Free ammonia and free nitrous acid inhibition on the anabolic and catabolic processes of Nitrosomonas and Nitrobacter

2007 ◽  
Vol 56 (7) ◽  
pp. 89-97 ◽  
Author(s):  
V.M. Vadivelu ◽  
J. Keller ◽  
Z. Yuan
Keyword(s):  
Nitrous Acid ◽  
Energy Production ◽  
Inhibitory Effect ◽  
Free Ammonia ◽  
Fish Analysis ◽  
Batch Reactors ◽  
Inhibitory Effects ◽  
Free Nitrous Acid ◽  
Production Capability ◽  
Batch Tests

The inhibitory effects of free ammonia (FA) and free nitrous acid (FNA) on the catabolic and anabolic processes of Nitrosomonas and Nitrobacter were investigated using a method that allows decoupling the growth and energy generation processes. Lab-scale sequencing batch reactors (SBRs) were operated for the enrichment of Nitrosomonas and Nitrobacter. Fluorescent In-Situ Hybridization (FISH) analysis showed that the reactors were 82% and 73% enriched with Nitrosomonas and Nitrobacter, respectively. Batch tests were carried out to measure the oxygen uptake rate (OUR) by the enriched cultures at various FA and FNA levels, in the presence (OURwithCO2) or absence (OURwithoutCO2) of inorganic carbon (CO2, HCO3− and CO32−). FA up to 16.0 mgNH3-N.L−1 was not found to have any inhibitory effect on either the catabolic or anabolic processes of the Nitrosomonas culture, but both these processes were inhibited by FNA. While an FNA level of 0.40–0.63 mgHNO2-N.L−1 inhibited the energy production capability of Nitrosomonas by 50%, the growth process of the culture was completely inhibited by FNA at a concentration of 0.40 mgHNO2-N.L−1. Both FA and FNA were found to have strong inhibition on the anabolic processes of Nitrobacter, but with limited inhibitory effects on the catabolism of this culture. The biosynthesis of Nitrobacter was totally inhibited at an FA level of 6.0 mgNH3-N.L−1 (or above) or an FNA level of 0.02 mgHNO2-N.L−1 (or above). At the same level of FA, the energy production capability of Nitrobacter was only inhibited by 12%, whereas an FNA level of up to 0.024 mgHNO2-N.L−1 did not show any inhibition on the energy production of Nitrobacter. Further, these inhibitory effects appears to be much stronger on Nitrobacter than on Nitrosomonas, supporting that FA and FNA inhibition may play a major role in the elimination of nitrite oxidizing bacteria in processes treating wastewater containing a high level of nitrogen.

Achieving nitrogen removal via nitrite pathway from urban landfill leachate using the synergetic inhibition of free ammonia and free nitrous acid on nitrifying bacteria activity

2013 ◽  
Vol 68 (9) ◽  
pp. 2035-2041 ◽  
Author(s):  
H. W. Sun ◽  
Y. Bai ◽  
Y. Z. Peng ◽  
H. G. Xie ◽  
X. N. Shi
Keyword(s):  
Landfill Leachate ◽  
Biological System ◽  
Nitrous Acid ◽  
Free Ammonia ◽  
Nitrifying Bacteria ◽  
Anaerobic Sludge ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
Free Nitrous Acid

In this study, a biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic–oxic (A/O) reactor was established for the advanced treatment of high ammonium urban landfill leachate. The inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on the nitrifying bacterial activity was used to achieve stable nitritation in the A/O reactor. The results demonstrated that the biological system achieved chemical oxygen demand (COD), total nitrogen (TN) and NH4+-N removal efficiencies of 95.3, 84.6 and 99.2%, respectively at a low carbon-to-nitrogen ratio of 3:1. Simultaneous denitritation and methanogenesis in the UASB could improve the removal of COD and TN. Nitritation with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Fluorescence in situ hybridization (FISH) analysis showed that ammonia oxidizing bacteria (AOB) was dominant and was considered to be responsible for the satisfactory nitritation performance.

scholarly journals Effect of Free Ammonia, Free Nitrous Acid, and Alkalinity on the Partial Nitrification of Pretreated Pig Slurry, Using an Alternating Oxic/Anoxic SBR

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Marisol Belmonte ◽  
Chia-Fang Hsieh ◽  
José Luis Campos ◽  
Lorna Guerrero ◽  
Ramón Méndez ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Batch Reactor ◽  
Inhibitory Effect ◽  
Free Ammonia ◽  
Partial Nitrification ◽  
Total Alkalinity ◽  
Pig Slurry ◽  
Solid Retention Time ◽  
Free Nitrous Acid ◽  
Nitrite Oxidizing Bacteria

The effect of free ammonia (NH3or FA), free nitrous acid (HNO2or FNA), and total alkalinity (TA) on the performance of a partial nitrification (PN) sequencing batch reactor (SBR) treating anaerobically pretreated pig slurry was studied. The SBR was operated under alternating oxic/anoxic (O/A) conditions and was fed during anoxic phases. This strategy allowed using organic matter to partially remove nitrite (NO2-) and nitrate (NO3-) generated during oxic phases. The desiredNH4+toNO2-ratio of 1.3 g N/g N was obtained when an Ammonium Loading Rate (ALR) of 0.09 gNH4+-N/L·d was applied. The system was operated at a solid retention time (SRT) of 15–20 d and dissolved oxygen (DO) levels higher than 3 mg O2/L during the whole operational period. PN mainly occurred caused by the inhibitory effect of FNA on nitrite oxidizing bacteria (NOB). Once HNO2concentration was negligible,NH4+was fully oxidized toNO3-in spite of the presence of FA. The use of biomass acclimated to ammonium as inoculum avoided a possible effect of FA on NOB activity.

Biological Treatment of High Ammonium Content Urban Landfill Leachate Using an Anaerobic-Aerobic Process

2013 ◽  
Vol 781-784 ◽  
pp. 2095-2099
Author(s):  
Hong Wei Sun ◽  
Yong Jun You ◽  
Ying Guo
Keyword(s):  
Landfill Leachate ◽  
Inhibitory Effect ◽  
Nitrifying Bacteria ◽  
Anaerobic Sludge ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Free Nitrous Acid ◽  
Nitrite Oxidizing Bacteria ◽  
Anaerobic Sludge Blanket

Biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor was applied to treat high ammonium content urban landfill leachate. Inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on nitrifying bacteria activity was used to achieve nitrogen removal via nitrite pathway in the A/O. Results demonstrated that removed efficiencies of COD, total nitrogen (TN) and NH4+-N were 95.3%, 84.6 %and 99.2%, respectively. Stable nitrite pathway with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Moreover, Fluorescence in situ hybridization (FISH) analysis showed that AOB was dominant microorganism.

Could nitrite/free nitrous acid favour GAOs over PAOs in enhanced biological phosphorus removal systems?

2011 ◽  
Vol 63 (2) ◽  
pp. 345-351 ◽  
Author(s):  
M. Pijuan ◽  
L. Ye ◽  
Z. Yuan
Keyword(s):  
Phosphorus Removal ◽  
Nitrous Acid ◽  
Wastewater Treatment Plants ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Inhibitory Effects ◽  
Nitrogen Gas ◽  
Free Nitrous Acid ◽  
Polyphosphate Accumulating Organisms ◽  
Biological Phosphorus

Enhanced biological phosphorus removal (EBPR) normally occurs together with nitrogen removal in wastewater treatment plants (WWTPs). In recent years, efforts have been devoted to remove nitrogen via the nitrite pathway (oxidation of ammonia to nitrite and reduction of nitrite to nitrogen gas without going through nitrate), reducing the requirement for carbon and oxygen in the plant. However nitrite and free nitrous acid (FNA), the protonated species of nitrite, have been shown to cause EBPR deterioration under certain concentrations. This study provides a direct comparison between the different levels of FNA inhibition in the aerobic processes of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) by reviewing the studies published in this area. Also, new data is presented assessing the FNA effect on the anaerobic metabolism of these two groups of bacteria. Overall, FNA has shown inhibitory effects on most of the processes involved in the metabolism of PAOs and GAOs. However, the inhibition-initiation levels are different between different processes and, even more importantly between the two groups. In general, PAOs appear to be more affected than GAOs at the same level of FNA, thus giving GAOs competitive advantage over PAOs in EBPR systems when nitrite is present.

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