The Inhibitory Effect of Free Nitrous Acid and Free Ammonia on the Anoxic Phosphorus Uptake Rate of Polyphosphate-Accumulating Organisms
Dimitris Andreadakis,
Constantinos Noutsopoulos,
Daniel Mamais,
Vera Charalambous,
Asimina Koukoura,
Simos Malamis
Affiliations
Dimitris Andreadakis
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
Constantinos Noutsopoulos
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
Daniel Mamais
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
Vera Charalambous
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
Asimina Koukoura
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
Simos Malamis
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, 15780 Athens, Greece
The purpose of this study is to investigate the effect of free nitrous acid (FNA) and free ammonia (FA) on the anoxic phosphorus uptake rate (PUR) of polyphosphate-accumulating organisms (PAOs) via the utilization of nitrite. With this goal, upon developing a PAO-enriched culture in a sequential batch reactor, a series of batch experiments were conducted to examine the effects of nitrite and ammonium on the anoxic phosphorus uptake rate at different pH levels. According to the results, both free nitrous acid and free ammonia were found to inhibit anoxic PUR to a degree similar to their respective effects on aerobic PUR reported in previous studies, suggesting that phosphorus removal via the anoxic pathway may be just as susceptible as that via the aerobic pathway. The effect of FNA on anoxic PUR is optimally described by a non-competitive inhibition model with a KiFNA value of 1.6 μg N L−1, while the Levenspiel model with an SFA* value of 37 mg N L−1 provided the best fit for the FA effect on PAOs anoxic activities. The results of this study provide new insights regarding the viability of EBPR under high nitrogen loading conditions.
