Short‐Cut Nitrification–Denitrification Spatial Combination Technology for Treating High‐Concentration Nitrogen‐Containing Wastewater: Influence of pH and Carbon Source

ABSTRACT Short‐cut nitrification (SCN) and denitrification (DN) technology is an efficient method for treating high‐concentration nitrogen‐containing wastewater. However, controlling the reaction conditions in single‐reactor systems is difficult. In this study, SCN and DN were performed in separate reactors to investigate the influence of pH on SCN and the effect of carbon sources on DN. The results revealed that a combination of SCN and DN achieved a total nitrogen removal efficiency of 84%. Within a specific pH range (6.5–9.0), the accumulation of nitrite during SCN exhibited an initial increase, followed by a decrease, reaching a maximum at pH 8.5. In addition, this study established two experimental groups to investigate the effect of carbon sources on DN. The blank group (without the addition of a carbon source) exhibited a chemical oxygen demand (COD) concentration of 5.1 mg/L, whereas the control group (sodium acetate used as the carbon source) exhibited a COD concentration of 118.6 mg/L. These results indicate a substantial improvement in DN efficiency with the addition of a carbon source. The integrated approach of short‐cut nitrification and denitrification results in a total nitrogen removal efficiency of 84%. Throughout the pH spectrum of 6.5–9.0, nitrite accumulation in the short‐cut nitrification process initially rises, then falls, peaking at a pH of 8.5. Additionally, introducing a carbon source significantly enhances the efficiency of denitrification.