Elemental sulfur-based autotrophic denitriflcation and denitritation: microbially catalyzed sulfur hydrolysis and nitrogen conversions

摘要

The hydrolysis of elemental sulfur (S0) coupled to S0-based denitrification and denitritation was investigated in batch bioassays by microbiological and modeling approaches. In the denitrification experiments, the highest obtained NO3−-N removal rate was 20.9 mg/l·d. In the experiments with the biomass enriched on NO2−, a NO2−-N removal rate of 10.7 mg/l·d was achieved even at a NO2−-N concentration as high as 240 mg/l. TheHelicobacteraceaefamily was only observed in the biofilm attached onto the chemically-synthesized S0particles with a relative abundance up to 37.1%, suggesting it was the hydrolytic biomass capable of S0solubilization in the novel surface-based model. S0-driven denitrification was modeled as a two-step process in order to explicitly account for the sequential reduction of NO3−to NO2−and then to N2by denitrifying bacteria.