In addition to the general advantages of the staged SBR technology, AGS systems present several unique attributes [13]:excellent settling properties, allowing shorter settling times for good solid–liquid separation and requiring lower construction area; good biomass retention, allowing higher concentration in the SBR and consequently lower reaction time and/or reactor volume; ability to withstand toxicity and high organic loading rates,making them attractive for industrial wastewater treatment applications; aerobic and anoxic/anaerobic zones within the granules,allowing organic matter, nitrogen and phosphorus removal in the same system and potentially contributing to the process of azo dyemineralization. Given the particular attributes of aerobic granules,this compact technology has a great potential for the treatment of the highly variable textile wastewaters, including the biodecolorization of textile dyes that are generally resistant to aerobic biodegradation, like azo dyes.