scholarly journals Enhanced nitrogen removal and energy saving in a microalgal–bacterial consortium treating real municipal wastewater

2018 ◽  
Vol 78 (1) ◽  
pp. 174-182 ◽  
Author(s):  
P. Foladori ◽  
S. Petrini ◽  
M. Nessenzia ◽  
G. Andreottola
Keyword(s):  
Energy Saving ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Heterotrophic Bacteria ◽  
Bacterial Consortium ◽  
Nitrification Rate ◽  
Specific Rate ◽  
Dark Phase ◽  
Total Nitrogen Removal

Abstract The optimization of total nitrogen removal from municipal wastewater was investigated in a laboratory-scale photo-sequencing batch reactor (PSBR) operated with a mixed microalgal–bacterial consortium spontaneously acclimatized to real wastewater. No external aeration was provided in the PSBR to reduce energy consumption: oxygen was only supplied by the microalgal photosynthesis. The enhancement of total nitrogen removal was achieved through: (1) feeding of wastewater in the dark phase to provide readily biodegradable COD when oxygen was not produced, promoting denitrification; (2) intermittent use of the mixer to favor simultaneous nitrification–denitrification inside the dense flocs and to achieve 41% energy saving with respect to continuous mixing. Efficient COD removal (86 ± 2%) was observed, obtaining average effluent concentrations of 37 mg/L and 22 mg/L of total COD and soluble COD, respectively. TKN removal was 97 ± 3%, with an average effluent concentration of 0.5 ± 0.7 mg NH4+-N/L. Assimilation of nitrogen by heterotrophic bacteria accounted only for 20% of TKN removal, whilst the major part of TKN was nitrified. In particular, the nitrification rate was 1.9 mgN L−1 h−1 (specific rate 2.4 mgN gTSS−1 h−1), measured with dissolved oxygen near zero, when the oxygen demand was higher than the oxygen produced by photosynthesis. Total nitrogen of 6.3 ± 4.4 mgN/L was measured in the effluent after PSBR optimization.

Intermittent feeding of wastewater in combination with alternating aeration for complete denitrification and control of filaments

2010 ◽  
Vol 61 (9) ◽  
pp. 2259-2266 ◽  
Author(s):  
Styliani Kantartzi ◽  
Paraschos Melidis ◽  
Alexander Aivasidis
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Anoxic Conditions ◽  
Total Nitrogen Removal

In the present study, a laboratory scale system, consisting of a primary settling tank, a continuous stirred tank reactor and a clarifier were constructed and operated, using wastewater from the municipal wastewater treatment plant in Xanthi, Greece. The system operated under intermittent aeration in aerobic/anoxic conditions and feeding of the wastewater once in every cycle. The unit was inoculated with sludge, which originated from the recirculation stream of the local wastewater treatment plant. The wastewater was processed with hydraulic retention time (HRT) of 12 h, in which various experimental states were studied regarding the combination of aerobic and anoxic intervals. The wastewater was fed in limited time once in every cycle of aerobic/anoxic conditions at the beginning of the anoxic period. The two states that exhibited highest performance in nitrification and total nitrogen removal were, then, repeated with HRT of 10 h. The results show that, regarding the nitrification stage and the organic load removal, the intermittent system achieved optimum efficiency, with an overall removal of biological oxygen demand (BOD5) and ammonium nitrogen in the range of 93–96% and 91–95% respectively. As far as the total nitrogen removal is concerned, and if the stage of the denitrification is taken into account, the performance of the intermittent system surpassed other methods, as it is shown by the total Kjeldahl nitrogen (TKN) removal efficiency of 85–87%. These operating conditions suppressed the growth of filamentous organisms, a fact reflected at the SVI values, which were lower than 150 ml/g.

The characteristics of nitrogen removal by the biofilter system

2000 ◽  
Vol 42 (12) ◽  
pp. 137-147 ◽  
Author(s):  
C.F. Ouyang ◽  
R.J. Chiou ◽  
C.T. Lin
Keyword(s):  
Biological Activity ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Bulk Solution ◽  
Hydraulic Loading ◽  
Recycle Ratio ◽  
Total Nitrogen Removal ◽  
Set Up

Previous research has shown that nitrogen from municipal wastewater could be eliminated by a biofilter system. In this study a system of combined pre-denitrification/nitrification biofilters was set up. It is to investigate the effect of the hydraulic loading and recycled ratio on nitrogen removal. The characteristics of bacterial activity at different heights is discussed. The experiment shows that longer hydraulic loading would result in better total nitrogen removal. Total nitrogen removal might be not dependent on denitrification but nitrification. Hydraulic loading that affects nitrification might be due to the diffusion of NH3–N from the bulk solution to the inner biofilm. The recycling NO3–N could be completely eliminated in the anoxic biofilter. The operation with longer retention time (HRT of 12 hours) would result in inner denitrification in the aerobic biofilter. Biological activity could be determined by the distribution of bacteria. The specific rates of pollutant decomposition depend on biological activity and effective biological VSS. The effect of the recycled ratio on the nitrogen removal is significant. Total nitrogen removal rate and nitrogen type of effluent would be determined by recycle ratio. The operation at low recycled ratio would result in worse total nitrogen removal, but the NH3–N of effluent would be lower. The operation in higher recycle ratio would be opposite to low recycle ratio.

scholarly journals Modeling granule-based completely autotrophic nitrogen removal over the nitrite (CANON) process in an SBR

2021 ◽  
Author(s):  
Qing Cai ◽  
Qiang He ◽  
Sheng Zhang ◽  
Jiajia Ding
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Ammonia Oxidation ◽  
Heterotrophic Bacteria ◽  
Removal Rate ◽  
Operation Condition ◽  
N Concentration ◽  
Heterotrophic Microorganisms ◽  
Simulation Results ◽  
Total Nitrogen Removal

Abstract Based on the simplified activated sludge model No. 1 (ASM1), a 1D biofilm model containing autotrophic microorganisms and heterotrophic microorganisms was developed to describe the microbial population dynamics and reactor dynamics of CANON SBR. After sensitivity analysis and calibration for parameters, the simulation results of NH4+-N concentration and NO2−-N concentration were consistent with the measured results, while the simulated NO3−-N concentration was slightly lower than the measured. The simulation results showed that the soluble microbial products had an extremely low concentration. The aerobic ammonia oxidation bacteria and anaerobic ammonia oxidation bacteria were the dominant microbial populations of the CANON system, while nitrite oxidization bacteria and heterotrophic bacteria were eliminated completely. The optimal ratio of air aeration load to influent NH4+-N load was about 0.18 L air/mgN. The operation condition of the reactor was optimized according to the simulation results, and the total nitrogen removal rate and the total nitrogen removal efficiency increased from 0.312 ± 0.015 to 0.485 ± 0.013 kg N/m3/d and from 71.2 ± 4.3 to 85.7 ± 1.4%, respectively.

Pilot-Scale Testing of the Hybrid Membrane Biofilm Process (HMBP) for Total Nitrogen Removal from Municipal Wastewater

2008 ◽  
Vol 2008 (9) ◽  
pp. 6236-6244 ◽  
Author(s):  
Leon S. Downing ◽  
Kyle Bibby ◽  
Kathleen Esposito ◽  
Thomas Fascianella ◽  
Robert Nerenberg
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Hybrid Membrane ◽  
Total Nitrogen Removal ◽  
Biofilm Process

Effects of tetracycline on simultaneous biological wastewater nitrogen and phosphorus removal

RSC Advances ◽  
2015 ◽  
Vol 5 (73) ◽  
pp. 59326-59334 ◽  
Author(s):  
A. Chen ◽  
Y. Chen ◽  
C. Ding ◽  
H. Liang ◽  
B. Yang
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Protective Role ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Total Nitrogen Removal

The presence of 2 and 5 mg L−1of tetracycline decreased total nitrogen removal. Tetracycline induced EPS release and decreased its protective role on cells. Denitrifiers instead of nitrifiers were negatively affected by tetracycline.

scholarly journals Upflow packed bed Anammox reactor used in two-stage deammonification of sludge digester effluent

2018 ◽  
Vol 78 (9) ◽  
pp. 1843-1851 ◽  
Author(s):  
İ. Çelen-Erdem ◽  
E. S. Kurt ◽  
B. Bozçelik ◽  
B. Çallı
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Packed Bed ◽  
Municipal Wastewater Treatment ◽  
Two Stage ◽  
N Removal ◽  
Total Nitrogen Removal

Abstract The sludge digester effluent taken from a full scale municipal wastewater treatment plant (WWTP) in Istanbul, Turkey, was successfully deammonified using a laboratory scale two-stage partial nitritation (PN)/Anammox (A) process and a maximum nitrogen removal rate of 1.02 kg N/m3/d was achieved. In the PN reactor, 56.8 ± 4% of the influent NH4-N was oxidized to NO2-N and the effluent nitrate concentration was kept below 1 mg/L with 0.5–0.7 mg/L of dissolved oxygen and pH of 7.12 ± 12 at 24 ± 4°C. The effluent of the PN reactor was fed to an upflow packed bed Anammox reactor where high removal efficiency was achieved with NO2-N:NH4-N and NO3-N:NH4-N ratios of 1.32 ± 0.19:1 and 0.22 ± 0.10:1, respectively. The results show that NH4-N removal efficiency up to 98.7 ± 2.4% and total nitrogen removal of 87.7 ± 6.5% were achieved.

Total nitrogen removal from high-strength ammonia recycle stream using a single submerged attached growth bioreactor

2007 ◽  
Vol 55 (8-9) ◽  
pp. 59-65 ◽  
Author(s):  
A. Onnis-Hayden ◽  
P.B. Pedros ◽  
J. Reade
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Treatment Plant ◽  
High Strength ◽  
Nitrogen Loading ◽  
Digested Sludge ◽  
Attached Growth ◽  
Anaerobically Digested Sludge ◽  
Total Nitrogen Removal

An experimental study investigating the nitrogen removal efficiency from the recycle stream generated in the dewatering facility of the anaerobically digested sludge at the Deer Island wastewater treatment plant (WWTP) in Boston was conducted using a single submerged attached growth bioreactor (SAGB), designed for simultaneous nitrification and denitrification. The applied nitrogen loading to the reactor ranged from 0.7 to 2.27 kg-N/m3·d, and the corresponding total nitrogen (TN) removal rate ranged from 0.38 to 1.8 kg-N/m3·d. The observed nitrification rates varied from 0.42 kg-N/m3·d to 1.45 kg-N/m3·d with an ammonia load of 0.5 kg-N/m3·d and 1.8 kg-N/m3·d, respectively. An average nitrification efficiency of 91% was achieved throughout the experiment. Denitrification efficiency varied from 55%, obtained without any addition of carbon source, to 95% when methanol was added in order to obtain a methanol/nitrate ratio of about 3 kg methanol/kg NO3−-N.

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