scholarly journals Modelling shortcut nitrogen removal from wastewater using an algal–bacterial consortium

2016 ◽  
Vol 75 (4) ◽  
pp. 782-792 ◽  
Author(s):  
Larissa T. Arashiro ◽  
Angelica M. Rada-Ariza ◽  
Meng Wang ◽  
Peter van der Steen ◽  
Sarina J. Ergas
Keyword(s):  
Nitrogen Removal ◽  
Biogas Production ◽  
Inorganic Nitrogen ◽  
Light Attenuation ◽  
Holistic Approach ◽  
Bacterial Consortium ◽  
Volume Index ◽  
Ammonium Concentration ◽  
Light Cycle ◽  
Shortcut Nitrogen Removal

A shortcut nitrogen removal process was investigated for treatment of high ammonium strength wastewater using an algal–bacterial consortium in photo-sequencing batch reactors (PSBRs). In this process, algae provide oxygen for nitritation during the light period, while denitritation takes place during the dark (anoxic) period, reducing overall energy and chemical requirements. Two PSBRs were operated at different solids retention times (SRTs) and fed with a high ammonium concentration wastewater (264 mg NH4+-N L−1), with a ‘12 hour on, 12 hour off’ light cycle, and an average surface light intensity of 84 μmol m−2 s−1. High total inorganic nitrogen removal efficiencies (∼95%) and good biomass settleability (sludge volume index 53–58 mL g−1) were observed in both PSBRs. Higher biomass density was observed at higher SRT, resulting in greater light attenuation and less oxygen production. A mathematical model was developed to describe the algal–bacterial interactions, which was based on Activated Sludge Model No. 3, modified to include algal processes. Model predictions fit the experimental data well. This research also proposes an innovative holistic approach to water and energy recovery. Wastewater can be effectively treated in an anaerobic digester, generating energy from biogas, and later post-treated using an algal–bacterial PSBR, which produces biomass for additional biogas production by co-digestion.

scholarly journals Biological Nitrogen Removal in a Photosequencing Batch Reactor with an Algal-Nitrifying Bacterial Consortium and Anammox Granules

2016 ◽  
Vol 3 (4) ◽  
pp. 175-179 ◽  
Author(s):  
Nathan D. Manser ◽  
Meng Wang ◽  
Sarina J. Ergas ◽  
James R. Mihelcic ◽  
Arnold Mulder ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Batch Reactor ◽  
Bacterial Consortium ◽  
Biological Nitrogen Removal ◽  
Biological Nitrogen

scholarly journals Nitrification–denitrification in waste stabilisation ponds: a mechanism for permanent nitrogen removal in maturation ponds

2010 ◽  
Vol 61 (5) ◽  
pp. 1137-1146 ◽  
Author(s):  
M. A. Camargo Valero ◽  
L. F. Read ◽  
D. D. Mara ◽  
R. J. Newton ◽  
T. P. Curtis ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Isotope Analysis ◽  
Pilot Scale ◽  
Intermediate Step ◽  
Nitrogen Transformations ◽  
Waste Stabilisation Ponds ◽  
Molecular Microbiology ◽  
Denitrification Process ◽  
Ammonia Oxidising Bacteria

A pilot-scale primary maturation pond was spiked with 15N-labelled ammonia (15NH4Cl) and 15N-labelled nitrite (Na15NO2), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of δ15N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity.

Enhancement of polycyclic aromatic hydrocarbons removal during anaerobic treatment of urban sludge

2003 ◽  
Vol 48 (4) ◽  
pp. 53-60 ◽  
Author(s):  
E. Trably ◽  
D. Patureau ◽  
J.P. Delgenes
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Sewage Sludge ◽  
Aromatic Hydrocarbons ◽  
Agricultural Soils ◽  
Biogas Production ◽  
Bacterial Consortium ◽  
Anaerobic Treatment ◽  
Biological Degradation ◽  
Low Concentrations ◽  
Polycyclic Aromatic

Anaerobically stabilized sewage sludge has potential to partially substitute synthetic fertilizers. The main risk with the recycling of urban sludge on agricultural soils is the accumulation of unwanted products, such as trace metals and organic micropollutants. In this context, the polycyclic aromatic hydrocarbons (PAHs) are particularly monitored because of their toxic properties at low concentrations and their high resistance to biological degradation. The aim of the present study was to optimize PAHs removal during anaerobic digestion of contaminated sewage sludge. Thirteen PAHs were monitored in laboratory-scale anaerobic bioreactors under mesophilic (35°C) and thermophilic (55°C) methanogenic conditions. Abiotic losses were statistically significant for the lightest PAHs, such as fluorene, phenanthrene and anthracene. It was shown that PAH removal was due to a specific biological activity. Biological PAHs removal was significantly enhanced by an increase of the temperature from 35°C to 55°C, especially for the heaviest PAHs. Bioaugmentation experiment was also performed by addition of a PAH-adapted bacterial consortium to a non-acclimated reactor. Significant enhancement of PAHs removal was observed. It was finally shown that PAH removal efficiencies and methanogenic performances were closely linked. The rate of biogas production may be used as an indicator of bacterial activity on PAH removal.

scholarly journals Ammonium removal by a novel heterotrophic nitrifying and aerobic denitrifying bacterium Pseudomonas stutzeri KTB from wastewater

2015 ◽  
Vol 50 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Maohong Zhou ◽  
Hairen Ye ◽  
Xiaowei Zhao
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Pseudomonas Stutzeri ◽  
Culture Conditions ◽  
Aerobic Denitrification ◽  
Ammonium Concentration ◽  
Logarithmic Phase ◽  
Ammonium Removal ◽  
Removal Ratio ◽  
Initial Ph

The effects of culture conditions on a newly isolated Pseudomonas stutzeri KTB's ability to simultaneously perform heterotrophic nitrification and aerobic denitrification were investigated to determine its potential of application in nitrogen removal from wastewater. The results from experiments in the presence of 10 mmol/L of ammonium were as follows: succinate was the preferred carbon source, and the optimum C/N ratio, temperature, and initial pH were 10, 30 °C, and 7–8, respectively. Nitrogen removal took place not only in the logarithmic phase but also in the stationary phase. Under the optimum conditions, the nitrogen removal rate increased as the ammonium concentration elevated, until it was as high as 60 mmol/L. Meanwhile, the maximum specific growth rate decreased. The highest nitrogen removal rate of 0.977 mmol/L/h was observed at 60 mmol/L of ammonium and the maximum removal ratio of 85.6% at 40 mmol/L when the bacterial treatment for 48 h was completed. The strain was vulnerable to even higher ammonium loads. When incubated in anaerobically digested hennery wastewater containing 43.85 mmol/L of ammonium and 2.32 mmol/L of nitrate, the removal ratio and rate reached 82.4% and 0.397 mmol/L/h, respectively. The strain might be a great candidate for ammonium removal from wastewater.

Unconventional microbial mechanisms for the key factors influencing inorganic nitrogen removal in stormwater bioretention columns

2021 ◽  
pp. 117895
Author(s):  
Liuqin Huang ◽  
Junyue Luo ◽  
Linxin Li ◽  
Hongchen Jiang ◽  
Xiaoxi Sun ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Key Factors ◽  
Factors Influencing

scholarly journals Impact of mixing intensity on dissolved oxygen half-velocity constants in a sidestream deammonification environment

2019 ◽  
Vol 55 (2) ◽  
pp. 145-154
Author(s):  
Biao Xie ◽  
Chao Jin ◽  
Wayne J. Parker
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Bulk Phase ◽  
Batch Reactors ◽  
Ammonia Oxidizing Bacteria ◽  
Mixing Conditions ◽  
Steady State Operation ◽  
Mixing Intensity ◽  
Best Fit

Abstract A partial nitritation/anammox (PN/A) process was operated at two different mixing intensities to quantify the extent to which diffusional limitations impact process rates. At a steady-state operation, the total inorganic nitrogen removal efficiency in the bench-scale sequencing batch reactors was found to increase as mixing intensity decreased (62 and 84% for average velocity gradient (G) values of 15 and 5.3 s−1, respectively). The half-velocity constants with respect to bulk-phase dissolved oxygen (DO) concentration for ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (anammox) organisms were estimated on the basis of nitrogen removal rates that were observed in activity tests. The activity tests were conducted over a range of bulk-phase DO concentrations. The best-fit values were estimated to be 0.68 ± 0.34 and 0.54 ± 0.56 mg O2/L for G values of 15 and 5.3 s−1, respectively. The AOB values were not statistically different (p = 0.19) between mixing conditions which were consistent with AOB dominating the surface of granules. The best-fit values were estimated to be 0.13 ± 0.09 and 0.55 ± 0.40 mg O2/L for G values of 15 and 5.3 s−1, respectively, and were statistically different . The results demonstrated that mixing conditions should be considered when designing PN/A processes and provide quantitative results that can be employed to improve models of these processes. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).

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