New operational strategy for SBR technology for total nitrogen removal from industrial wastewaters highly loaded with nitrogen

The present work deals with the upgrading of conventional Sequential Batch Reactor (SBR) technology for treating industrial wastewater. The aim is to obtain total nitrogen removal in a single SBR by implementing short aeration cycles. The operational strategy of conventional SBR consisting of a sequence of five phases (filling, aeration, stirring, settling and withdrawing) is simplified into a four phases sequence (filling, short cycled aeration, settling and withdrawing). This operational sequence has been proven to be adequate for total nitrogen removal from high strength wastewater containing nitrogen (up to 700 mg TKN/L) and organic matter (up to 2,000 mg COD/L). Short-cycled aeration allowed for a more efficient use of the oxygen supply for nitrification and the organic carbon content present in the wastewater for denitrification. The results here reported show that initially the tested technology is feasible and can report significant outs in operation and maintenance when compared with conventional SBR processes. Total nitrogen removal up to 79% was attained treating the effluent of an UASB process;designed for treating the wastewater of a potato starch factory. Total nitrogen removal capacities ranging between 0.2 and 0.65 kg of nitrogen per cubic metre per day are reported.