Bioaugmentation with Acinetobacter sp. TAC-1 to enhance nitrogen removal in swine wastewater by moving bed biofilm reactor inoculated with bacteria

To enhance the performance of moving bed biofilm reactor (MBBR) inoculated with heterotrophic nitrification aerobic denitrification (HN-AD) bacteria, bioaugmentation with Acinetobacter sp. TAC-1 was firstly employed and then the treatment performance for real swine wastewater was presented in this study. Results indicated that NH4+-N and TN removal rates of bioaugmented reactor were significantly improved from 16.53 mg/L/h and 16.15 mg/L/h to 24.58 mg/L/h and 24.45 mg/L/h, respectively. The efficient removal performance (NH4+-N 95.01%, TN 86.40%) for real swine wastewater was achieved within 24 h. Microbial analysis indicated that the composition of functional bacteria varied with the introduction of Acinetobacter sp. TAC-1, especially the abundance of Acinetobacter, Paracoccus and Rhodococcus related to the nitrogen removal. Furthermore, bioaugmentation with Acinetobacter sp. TAC-1 increased abundance of enzymes and functional genes (nirS, nirK and norZ) corresponding to denitrification that may be responsible for the enhanced nitrogen removal performance.

Automated summary

In this study, bioaugmentation with Acinetobacter sp. TAC-1 was employed to enhance the treatment performance of a moving bed biofilm reactor (MBBR) inoculated with heterotrophic nitrification aerobic denitrification (HN-AD) bacteria. The results showed that the removal rates of NH4+-N and TN in the bioaugmented reactor were significantly improved. The efficient removal performance for real swine wastewater was achieved within 24 hours. Microbial analysis revealed changes in the composition of functional bacteria and an increase in the abundance of enzymes and functional genes related to denitrification.