Robertson,W.D., Moore,T.A., Spoelstra,J., Li,L., Elgood,R.J., Clark,I.D., Schiff,S.L., Aravena,R. and Neufeld,J.D.(2012): Natural attenuation of septic system nitrogen by anammox. Ground Water, 50(4), 541-553.

『嫌気性アンモニア酸化による腐敗システム窒素の自然減衰』


Abstract
 On-site disposal of sewage in septic systems can lead to groundwater plumes with NO3--N concentrations exceeding the common drinking water limit of 10 mg/L. Currently, denitrification is considered as the principal natural attenuation process. However, at a large seasonal-use septic system in Ontario (256 campsites), a suboxic zone exists where nitrogen removal of up to 80% occurs including removal of NH4+-N. This zone has both NO3--N and NH4+-N at >5 mg/L each. In the distal NH4+-rich zone, NH4+-N concentrations (8.1±8.0 mg/L) are lower than in the proximal zone (48±36 mg/L) and NH4+-N is isotopically enriched (concentration-weighted mean δ15N of +15.7‰) compared to the proximal zone (+7.8‰). Furthermore, δ15N-NH4+ isotopic enrichment increases with depth in the distal zone, which is opposite to what would result if nitrification along the water table zone was the mechanism causing NH4+ depletion. Bacterial community composition was assessed with molecular (DNA-based) analysis and demonstrated that groundwater bacterial populations were predominantly composed of bacteria from two Candidatus genera of the Planctomycetales (Brocasia and Jettenia). Together, these data provide strong evidence that anaerobic ammonium oxidation (anammox) plays an important role in nitrogen attenuation at this site.』

Introduction
 Long Point site
Methods
Results
 Ammonium and nitrate distribution
 Microbiology
Discussion
 NH4+ breakthrough
 NH4+ isotopic behavior
 Mechanisms of NH4+ degradation
 Anammox reaction rate
 Anammox bacteria
Conclusion and implications
Acknowledgments
Supporting information
References


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