Title:
Inhibitory Effect of Free Nitrous Acid on Short-Cut Nitrification Treating Methanogenic-Treated Incineration Leachate by Sequencing Batch Reactor
Author(s):
Liu, X., Dang, Y., Sun, D.
Document(s):
Paper
Poster
Abstract:
Anaerobically treated leachate from municipal solid waste incineration plants contains extremely high ammonia concentrations (1200~1600 mg/L NH4+-N). The nitrogen removal process treated by short-cut nitrification/denitrification produced a high level free nitrous acid(FNA)which can hinder short-cut nitrification processes. In order to develop strategies that will help overcome this limitation, thresholds of FNA inhibition on ammonia oxidation (nitritation) were identified in laboratory-scale sequencing batch reactors, which was ~0.1 mg/L for nitritation. pH adjustments made during the nitritation process kept FNA concentrations below 0.1 mg/L, enabling reactors to operate when total ammonia nitrogen (TAN) concentrations were 1400 mg/Lwith 1000~1200 mg/L nitrite produced at the end of nitritation. Reactors without pH adjustment, on the other hand, deteriorated after a period of operation.Heterotrophic ammonia oxidizing bacteria were predominant members (70%) of the microbial community found in the pH-adjusted reactor. The majority of metabolically active heterotrophic nitrifiers clustered with the genus Paracoccus (~90%), while all of the autotrophic nitrifiers were Nitrosomonas species.Quantitative reverse transcription (qRT) PCR was done on RNA extracted from the pH-adjusted reactor operated at TAN concentrations of 1400 mg/L and exposed to various concentrations of FNA (0.018, 0.103, 0.195, and 0.328 mg/L).The results showed that transcription of heterotrophicamoA genes was significantly inhibited by elevated FNA concentrations, while the number of autotrophic amoA mRNA transcripts was positively correlated with FNA concentrations.
Keywords:
incineration leachate, FNA inhibition threshold, autotrophic nitrifier, heterotrophic nitrifier, amoA gene transcript, short-cut nitrification
Topic:
Biomass Resources
Subtopic:
Municipal and industrial wastes
Event:
26th European Biomass Conference and Exhibition
Session:
1AV.2.7
Pages:
143 - 148
ISBN:
978-88-89407-18-9
Paper DOI:
10.5071/26thEUBCE2018-1AV.2.7
Price:
FREE
