RESEARCH PAPERS : ESTIMATION OF ACTIVE NITROSOMONAS AND NITROBACTER CONCENTRATIONS IN ACTIVATED SLUDGE USING NITROGENOUS OXYGEN UPTAKE RATE

2004 ◽  
Vol 9 (3) ◽  
pp. 130-142 ◽  
Author(s):  
Sun-Jip Kim
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Research Papers

Mass transfer impacts in flocculent and granular biomass from SBR systems

2004 ◽  
Vol 50 (10) ◽  
pp. 203-212 ◽  
Author(s):  
D. Gapes ◽  
B.-M. Wilén ◽  
J. Keller
Keyword(s):  
Mass Transfer ◽  
Particle Size ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Gas Analysis ◽  
Average Particle

An experimental study was conducted to describe mass transfer impacts within nitrifying aggregates sourced from sequencing batch reactor (SBR) activated sludge systems. Flocculent and granular sludge with high nitrification activity was obtained in two laboratory SBR systems, supplied with a synthetic, ammonium-based feed. The flocculent biomass was fractionated using a sieving procedure, in order to obtain biomass fractions with different particle size distributions. The oxygen uptake rate (OUR) response to changes in dissolved oxygen concentration was measured under highly controlled conditions in a titrimetric and off-gas analysis (TOGA) sensor, and the results used to assess mass transfer effects. As the average particle size of the biomass increased, mass transfer limitations were found to increase significantly. Empirically fitted, apparent KS,O2 values were demonstrated to be highly dependent on particle size, and reflect the mass transfer limitations occurring in the aggregates within a given system. Such parameters thus have little to do with the actual biokinetic parameter from which they are derived. The results obtained from the TOGA sensor study were consistent with those obtained from a microelectrode study on the same nitrifying granules. Together, these studies add considerable weight to the conclusion that consideration of external and internal mass transfer limitations is vital to the accurate description of activated sludge treatment processes, particularly those with a high oxygen uptake rate.

Disturbance observer for estimation of oxygen uptake rate in an activated sludge reactor

2016 ◽  
Author(s):  
Francisco Jadilson dos Santos Silva ◽  
Euler C. T. de Macedo ◽  
Sebastian Y. C. Catunda ◽  
Carlos E. T. Dorea ◽  
Adrianus C. Van Haandel
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Disturbance Observer ◽  
Oxygen Uptake Rate ◽  
Activated Sludge Reactor

Measuring the activities of higher organisms in activated sludge by means of mechanical shearing pretreatment and oxygen uptake rate

2010 ◽  
Vol 44 (13) ◽  
pp. 3993-4001 ◽  
Author(s):  
Xiaodi Hao ◽  
Qilin Wang ◽  
Yali Cao ◽  
Mark C.M. van Loosdrecht
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Mechanical Shearing

scholarly journals Specific Oxygen Uptake Rate and Mass Transfer Coefficient in Activated Sludge System

2019 ◽  
Vol 4 (2) ◽  
pp. 24-32
Author(s):  
S.H. Tan ◽  
◽  
Jamaiatul Lailah M.J. ◽  
Aida Isma M.I. ◽  
◽  
...  
Keyword(s):  
Mass Transfer ◽  
Oxygen Uptake ◽  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Uptake Rate ◽  
Oxygen Transfer ◽  
Oxygen Uptake Rate ◽  
Specific Oxygen Uptake Rate

Activated sludge process is one of the effective methods in biological wastewater treatment and the impact of oxygen transfer through aeration process has the most important breakthroughs as it served as the largest consumer in the treatment. Aeration is an energy demanding process. Oxygen transfer into an activated sludge is a very challenging issue in the field of multiphase flows. Apart from the physical mass transfer phenomena between gas, liquid and solids phases, the transport mechanisms are also overlapped by time and temperature, varying microbial activity, impurity loads, adsorption and desorption processes. Oxygen uptake rate (OUR) for microbial population in the activated sludge system is important parameter to determine the amount of oxygen consumed during aerobic heterotropic biodegradation in the system. Evaluation of specific oxygen uptake rate (SOUR) and the volumetric mass transfer coefficient (KLA) of oxygen for three different wastewater treatment processes, namely conventional activated sludge (CAS), oxidation ditch (OD) and sequencing batch reactor (SBR) treating municipal wastewater in Kuala Lumpur have been carried out. In-situ and ex-situ measurement of pH, dissolved oxygen (DO), temperature, MLSS and MLVSS were carried out. In the activated sludge treatment, very low concentration of dissolved oxygen may cause the wastewater to turn septic resulting in death of bacteria or in active due to unstable anaerobic conditions. Conversely, an excessive dissolved oxygen may result to high energy and high 25 operating cost. Higher flowrate may also cause dissolved oxygen to rise, reducing the quality of sludge and slowing the denitrification process in the system. Results revealed that the OUR for SBR, OD and CAS were 9.582 mg O2 /L/hr, 10.074 mg O2 /L/hr and 13.764 mg O2 /L/hr, respectively. Low oxygen uptake rate indicates a low rate of microbial respiration. By computing the OUR, the mass transfer coefficient could be evaluated. It should be noted that among the treatment system in this study, the conventional activated sludge shows the highest mass transfer coefficient and specific oxygen uptake rate of 2.038 hr-1 and 15.605 mg O2 /g MLVSS/hr, respectively. Improving the oxygen transfer rate and reducing aeration in the system could achieve a cost-effective aeration system.

Oxygen uptake rate as control parameter for carbon management in high-rate activated sludge

2018 ◽  
Vol 2018 (5) ◽  
pp. 304-307
Author(s):  
Tim Van Winckel ◽  
Ola Olagunju ◽  
Belinda Sturm ◽  
Siegfried E Vlaeminck ◽  
Kimberly L Jones ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Control Parameter ◽  
Oxygen Uptake Rate ◽  
High Rate ◽  
Carbon Management

scholarly journals Method for Estimating the Toxicity of Chemicals to Activated Sludge. III. Effects of Commercial Detergents on Oxygen Uptake Rate.

Eisei kagaku ◽  
1992 ◽  
Vol 38 (6) ◽  
pp. 523-528 ◽  
Author(s):  
YUICHI MIHARA ◽  
KATSUE HAGIOITA ◽  
NAOMI FURUSAWA ◽  
TSUYOSHI KONDO ◽  
TOMOKO OGASAWARA ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Commercial Detergents

Design of aeration systems in activated sludge plants at different wastewater temperatures

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
T. Guenkel ◽  
M. Wagner
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Uptake Rate ◽  
Oxygen Transfer Rate ◽  
Decisive Factor ◽  
Volume Increase ◽  
The Impact

The standard oxygen transfer rate (SOTR) is the decisive factor in the dimensioning of activated sludge plants. It depends on the required oxygen uptake rate (OUR) by microorganisms. The dependencies of the SOTR and OUR on the wastewater temperature (range 5–30 °C) are discussed. It is shown that the absolute values of the SOTR depend only slightly on the wastewater temperature, while the specific values, in relation to the aerated tank volume, increase considerably as a function of the wastewater temperature. Within this context, the decisive dimensioning temperature is discussed. In addition, two design approaches for determining the SOTR, temperature-dependant and temperature-independent, are presented and compared, showing the impact of the water dependency. Finally, the sensitivity of the decisive factors for determining the SOTR is discussed, particularly addressing the influence of the α-value.

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