Substrate removal and sludge production in a batch activated-sludge process with blending

1982 ◽  
Vol 9 (3) ◽  
pp. 558-566 ◽  
Author(s):  
Ronald L. Droste ◽  
Jatinder K. Bewtra
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Oxygen Uptake Rate ◽  
Oxygen Demand ◽  
Effluent Quality ◽  
Mixed Liquor ◽  
Substrate Removal ◽  
Uptake Rates ◽  
Absorption Phenomenon ◽  
Similar Unit

Bench-scale studies were conducted on a batch-operated, activated-sludge system in which the mixed liquor was blended periodically in an Osterizer blender. A similar unit without mechanical blending was operated as a control. Synthetic organic feed of known characteristics was used as a substrate. Tests were conducted for mixed liquor volatile suspended solids (MLVSS), effluent chemical oxygen demand (COD), settleability, and oxygen uptake rate under steady-state conditions.Substrate uptake in both units was observed to be a rapid adsorption–absorption phenomenon. The nonremovable COD was significantly lower in the blended unit. Also, the oxygen uptake rates showed significant increases due to floc breakup. Settleability was good in the blended unit and the overall effluent quality had improved considerably.

Estimation of treatability of different industrial wastewaters by activated sludge oxygen uptake measurements

1999 ◽  
Vol 40 (1) ◽  
pp. 31-36 ◽  
Author(s):  
K. Orupõld ◽  
K. Hellat ◽  
T. Tenno
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Textile Industry ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Short Term ◽  
Uptake Rates ◽  
Textile Industries ◽  
Biological Treatability ◽  
Industry Wastewater

The activated sludge short-term respiration measurement is proposed for assessing the properties of activated sludge and biological treatability of wastewaters. Different influents to the wastewater treatment plant were analyzed and compared on the basis of exogenous oxygen uptake rates of activated sludge. The kinetic parameters of biodegradation processes were determined by monitoring the degradation-associated oxygen consumption in tests with different amounts of wastewaters from textile industries and tanneries. The short-term oxygen demands in the tests formed 25-45% of the biochemical oxygen demand of the textile industry wastewater.

Use of the Immediate Maximum Specific Oxygen Uptake Rate as an Activated Sludge Process Control Parameter

1992 ◽  
Vol 25 (1) ◽  
pp. 123-132 ◽  
Author(s):  
J. Y. Shamas ◽  
A. J. Englande
Keyword(s):  
Process Control ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Chemical Oxygen Demand ◽  
Uptake Rate ◽  
Control Parameter ◽  
Oxygen Uptake Rate ◽  
Control Strategies ◽  
Oxygen Demand ◽  
Specific Oxygen Uptake Rate

The immediate maximum specific oxygen uptake rate (SOURim) was investigated as a potential process control parameter for the activated sludge system. Variability in effluent quality in terms of chemical oxygen demand correlated very well with the levels of SOURim at cell residence times of 3, 5, and 10 days. Transient response studied under batch growth conditions indicated a strong correlation between the SOURim, chemical oxygen demand, and the ribonucleic acid rates of change. The SOURim can therefore be used to qualitatively and quantitatively describe a given biomass thus making it a better suited parameter for use in process control strategies.

Inhibitory effects of non-ionic surfactants on the microbial activity of activated sludge system

2009 ◽  
Vol 60 (4) ◽  
pp. 1033-1039
Author(s):  
Ma D. Coello Oviedo ◽  
D. Sales Márquez ◽  
R. Rodriguez-Barroso ◽  
J. Ma Quiroga Alonso
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Microbial Activity ◽  
Dehydrogenase Activity ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Oxygen Demand ◽  
Ionic Surfactant ◽  
Complete Control ◽  
Specific Oxygen Uptake Rate

The purpose of the present work was to study the influence of a non-ionic surfactant, a nonylphenol with four ethoxylated units (NP4EO), on the activity of the microbial population present in a laboratory-scale activated sludge unit. Traditional control methods for this type of unit were used (measurement of suspended solids and chemical oxygen demand) as well as specific techniques for the measurement of bacterial activity (dehydrogenase activity and specific oxygen uptake rate) and the results were compared. It was shown that the Specific Oxygen Uptake Rate (SOUR) is the simplest and quickest way to carry out routine control of activated sludge activity, while measuring dehydrogenase activity provides more complete control. The results obtained indicated that there was no inhibition of microbial activity at a concentration of 5 ppm of NP4EO, which was not the case with a concentration of 10 ppm.

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

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

Inhibition of sulfide generation by dosing formaldehyde and its derivatives in sewage under anaerobic conditions

2008 ◽  
Vol 57 (6) ◽  
pp. 915-919 ◽  
Author(s):  
L. Zhang ◽  
L. Mendoza ◽  
M. Marzorati ◽  
W. Verstraete
Keyword(s):  
Hydrogen Sulfide ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Oxygen Uptake Rate ◽  
Urea Formaldehyde ◽  
Nitrification Rate ◽  
Economic Aspects ◽  
Anaerobic Conditions ◽  
Activated Sludge System ◽  
The Impact

Hydrogen sulfide emission in sewers is associated with toxicity, corrosion, odor nuisance and a lot of costs. The possibility to inhibit sulfide generation by formaldehyde and its derivatives (paraformaldehyde and urea formaldehyde) has been evaluated under anaerobic conditions. The impact of formaldehyde on an activated sludge system and an appraisal of the economic aspects are also presented. The optimum dosage to inhibit sulfide generation in sewage was 12–19 mg L−1 formaldehyde. The dosages of 32 mg L−1 paraformaldehyde or 100 mg L−1 urea formaldehyde were not capable of inhibiting sulfide generation in sewage. The impact of 19 mg L−1 formaldehyde on activated sludge system was negligible in terms of COD removal, nitrification rate and oxygen uptake rate.

scholarly journals The Impact of Selected Parameters on the Condition of Activated Sludge in a Biologic Reactor in the Treatment Plant in Nowy Targ, Poland

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2657
Author(s):  
Elwira Nowobilska-Majewska ◽  
Piotr Bugajski
Keyword(s):  
Wastewater Treatment ◽  
Statistical Analysis ◽  
Activated Sludge ◽  
Partial Correlation ◽  
Oxygen Uptake Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Test Results ◽  
Partial Correlation Analysis ◽  
The Impact

The aim of this study was to determine the condition of activated sludge in the biologic reactor located in the collective wastewater treatment plant in Nowy Targ (Poland) based on OUR tests in the aspect of the impact of sludge’s concentration in the biologic reactor and dependence of BOD5/TN and BOD5/TP in wastewater flowing into the biologic reactor. The analysis was conducted based on test results from 61 samples of activated sludge taken from the biologic reactor and 61 samples of wastewater flowing into the biologic reactor. The analysis included the concentration of sludge in the biologic reactor. The following indicators were analyzed in wastewater flowing into the reactor: biochemical oxygen demand (BOD5), total nitrogen (TN) and total phosphorus (TP). The statistical analysis concerning the impact of the analyzed factors on oxygen uptake rate (OUR) tests was developed based on the Pearson’s correlation coefficient and partial correlation of many variables. Based on the results of the partial correlation analysis, nomograms were developed to determine the condition of activated sludge microorganisms (OUR) based on the BOD5/TN and BOD5/TP connection and knowledge of the sludge concentration in the bioreactor of the treatment plant. The presented nomograms can be formulated for each bioreactor based on activated sludge technology related the load of organic and biogenic pollutants in the wastewater flowing into the bioreactor and the concentration of the sludge in the bioreactor.

scholarly journals Estimating the impact of inhibitory substances on activated sludge denitrification process

2019 ◽  
Vol 14 (4) ◽  
pp. 863-871 ◽  
Author(s):  
Kati Klein ◽  
Taavo Tenno
Keyword(s):  
Standard Deviation ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Process Efficiency ◽  
Sludge Treatment ◽  
Conventional Activated Sludge ◽  
Uptake Rates ◽  
Relative Standard ◽  
The Impact ◽  
Denitrification Process

Abstract Industrial wastewater frequently contains substances which inhibit activated sludge treatment processes. Inhibitory characteristics of different substances are usually evaluated based on testing the impact of respective substance on activated sludge nitrification or oxygen uptake rates. However, denitrification is always before aerobic processes in conventional activated sludge treatment plants and thereby more exposed to inhibitory compounds. There is no easily applicable and validated method available for determination of denitrification process efficiency and inhibition. In this study, a method for evaluation of inhibition on the activated sludge denitrification process was developed and validated using 3,5-dichlorophenol (3,5-DCP) as a model inhibitory compound and additionally controlled with real wastewater produced in the shale oil industry. Average IC50 value (5.5 ± 2.2 mg L−1) for 3,5-DCP showed that denitrifiers were less sensitive than nitrifiers (IC50 = 2.9 ± 0.7 mg L−1) and more sensitive than aerobic heterotrophs (IC50 = 7.2 ± 2.4 mg L−1). Methodological aspects like accumulation of nitrite nitrogen, acclimatization of biomass and technical issues were discussed. Achieved validation characteristics were similar with ISO Standards estimating activated sludge nitrification and oxygen uptake rates, which proves the reliability of the method: standard deviation, 95.4% confidence level, relative standard deviation were calculated to be 2.2 mg L−1, 1.2 … 9.8 mg L−1 and 39.2%, respectively.

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