Calcium-Modified Siderite-Driven Optimization of Sulfur Autotrophic Denitrification Systems

Sulfur autotrophic denitrification is a promising new technology for the secondary treatment and effluent pollutant control of Sewage Treatment water treatment plants (WWTPS) , the microbial-driven denitrification process is coupled with the multi-element cycle of nitrogen, sulfur and iron. However, it is difficult for the existing technologies to effectively control the process of sulfur oxidation and acid production, and to achieve efficient removal of nitrogen and phosphorus in water with medium and high concentrations. In this study, a modified natural siderite coupled with sulfur autotrophic denitrification (SCAD) process was developed, which could be used for the treatment of wastewater containing heavy metals, by constructing a long-term (90-day) continuous flow contrast system of sulfur autotrophic denitrification (SAD) , sulfur-siderite coupled denitrification (SSAD) , and SCAD, the effects of sulfur autotrophic denitrification and SSAD were investigated, the superiority of SCAD in terms of nitrogen and phosphorus removal efficiency, sulfate formation inhibition and pH buffering capacity was systematically evaluated.