Denitrification performance and microbial communities of solid-phase denitrifying reactors using novel composite

Abstract

This study explored the denitrification performance of solid-phase denitrification reactors packed with elemental sulfur/wheat straw/shell powder composites to treat nitrate-contaminated wastewater under different conditions. The sulfur-based autotrophic denitrification integrated natural-carbon-source (NCS)-based heterotrophic denitrification system was formed (SND). The fast start-up and intensified nitrogen removal performance were obtained in SND systems. The optimum denitrification performance was achieved by the SND15 reactor, with a maximum denitrification rate of 530 mg N·L-1·d-1 over 180 days operation. The co-existence of autotrophs and heterotrophs were observed in all reactors, this may contribute to better control of nitrogen in SND system. The outcomes provide a potential strategy of cost reduction to improve nitrogen removal of wastewater treatment plants (WWTPs) effluent.