Dynamic Multi-Subunit Strategy Responding to Seasonal Temperature Variation in Sulfur Autotrophic Denitrification Bioreactor

Abstract

This study developed a comprehensive methodology for designing and operating an elemental sulfur autotrophic denitrification (S0AD) bioreactor, adeptly addressing seasonal temperature variation. Initially, the nitrate removal rate was correlated with the simulated real-site temperature and nitrate loading, unveiling the correlation coefficients of k1, k2, k3, and A as [[EQUATION]], -0.41, 0.04, and 0.13, respectively, to establish a mathematical model capable of predicting S0AD performance. Subsequently, integrating factors like dissolved oxygen influence and dynamic sulfur consumption, the model was deployed to meticulously engineer a pilot-scale S0AD bioreactor for application in a case study. Employing alternative multi-subunit operation, a stable effluent nitrate below 8 mg-N/L was achieved throughout the year. Of paramount significance, this strategy realized a substantial 76.8% reduction in excessive nitrate removal, sulfur consumption, and sulfate production. This study furnishes an optimum blueprint and operational strategy for the pragmatic utilization of S0AD bioreactors, thereby ensuring heightened dependability and cost-effectiveness.

Keywords: sulfur autotrophic denitrification, temperature, multi-subunit, prediction model, pilot scale