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.

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.

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.

Efficient and integrated start-up strategy for partial nitrification to nitrite treating low C/N domestic wastewater

2009 ◽  
Vol 60 (12) ◽  
pp. 3243-3251 ◽  
Author(s):  
Jianhua Guo ◽  
Shuying Wang ◽  
Huijun Huang ◽  
Yongzhen Peng ◽  
Shijian Ge ◽  
...  
Keyword(s):  
Domestic Wastewater ◽  
Kinetic Mechanism ◽  
Partial Nitrification ◽  
Nitrifying Bacteria ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Start Up ◽  
Operation Results

Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.

Combining partial nitritation and heterotrophic denitritation for the treatment of landfill leachate previous to an anammox reactor

2010 ◽  
Vol 61 (8) ◽  
pp. 1949-1955 ◽  
Author(s):  
R. Ganigué ◽  
J. Gabarró ◽  
H. López ◽  
M. Ruscalleda ◽  
M. D. Balaguer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Total Nitrogen ◽  
Landfill Leachate ◽  
Nitrous Acid ◽  
Process Performance ◽  
Free Nitrous Acid ◽  
Partial Nitritation ◽  
Feed Strategy ◽  
The Stability ◽  
Conventional Systems

Landfill leachate can present extremely elevated concentrations of ammonium (up to 6,000 mg N-NH4+ L−1) and a low biodegradable organic matter fraction. As an alternative to conventional systems, this wastewater can be treated on a more sustainable way by a fully autotrophic partial nitritation–anammox system. The operation of the first step of this system, the partial nitritation, is critical since the elevated concentrations of ammonium and nitrite in the reactor can severely inhibit ammonium oxidizing bacteria (AOB) activity. In this way, the inclusion of anoxic phases during the feeding events to promote the denitrification via nitrite can be a good option for upgrading the process performance and increasing the stability of the system. This paper deals with the evaluation of an anoxic–aerobic step-feed strategy for the operation of a partial nitritation SBR. Results of this study have revealed a decrease on the total nitrogen inside the reactor of more than 200 mg N L−1 without prejudice on the partial nitritation process. Furthermore, this study has also allowed detecting an AOB activity reduction at the end of aerobic phases due to bicarbonate limitation and/or free nitrous acid inhibition.

Tailoring of highly efficient nitrifying biofilms in fluidized bed for ammonia-rich industrial wastewater treatment

2000 ◽  
Vol 42 (3-4) ◽  
pp. 357-362 ◽  
Author(s):  
S. Tsuneda ◽  
T. Miyoshi ◽  
Y. Aoi ◽  
A. Hirata
Keyword(s):  
Fluidized Bed ◽  
Industrial Wastewater ◽  
Domestic Wastewater ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Fish Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
High Concentration ◽  
Stepwise Reduction ◽  
Biofilm Structure

We proposed two tailoring methods for efficient nitrifying biofilms on particles which are expected to be used in fluidized bed in nitrogen removal processes for industrial wastewaters. The first method was examined with gradual reduction of the hydraulic retention time in continuous feeding reactor to form biofilm with high nitrification ability. As a result, nitrification rate was successfully improved mainly due to acclimation of nitrifying bacteria to higher loading. The second tailoring method for nitrifying biofilm started with the biofilm which had been previously constructed in synthetic domestic wastewater containing high concentration of NH4+-N as well as various biodegradable organic compounds. Stepwise reduction of C/N ratio in inlet wastewater was performed during one month simultaneously with observation of microbial population dynamics in the biofilm using fluorescent in situ hybridization (FISH) analysis. As a result, this acclimation process promoted occupation of the biofilm by ammonia-oxidizing bacteria and resulted in making suitable biofilm structure for nitrification of ammonia-rich industrial wastewater. Moreover, it is confirmed that this new tailoring method greatly shortened required time to obtain nitrifying biofilms.

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