Long-Term Operation of a Pilot-Scale Sulfur-Based Autotrophic Denitrification System for Deep Nitrogen Removal

Sulfur-based autotrophic denitrification is a novel biological process characterized by the absence of an organic carbon source, short reaction time, high rate, low treatment cost, and small footprint. However, technique facing challenges with respect to engineering applications. In this study, pilot-scale sulfur-based system was established optimal hydraulic retention time (HRT) 0.21 h, which achieved highest load 1158 mg/(L·d) rate 164 gNO3−-N/(m3·h). Effective backwashing basis for long-term stable efficient nitrogen removal performance, recovered its normal performance within 0.5 h. addition, operation cost merely 0.013 $/t, indicating that presents good economic applicability, relatively will lay foundation practical application.