Simultaneous bisphenol F degradation, heterotrophic nitrification and aerobic denitrification by a bacterial consortium

BACKGROUND: Traditional aerobic autotrophic nitrification and anoxic heterotrophic denitrification have many limitations. Recently, the simultaneous heterotrophic nitrification–aerobic denitrification (HN-AD) process has received increasing attention. Thus, the possibility of the simultaneous removal of bisphenols and NH₄ ⁺-N via HN-AD was investigated. RESULTS: A bisphenols-degrading bacterial consortium was enriched and capable of degrading 50 mg L⁻¹ bisphenol A, 300 mg L⁻¹ 4,4-dihydroxybenzophenone, 375 mg L⁻¹ bisphenol F (BPF) and 10 mg L⁻¹ bis(4-hydroxyphenyl)sulfide under aerobic conditions. Further studies showed that the bacterial consortium could completely degrade 300 mg L⁻¹ BPF and remove NH₄ ⁺-N at 35 °C with 150 rpm at the C/N ratio of over 10. Moreover, BPF mineralization and NH₄ ⁺-N reduction to N₂ were observed. Clone library analysis indicated that Salmonella enterica, Enterobacter,Citrobacter and Pseudomonas could cooperate to degrade BPF and reduce NH₄ ⁺-N to N₂. Among these species, the isolated Pseudomonas sp. HS-2 was capable of simultaneous BPF degradation and NH₄ ⁺-N removal via HN-AD. CONCLUSION: The experimental results demonstrated that the enriched bacterial consortium and the isolated strain HS-2 could simultaneously remove BPF and NH₄ ⁺-N via HN-AD, indicating that this is a potential way for the treatment of wastewaters containing these compounds.