Rapid start-up and enhancement of simultaneous nitrification-denitrification phosphorus removal granular sludge

In order to explore the rapid start-up of simultaneous nitrification-denitrification phosphorus removal granular sludge system, this study first cultivated sludge granulation through starvation-repletion and gradually shortened sedimentation time. By regularly adding 30 mg/L NO2--N, a high concentration of nitrite environment was provided to enhance nitrogen and phosphorus removal. The nitrogen load of the system was further increased to examine its nitrogen and phosphorus removal efficiency. The system achieved rapid sludge granulation after 28 days of cultivation, with MLSS stabilized at 5.6—6.2g/L and SVI30/SVI5 reaching 0.96, indicating good particle settling performance. Through nitrite enhancement, the anaerobic phosphorus release of the system increased from 3.51mg/L to 29.4mg/L, while NOB activity was inhibited, achieving short-cut nitrification-denitrification phosphorus removal. Under the condition of C/N/P=420/80/10(w/w/w), the system achieved 99.85% total nitrogen removal and 99.43% phosphorus removal. Microbial community analysis revealed that the genus Acinetobacter predominated under this initiation strategy © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.