scholarly journals Impact of Free Ammonia and Free Nitrous Acid on Nitritation in Membrane Aerated Bioreactors Fed with High Strength Nitrogen Urine Dominated Wastewater

2021 ◽  
pp. 107001
Author(s):  
Maryam Salehi Pourbavarsad ◽  
Behnaz Jalili Jalalieh ◽  
Nick Landes ◽  
W. Andrew Jackson
Keyword(s):  
Nitrous Acid ◽  
High Strength ◽  
Free Ammonia ◽  
Free Nitrous Acid

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.

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.

Inhibition effect of free ammonia and free nitrous acid on nitrite-oxidising bacteria during sludge liquor treatment: influence of feeding strategy

2014 ◽  
Vol 68 (7) ◽  
Author(s):  
Pavel Svehla ◽  
Jan Bartacek ◽  
Lukas Pacek ◽  
Helena Hrncirova ◽  
Josef Radechovsky ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Feeding Strategy ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Free Ammonia ◽  
Reactor Operation ◽  
High Concentration ◽  
Free Nitrous Acid ◽  
Operation Regime ◽  
Inhibition Effect

AbstractThe importance of feeding strategy for the long-term selective inhibition of nitrite-oxidising bacteria (NOB) was demonstrated by comparison of laboratory-scale bioreactors: Completely Stirred Tank Reactor (CSTR) and Sequencing Batch Reactor (SBR). Moreover, the effect of the change of reactor operation regime from CSTR to SBR was demonstrated. Sludge liquor containing ammonia nitrogen in a range of 970–1500 mg L−1 was the influent of the reactors. The experiments were performed at (23 ± 2)°C, with high concentration of dissolved oxygen (up to 8 mg L−1) and with unlimited sludge retention time. In the SBR, permanent restriction of NOB activity was achieved for more than 700 days by the strong inhibition effect of fluctuating concentrations of free ammonia and free nitrous acid during the operational cycles of SBR. In contrast, nitrite-oxidising bacteria were able to gradually adapt to the conditions prevailing in CSTR and produce nitrate although the concentration of free ammonia and free nitrous acid significantly exceeded inhibition limits for NOB activity in this system. Transferring the reactor operation regime from CSTR to SBR resulted in immediate and permanent inhibition of NOB activity in the reactor.

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