Review of the Factors Affecting Modeling Oxygen Transfer by Fine-Pore Diffusers in Activated Sludge

2019 ◽  
Author(s):  
Gustavo Andrés Baquero-Rodríguez ◽  
Jaime Andrés Lara-Borrero ◽  
Daniel Nolasco ◽  
Diego Rosso
Keyword(s):  
Activated Sludge ◽  
Oxygen Transfer ◽  
Factors Affecting

A Critical Review of the Factors Affecting Modeling Oxygen Transfer by Fine-Pore Diffusers in Activated Sludge

2018 ◽  
Vol 90 (5) ◽  
pp. 431-441 ◽  
Author(s):  
Gustavo Andrés Baquero-Rodríguez ◽  
Jaime Andrés Lara-Borrero ◽  
Daniel Nolasco ◽  
Diego Rosso
Keyword(s):  
Activated Sludge ◽  
Critical Review ◽  
Oxygen Transfer ◽  
Factors Affecting

Study of factors affecting simultaneous nitrification and denitrification (SND)

1999 ◽  
Vol 39 (6) ◽  
pp. 61-68 ◽  
Author(s):  
Klangduen Pochana ◽  
Jürg Keller
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Physical Phenomenon ◽  
Treatment Plant ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Factors Affecting ◽  
Floc Size ◽  
Sludge Flocs ◽  
Activated Sludge Systems

Experiments have been performed to gain an understanding of the conditions and processes governing the occurrence of SND in activated sludge systems. Sequencing batch reactors (SBRs) have been operated under controlled conditions using the wastewater from the first anaerobic pond in an abattoir wastewater treatment plant. Under specific circumstances, up to 95% of total nitrogen removal through SND has been found in the system. Carbon source and oxygen concentrations were found to be important process parameters. The addition of acetate as an external carbon source resulted in a significant increase of SND activity in the system. Stepwise change of DO concentration has also been observed in this study. Experiments to determine the effect of the floc size on SND have been performed in order to test the hypothesis that SND is a physical phenomenon, governed by the diffusion of oxygen into the activated sludge flocs. Initial results support this hypothesis but further experimental confirmation is still required.

Fine Bubble Aeration Using a High Density Diffuser System

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2437-2440 ◽  
Author(s):  
K. Thatcher
Keyword(s):  
Activated Sludge ◽  
Oxygen Transfer ◽  
Oxygen Demand ◽  
High Density ◽  
Plant Performance ◽  
Energy Usage ◽  
High Quality ◽  
Transfer Rates ◽  
Fine Bubble ◽  
Activated Sludge Processes

Current developments with the activated sludge processes with highly concentrated effluents highlight the requirement to (a) reduce energy usage (b) promote the production of high quality effluent. Having observed the efforts being made to improve plant performance we became aware that current methods had to be improved. It was also noted that a period of stagnation had occurred in the development of effective aeration systems. Improved aeration methods are needed which would allow for oxygen transfer efficiencies to be greater than 2kg/kWh. Such oxygen transfer rates should be continually variable in line with the oxygen demand prevailing at any given time. In our study of activated sludge plants we found that operational and electrical/mechanical maintenance was proving to be time consuming and very costly. With these problems in mind we have designed and developed the Fine Bubble High Density Diffuser System.

Factors affecting nitrogen removal from domestic wastewater using immobilized bacteria

1998 ◽  
Vol 38 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Vasanthadevi Aravinthan ◽  
Satoshi Takizawa ◽  
Kenji Fujita ◽  
Kazuya Komatsu
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Nitrate Nitrogen ◽  
Domestic Wastewater ◽  
Nitrification Rate ◽  
Factors Affecting ◽  
Immobilized Bacteria ◽  
Bulk Oxygen ◽  
Micro Organisms ◽  
Nitrogen Loadings

The parameters affecting the nitrogen removal process by the immobilized bacteria in the anoxic-oxic process have been studied by investigating two bench scale Runs A and B. The hollow polypropylene pellets have been dosed into the anoxic reactor in Run A and into the oxic reactors of both Runs up to 24% of volume. Run B was operated with no pellets in the anoxic reactor as a control. The maximum nitrification rate of 0.4 kg NH4-N/m3d was achieved in sufficient DO (6.5 mg/l) at 15°C in the reactor with both activated sludge and immobilized micro-organisms. The volumetric nitrification rate was found to be greatly dependent on bulk oxygen concentration especially when the DO was maintained below 4 mg/l. A mathematical model developed successfully simulated the experimental results showing the variation of nitrification rate with DO. In the case of denitrification, the contribution of immobilized bacteria was prominent when lesser concentration of MLSS was present in the activated sludge in the combined immobilized and activated sludge system. The presence of immobilized bacteria in the anoxic reactor will be effective when higher nitrate nitrogen loadings are expected and the maintenance of higher MLSS than 2 g/l in an activated sludge facility is not feasible.

Determination of Some Kinetic Parameters by Respirometry

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2535-2538 ◽  
Author(s):  
M. Roš ◽  
M. Dular
Keyword(s):  
Reaction Time ◽  
Activated Sludge ◽  
Kinetic Parameters ◽  
Oxygen Transfer ◽  
Dynamic Method ◽  
Research Work ◽  
Substrate Utilisation ◽  
Relative Standard ◽  
Temperature Constant

Individual kinetic parameters such as BOD, biodegradation of wastewater, reaction time, maximal substrate rate can be determined by respirometry. For the determination of main respirometric parameters (STBOD, BODr, reaction time, etc.) overall oxygen transfer coefficient, KLa, is needed. This parameter can be determined with dynamic method in an open respirometer at limited conditions (constant temperature, constant stirring conditions). It was found out that KLa is dependent upon concentration of the activated sludge; it can be determined with about 2% of relative standard deviation. The objective of our research work was determination of maximal exogenous oxygen uptake, re max and maximal substrate utilisation, µmax, which is very important kinetic parameter at wastewater treatment. These parameters show us the maximal substrate (wastewater) utilisation for appointed activated sludge.

Practical Experience with Biological Phosphorus Removal Plants in Johannesburg

1983 ◽  
Vol 15 (3-4) ◽  
pp. 233-259 ◽  
Author(s):  
A R Pitman ◽  
S L V Venter ◽  
H A Nicholls
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Operating Experience ◽  
Practical Experience ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Factors Affecting ◽  
Process Improvements ◽  
Biological Phosphorus

This paper describes three years operating experience with two full-scale biological nutrient removal activated sludge plants. Factors affecting biological phosphorus removal are highlighted and possible process improvements suggested.

Experience with Ceramic Plate Diffusers in Large Activated Sludge Plants

1992 ◽  
Vol 25 (4-5) ◽  
pp. 127-134
Author(s):  
R. Warriner ◽  
T. C. Rooney
Keyword(s):  
Activated Sludge ◽  
Oxygen Transfer ◽  
Cost Effective ◽  
Transfer Efficiency ◽  
Ceramic Plate ◽  
Flat Plates ◽  
Higher Power ◽  
Oxygen Transfer Efficiency ◽  
Basin Floor ◽  
The Difference

Fine pore aeration systems were evaluated in a U.S.EPA sponsored study of oxygen transfer efficiency in 26 activated sludge plants. Two plants in the study, those of the Milwaukee Metropolitan Sewerage District, had aeration systems composed of flat plates grouted into containers placed flush with the basin floor. The remaining plants in the study had aeration systems utilizing various disk, dome, and tube devices that are now in far more widespread use than the flat plates. The District's aeration basins gave better oxygen transfer efficiency than the other ceramic diffuser systems studied. The difference may have been the result of the high tank area to diffuser area ratio and the low air flux rates associated with the plate systems. At one MMSD plant there were also four basins with recently installed ceramic disk diffuser systems. This provided an opportunity for side-by-side comparisons between the disks and the flat plates in containers. An analysis of diffuser system first costs and energy costs indicated that the ceramic plate system could be cost effective at higher power costs, but not at the prices presently paid by the District for power.

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