Sequencing batch reactor technology for biological wastewater treatment: a review

Wastewater treatment has been a challenge throughout the years due to varying influent characteristics and stringent effluent regulations. In response to this dilemma, a reliable, cost-effective and high-efficiency sequencing batch reactor (SBR) technology has been recently developed. SBRs are variations of the activated sludge process that operates on a fill-and-draw basis. It combines both aerobic-anaerobic phases in one unit and saves up to 25% of the aeration costs concomitant with low sludge production. Consequently, simultaneous nitrogen and phosphorus removal from the wastewater could be achieved by adjusting the actual operating cycle. This review paper discusses the technical description and operational flexibility of SBR for the treatment of wide range of effluent under different operational conditions, together with its modifications that could increase the effectiveness of SBR systems in the future. (C) 2010 Curtin University of Technology and John Wiley & Sons, Ltd.