Denitrifying sulfide removal process on high-salinity wastewaters

Denitrifying sulfide removal (DSR) process comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide, and acetate into nitrogen gas, elemental sulfur (S0), and carbon dioxide, respectively. Sulfide- and nitrate-laden wastewaters at 2–35 g/L NaCl were treated by DSR process. A C/N ratio of 3:1 was proposed to maintain high S0 conversion rate. The granular sludge with a compact structure and smooth outer surface was formed. The microbial communities of DSR consortium via high-throughput sequencing method suggested that salinity shifts the predominating heterotrophic denitrifiers at <10 g/L NaCl to autotrophic denitrifiers at >10 g/L NaCl.