scholarly journals Assessment of toxicity and kinetic effects of erythromycin on activated sludge consortium by fast respirometry method

2021 ◽  
Vol 8 (3) ◽  
pp. 205-214
Author(s):  
Hajar Aghili Dehnavi ◽  
Mohammad Mahdi Amin ◽  
Ali Fatehizadeh ◽  
Hossein Movahedian Attar ◽  
Karim Ebrahimpour ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Oxygen Uptake Rate ◽  
Nitrification Inhibitor ◽  
Oxygen Demand ◽  
Metabolic Functions ◽  
Kinetic Coefficients ◽  
Half Maximal Effective Concentration ◽  
Kinetic Effects

Background: The present study aimed to assess the acute impact of erythromycin (ERY) as an inhibitor on peptone mixture utilization of activated sludge (AS) consortium. Methods: For this purpose, the inhibition of oxygen consumption was used based on the ISO 8192:2007 procedure. In this method, the AS consortium (10-day age) was extracted from lab-scale membrane bioreactor, then, percentage inhibition for total, heterotrophic, and nitrifying microorganisms, in separate batch respirometric tests were calculated in the absence and presence of N-allylthiourea (ATU) as a specific Nitrification inhibitor. Results: The obtained data showed that the height of oxygen uptake rate (OUR) profiles and amount of oxygen consumption reduced with increasing ERY dose. The half-maximal effective concentration (EC50) of ERY for heterotrophic and nitrifier microorganisms were 269.4 and 1243.1 mg/L, respectively. In Run 1, the kinetic coefficients bH, fA,H, YH, and µH were calculated as 2.61 d-1, 0.44, 0.4945 mg VSS/mg COD, and 0.047 d-1, respectively. Also, for maximum ERY concentration (1000 mg/L), the kinetic coefficients bH., fA,H, YH, and µH were calculated as 2.27 d-1, 0.3, 0.4983 mg VSS/mg COD, and 0.0049 d-1, respectively. Conclusion: The findings showed that the inhibitory impact of ERY was observed as a decrease in the amount of oxygen consumption by OUR profiles in rapid respirometric method (ISO 8192), which offered a novel insight for the acute inhibitory impact of this antibiotic. Also, chemical oxygen demand (COD) as an overall substrate parameter is most helpful in interpreting the behavior and the metabolic functions of AS systems.

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.

Sludge production and oxygen demand in nutrient removal activated sludge systems

1996 ◽  
Vol 34 (5-6) ◽  
pp. 43-50 ◽  
Author(s):  
P. S. Barker ◽  
P. L. Dold
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Suspended Solids ◽  
Model Simulation ◽  
Oxygen Demand ◽  
Biological Nutrient Removal ◽  
Solids Concentration ◽  
Volatile Solids ◽  
Activated Sludge Systems

Results of model simulations indicate that without the assumption of COD loss, predictions of oxygen consumption and volatile suspended solids production are significantly over-estimated for biological excess phosphorus removal (BEPR) activated sludge systems (and to a lesser extent anoxic-aerobic systems). These systems apparently consume less oxygen and produce less volatile solids than aerobic systems for the same amount of COD removal. A general model for biological nutrient removal systems has recently been presented by Barker and Dold. Three mechanisms for COD loss are suggested, based on results of COD balances for different types of activated sludge system. Model simulation results with and without the assumption of COD loss are discussed, as well as the influence of influent COD composition on predictions of volatile suspended solids concentration/production and oxygen consumption.

Comparative study of membrane bioreactor (MBR) and activated sludge processes in the treatment of Moroccan domestic wastewater

2018 ◽  
Vol 78 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
S. Kitanou ◽  
M. Tahri ◽  
B. Bachiri ◽  
M. Mahi ◽  
M. Hafsi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Effluent Quality ◽  
Conventional Activated Sludge ◽  
Activated Sludge Processes

Abstract The study was based on an external pilot-scale membrane bioreactor (MBR) with a ceramic membrane compared to a conventional activated sludge process (ASP) plant. Both systems received their influent from domestic wastewater. The MBR produced an effluent of much better quality than the ASP in terms of total suspended solids (TSS), 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). Other effluent quality parameters also indicated substantial differences between the ASP and the MBR. This study leads to the conclusion that in the case of domestic wastewater, MBR treatment leads to excellent effluent quality. Hence, the replacement of ASP by MBR may be justified on the basis of the improved removal of solids, nutrients, and micropollutants. Furthermore, in terms of reuse the high quality of the treated water allows it to be reused for irrigation.

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.

Comparison of the removal of phthalates and other organic pollutants from industrial wastewaters in membrane bioreactor and conventional activated sludge treatment plants

2009 ◽  
Vol 60 (9) ◽  
pp. 2425-2437 ◽  
Author(s):  
A. Llop ◽  
F. Borrull ◽  
E. Pocurull
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Wastewater Treatment Plants ◽  
Organic Pollutant ◽  
Oxygen Demand ◽  
Quality Parameters ◽  
Sludge Treatment ◽  
Operational Conditions ◽  
Industrial Wastewaters ◽  
Conventional Activated Sludge

In recent years greater attention has been paid to the presence of pollutants in wastewater treatment plants, mainly because of strict environmental regulations and the possibility of reusing treated water in industrial processes. Since some organic pollutant compounds are not sufficiently removed in conventional activated sludge treatment (CAST) plants, new treatment processes have been developed, such as membrane bioreactors (MBRs). In this study a submerged membrane bioreactor (MBR) was used to treat mixed industrial wastewaters in parallel with a CAST plant. Two hydraulic retention times (HRT) of wastewater were tested as one of the operational conditions of MBR and the quality of effluents of the two processes were studied and compared. Several general quality parameters were analysed in wastewaters: chemical oxygen demand (COD), pH, conductivity, nitrogen, phosphate, suspended solids (SS) and turbidity. The two systems reduced COD by around 90%. SS was reduced by around 81% in the CAST plant and around 90% in the MBR plant. The results for the other general parameters were similar or better in the MBR process, which worked at a lower HRT. We also studied the removal of a group of six phthalates and bis(2-ethylhexyl)adipate ester by SPME/GC—MS in the two treatment plants. Most of these compounds were not completely removed in the two treatment plants and were identified at low μg l−1 levels. We also tentatively identify some organic compounds in the wastewaters. Most of the compounds we found in the influent, MBR effluent and CAST effluent were benzene derivates, styrene, naphthalene and naphthalene derivates, and phenol derivates.

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.

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

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