludge was successfully developed on a simulated textile effluent with an added azo dye, on a non-tubular sequential batch reactor (SBR), with better granulation results than in a dye-free control SBR fed with the same base medium. The overall performance of the treatment was very good, with high color and chemical oxygen demand (COD) removal yields (up to 85% and 80%, respectively). Operation under two sequencing batch cycle strategies, i.e., with a single anaerobic/aerobic reaction phase or under intermittent aeration, showed that the latter generally improved the treatment performance. Under intermittent aeration, biomass accumulation was induced, with faster settling aggregates, leading to a higher COD removal yield. Although a lower decolorization rate was observed in the first 30 min of anaerobic reaction, as compared to the single phase strategy, the overall color removal remained high. This work demonstrates the applicability of the new aerobic granular sludge technology for the treatment of textile effluents. (C) 2015 Elsevier B.V. All rights reserved.