scholarly journals Effect of the Aeration Strategy on NOB Suppression in Activated Sludge and Biofilm in a Hybrid Reactor with Nitrification/Denitrification

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 72
Author(s):  
Olga Zajac ◽  
Monika Zubrowska-Sudol ◽  
Slawomir Ciesielski ◽  
Martyna Godzieba
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Oxidation Rate ◽  
No Reduction ◽  
Hybrid Reactor ◽  
Intermittent Aeration ◽  
Nitrite Oxidation ◽  
Nitrite Oxidizing Bacteria ◽  
R Value ◽  
The Impact

The purpose of the study was to analyse the impact of aeration strategies defined by the changes in the duration of aerated sub-phases, the ratio between non-aerated and aerated sub-phase times (R), and dissolved oxygen concentrations (DO) on the suppression of nitrite-oxidizing bacteria (NOB) in activated sludge and biofilm developing in a hybrid reactor with nitrification/denitrification. The primary factor causing NOB suppression both in biofilm and in activated sludge was an increase in the R-value (from 0 to 1/4 and from 1/4 to 1/3). After reducing the DO from 3 to 2 mg O2/L, there were no changes in the frequency of NOB occurrence, and no reduction in the nitrite oxidation rate was recorded. The abundance of Comammox bacteria was considerably affected by the change from continuous to intermittent aeration. Activated sludge showed a substantial increase in the quantity of clade A and B, whereas the quantity considerably decreased in biofilm.

A review of the impact and potential of intermittent aeration on continuous flow nitrifying activated sludge

2011 ◽  
Vol 32 (15) ◽  
pp. 1685-1697 ◽  
Author(s):  
Gabriela Dotro ◽  
Bruce Jefferson ◽  
Mark Jones ◽  
Peter Vale ◽  
Elise Cartmell ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
Intermittent Aeration ◽  
The Impact

Effect of Acclimation Strategy on the Biological Nitrification in the Saline Wastewater

2011 ◽  
Vol 183-185 ◽  
pp. 522-526 ◽  
Author(s):  
Ling Ling Li ◽  
Bo Yang ◽  
Peng Zhou
Keyword(s):  
Oxidation Rate ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonium Oxidation ◽  
Salt Tolerant ◽  
Nitrite Oxidation ◽  
Saline Wastewater ◽  
Nacl Concentration ◽  
Nitrite Oxidizing Bacteria ◽  
Fresh Culture

During the process of cultivation of salt-tolerant nitrifying bacteria, the increase in NaCl concentrations was carried out in two different manners. The NaCl concentration in reactor A was increased by increment of 5 g/L, while the NaCl concentration in reactor B was increased by increment of 2.5 g/L. The impacts of NaCl content on the fresh culture and two acclimated cultures were investigated, which focused upon the changes of the specific ammonium oxidation rate (SAOR) and specific nitrite oxidation rate (SNOR). The results indicated that fresh nitrifiers were severely inhibited by high salinity. At NaCl concentration of 25 g/L, ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) completely lost the nitrification capability. After 46 days of acclimation, the nitrifying bacteria could be adapted to the saline wastewater. The average SAOR and SNOR in reactor B were slightly higher than those in reactor A, which meant that low increment in salt concentration may be in favor of the development of salt-tolerant nitrifiers. But the two NaCl increasing approaches did not affect the SAOR and SNOR too much. Salt-tolerant nitrifiers could be well developed with the two acclimation manners.

Application of Three Step-Biological Pond with the Use of Aquatic Plant for Post Treatment of Petroleum Wastewater in Vietnam

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1503-1507 ◽  
Author(s):  
L. M. Triet ◽  
N. T. Viet ◽  
T. V. Thinh ◽  
H. D. Cuong ◽  
J. C. L. van Buuren
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Residence Time ◽  
Aquatic Plants ◽  
Water Hyacinth ◽  
Aquatic Plant ◽  
Post Treatment ◽  
Cod Removal ◽  
Sludge Treatment ◽  
Purification Efficiency

The effluent from activated sludge treatment of petroleum wastewater was treated with the aid of a ponding system using aquatic plants (Water Hyacinth, Chlorella, Reed). A good result was obtained in this study. Pilot pond system shows that the purification efficiency depends on the residence time of about 14 days. The petroleum removal waa 97-98 %, the COD removal was from 88-93 %. The dissolved oxygen amount (with Chlorella) increased from 0.7 mg/l to 9.8 mg/l and the pH increased from 6.9 to 8-8.6. The application of 3 step biological pond with the use of Water Hyacinth, Chlorella, Reeds for post treatment of petroleum wastewater is appropriate in Vietnam.

The Impact of a Chemostat Discharge Containing Oil Degrading Bacteria on the Biological Kinetics of a Refinery Activated Sludge Process

1988 ◽  
Vol 20 (11-12) ◽  
pp. 131-136 ◽  
Author(s):  
A. D. Wong ◽  
C. D. Goldsmith
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Waste Treatment ◽  
Treatment Plant ◽  
Utilization Rate ◽  
Activated Sludge Process ◽  
Kinetic Evaluation ◽  
Degrading Bacteria ◽  
Waste Treatment Plant ◽  
The Impact

The effect of discharging specific oil degrading bacteria from a chemostat to a refinery activated sludge process was determined biokinetically. Plant data for the kinetic evaluation of the waste treatment plant was collected before and during treatment. During treatment, the 500 gallon chemostatic growth chamber was operated on an eight hour hydraulic retention time, at a neutral pH, and was fed a mixture of refinery wastewater and simple sugars. The biokinetic constants k (days−1), Ks (mg/L), and K (L/mg-day) were determined before and after treatment by Monod and Lineweaver-Burk plots. Solids discharged and effluent organic concentrations were also evaluated against the mean cell retention time (MCRT). The maximum utilization rate, k, was found to increase from 0.47 to 0.95 days−1 during the operation of the chemostat. Subsequently, Ks increased from 141 to 556 mg/L. Effluent solids were shown to increase slightly with treatment. However, this was acceptable due to the polishing pond and the benefit of increased ability to accept shock loads of oily wastewater. The reason for the increased suspended solids in the effluent was most likely due to the continual addition of bacteria in exponential growth that were capable of responding to excess substrate. The effect of the chemostatic addition of specific microbial inocula to the refinery waste treatment plant has been to improve the overall organic removal capacity along with subsequent gains in plant stability.

Evaluation of Toxicity in Receiving Streams

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2357-2360
Author(s):  
J. Zagorc-Koncan ◽  
M. Dular
Keyword(s):  
Dissolved Oxygen ◽  
Toxic Substances ◽  
Toxicity Evaluation ◽  
Copper Cyanide ◽  
Polluted River ◽  
Design Information ◽  
Point Of Entry ◽  
Receiving Stream ◽  
The Impact

A laboratory river model for the study of self-purification inhibition in a stream containing toxic substances is presented. It enables an engineering - technological prediction of the impact of toxic substances or wastewaters on dissolved oxygen (DO) profile in an organically polluted river downstream from the point of entry of toxic effluent thus providing rapidly and inexpensively significant design information to an environmental scientist or engineer. The method was applied to the toxicity evaluation of wastewaters from electroplating industry. The effects of copper, cyanide (representing two significant constituents of this type of wastewaters) and wastewater from electroplating industry on the biodegradation of organic municipal pollution in receiving stream were evaluated experimentally.

Estimation of oxygen transfer rate in sequencing batch reactor

1996 ◽  
Vol 34 (3-4) ◽  
pp. 413-420
Author(s):  
Y. C. Liao ◽  
D. J. Lee
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Transfer Rate ◽  
Intermittent Aeration ◽  
Transient Effects ◽  
Operational Parameters ◽  
Transient Model

Transient model of oxygen transfer rate in a sequencing batch reactor is derived and solved numerically. The dissolved oxygen response under several conditions is analyzed. Effects of operational parameters and liquid bath height are studied. When with short, intermittent aeration periods, the transient effects on oxygen transfer rate may be substantial and should be taken into considerations. An example considering bioreaction is also given.

Considering the impact of intermittent discharges when modelling overflows

1998 ◽  
Vol 38 (10) ◽  
pp. 23-30
Author(s):  
Sarah Jubb ◽  
Philip Hulme ◽  
Ian Guymer ◽  
John Martin
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Preliminary Investigation ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Combined Sewer Overflows ◽  
River Hydraulics ◽  
Combined Sewer ◽  
The Impact ◽  
Curve Equation

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.

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