Integrating stereo-elastic packing into ecological floating bed for enhanced denitrification in landscape water.

Abstract

The effects of stereo-elastic packing, as additional bio-carriers, on nitrogen removal in enhanced ecological floating beds (EFBs) are evaluated. Enhanced EFBs with additional stereo-elastic packing was demonstrated to enhance maximum TN removal efficiency (65.8%) over that of EFBs with plant and ceramisite only (54.9%). Performance enhancement was attributable to a 40.6% increase in sediment N accretion and intensification of denitrification by biomass on other carriers in the presence of stereo-elastic packing. Nonetheless, nitrogen uptake by plants was inhibited slightly. Stereo-elastic packing intensified denitrification rates on plant roots and ceramisite by increasing the attached biomass and enhancing the biomass activity, albeit to different extents. The increase in denitrification rate on plant root by 25.7% was significantly higher than that of 4.6% on ceramisite via increased NO2-N removal. Moreover, bacterial diversity on the carriers was significantly altered, and the enrichment of genera such as Aridibacter, Hyphomicrobium and Gemmobacter promoted denitrification processes.