Nitrogen Removal from Wastewater Using Sequencing Batch Reactors

摘要

The removal of nitrogenous impurities from wastewater to a gaseous nitrogen form requires the coordinated coupling of two bio-mechanisms, nitrification and denitrification. Nitrification is an aerobic process conducted by autotrophic, nitrifying bacteria. Denitrification by select heterotrophic bacterial species requires anoxic conditions and a readily available electron donor. As a hybrid of the fill-and-draw configuration, a Sequencing Batch Reactor (SBR) system provides a repetitive cycling of varied environments conducive to the performance of such nitrogen-linked bacterial species. Aerobic and anoxic periods can be controlled to promote the activity of the nitrifying and denitrifying bacteria. Bench-scale SBR studies using a synthetic, high-strength waste stream achieved a consistent 99+% organic carbon removal and 92+% nitrogen removal. Observed specific substrate utilization rates for both nitrification and denitrification were in excess of values typically associated with conventional activated sludge systems.