Evaluation of the impacts of model-based operation of SBRs on activated sludge microbial community

2006 ◽  
Vol 54 (1) ◽  
pp. 157-166 ◽  
Author(s):  
G. Sin ◽  
R. Govoreanu ◽  
N. Boon ◽  
G. Schelstraete ◽  
P.A. Vanrolleghem
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Pilot Scale ◽  
Optimal Operation ◽  
Community Level ◽  
Molecular Monitoring ◽  
Process Dynamics ◽  
Model Based ◽  
Nutrient Removal Efficiency ◽  
The Stability

Impact of model-based operation of nutrient removing SBRs on the stability of activated sludge population was studied in this contribution. The optimal operation scenario found by the systematic model-based optimisation protocol of Sin et al. (Wat. Sci. Tech., 2004, 50(10), 97–105) was applied to a pilot-scale SBR and observed to considerably improve the nutrient removal efficiency in the system. Further, the process dynamics was observed to change under the optimal operation scenario, e.g. the nitrite route prevailed and also filamentous bulking was provoked in the SBR system. At the microbial community level as monitored by DGGE, a transient shift was observed to gradually take place parallel to the shift into the optimal operation scenario. This implies that the model-based optimisation of a nutrient removing SBR causes changes at the microbial community level. This opens future perspectives to incorporate the valuable information from the molecular monitoring of activated sludge into the model-based optimisation methodologies. In this way, it is expected that model-based optimisation approaches will better cover complex and dynamic aspects of activated sludge systems.

Batch test procedures as tools for calibration of the activated sludge model - a pilot scale demonstration

1998 ◽  
Vol 37 (4-5) ◽  
pp. 235-242 ◽  
Author(s):  
Gert Holm Kristensen ◽  
Jes la Cour Jansen ◽  
Per Elberg Jørgensen
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Model Calibration ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Test Procedures ◽  
Process Dynamics ◽  
Analysis System ◽  
Nitrate And Nitrite ◽  
The Impact

Various mathematical models have been developed to facilitate the design and operation of biological nutrient removal plants. Proper calibration of such models can be a difficult task due to the large number of variable process coefficients. The paper describes a strategy for model calibration based on batch characterizations of wastewater and activated sludge biomass and demonstrates its applicability through modelling of the process dynamics in a highly dynamic activated sludge pilot plant. A comprehensive experimental programme was undertaken comprising batch characterizations of readily degradable and easily hydrolysable COD in influent wastewater, maximum and endogenous process rates for functional microorganism groups in the activated sludge, and half-saturation process constants to describe the impact of oxygen on nitrification and denitrification. An on-line measurement of ammonia and nitrate and nitrite using a Flow Injection Analysis System was conducted for two consecutive days to study the process dynamics in a BioDenitro pilot plant for two parallel activated sludge process tanks. It was possible to closely mimic the dynamics of the nitrogen removal processes in the two tanks based on the model calibration strategy using wastewater and biomass characteristics determined in batch experiments.

Application of a model-based optimisation methodology for nutrient removing SBRs leads to falsification of the model

2006 ◽  
Vol 53 (4-5) ◽  
pp. 95-103 ◽  
Author(s):  
G. Sin ◽  
K. Villez ◽  
P.A. Vanrolleghem
Keyword(s):  
Expert Knowledge ◽  
Pilot Scale ◽  
Optimal Operation ◽  
Mechanistic Models ◽  
Model Based ◽  
Improve Model ◽  
Better Than ◽  
Activated Sludge Systems ◽  
P Removal

Recently, a model-based optimisation methodology for SBR operation has been developed and an optimal operation scenario proposed to improve N and P removal in a pilot-scale SBR. In this study, this optimal operation scenario was implemented and evaluated. The results of the implementation showed that the SBR performance was improved by approximately 50 and 40% for total nitrogen and phosphorous removal, respectively, which was better than predicted by the model. However, the long-term SBR performance was found to be unstable, particularly owing to settling problems developed after the implementation. When confronted with reality, the model used for the optimisation of the operation was found to be invalid. The model was unable to predict the nitrite build-up provoked by the optimal operation scenario. These results imply that changing the operation of an SBR system using a model may significantly change the behaviour of the system beyond the (unknown) application domain of the model. This is simply because the mechanistic models currently do not cover all the aspects of activated sludge systems, e.g. settling and adaptation of the microbial community. To further improve model-application practices, expert knowledge (not contained in the models) can be valuable and should be incorporated into model-based process optimisations.

Effect of Diatomite Additive on Biomass Respiratory Activity in Activated Sludge

2011 ◽  
Vol 347-353 ◽  
pp. 264-268
Author(s):  
Wen Qi Zhang ◽  
Pin Hua Rao
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Coal Gasification ◽  
Respiratory Activity ◽  
Pilot Scale ◽  
Activated Sludge Process ◽  
Total Phenols ◽  
Biomass Activity ◽  
Coal Gasification Wastewater ◽  
The Stability

Laboratory and pilot scale experiments indicated that the diatomite additive could improve the stability of activated sludge process and the efficiency of COD removal for coal gasification wastewater treatment. In this paper, the effect of diatomite additive on biomass respiratory activity was studied to investigate the enhancing mechanism. Experimental results showed that diatomite additive could enhance biomass activity obviously when the biomass activity was inhibited by the wastewater with total phenols concentration of 188.9 mg/L -501.2 mg/L. It could be concluded that the mechanism of diatomite enhancing biomass activity were its adsorption of phenols and concentration of DO.

Biomass dewaterability, filterability and settleability in a membrane bioreactor operated with different sludge ages

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
P. Pavan ◽  
C. Cavinato ◽  
D. Bolzonella ◽  
F. Fatone ◽  
F. Cecchi
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Loading Rate ◽  
Pilot Scale ◽  
Critical Conditions ◽  
Organic Loading Rate ◽  
Two Phase ◽  
Anaerobic Digesters ◽  
Working Volume ◽  
The Stability

The results of 2 years experiments on thermophilic single and two-phase anaerobic co-digestion process on activated sludge and agro-wastes are presented. Solid agro-waste (mainly fruit and vegetable residuals from markets) and waste activated sludge were used as substrates. A pilot scale CSTR of 200 l working volume was used for single phase test, while an 0.8 m3 digester was added to study two-phase experiments. Treating only wasted sludge, the initial organic loading rate (OLR) was 0.7kgTVS/m3 d; then it was increased up to 2, 4 and 6 kgTVS/m3 d by OFMSW addition. Following OFMSW increase in the feed, it was found out the increase of GPR from 0.12 to 3.12 m3/m3 d and SGP from 0.16 to 0.51 m3/kgTVS in single phase. The stability of the process was showed also in the most critical operative conditions. Two phase experiments didn't show important differences to the single phase test in the range of OLRs studied up to now (up to 4 kgTVS/m3 d), clearly showing that these are not critical conditions for the process, that can be carried out in single phase in all the range studied. Considering the option of retrofitting the anaerobic digesters of the existing sludge line in WWTPs, the obtained data give important indications about process feasibility.

Modelling of activated sludge for textile wastewaters

1998 ◽  
Vol 38 (4-5) ◽  
pp. 9-17 ◽  
Author(s):  
F. Germirli Babuna ◽  
D. Orhon ◽  
E. Ubay Çokgör ◽  
G. Insel ◽  
B. Yaprakli
Keyword(s):  
Activated Sludge ◽  
Comprehensive Evaluation ◽  
Component Model ◽  
Activated Sludge Process ◽  
Experimental Basis ◽  
Model Simulations ◽  
Effluent Quality ◽  
Model Based ◽  
Major Process ◽  
Textile Wastewaters

A comprehensive evaluation of four different textile wastewaters was carried out to set the experimental basis for the modelling of activated sludge process. Experiments involved beside conventional characterization, detailed COD fractionation and assessment of major kinetic and stoichiometric coefficients by means of respirometric measurements. A multi-component model based on the endogenous decay concept was used for the kinetic interpretation and design of activated sludge. The fate and variation of major process components affecting effluent quality with the sludge age were evaluated by means of model simulations.

scholarly journals The diversity of active microbial groups in an activated sludge process treating painting process wastewater

2020 ◽  
Vol 148 ◽  
pp. 01002
Author(s):  
Herto Dwi Ariesyady ◽  
Mentari Rizki Mayanda ◽  
Tsukasa Ito
Keyword(s):  
Wastewater Treatment ◽  
Microbial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Rrna Gene ◽  
Activated Sludge Process ◽  
Painting Process ◽  
Process Wastewater

Activated sludge process is one of the wastewater treatment method that is applied for many wastewater types including painting process wastewater of automotive industry. This wastewater is well-known to have high heavy metals concentration which could deteriorate water environment if appropriate performance of the wastewater treatment could not be achieved. In this study, we monitored microbial community diversity in a Painting Biological Treatment (PBT) system. We applied a combination of cultivation and genotypic biological methods based on 16S rRNA gene sequence analysis to identify the diversity of active microbial community. The results showed that active microbes that could grow in this activated sludge system were dominated by Gram-negative bacteria. Based on 16S rRNA gene sequencing analysis, it was revealed that their microbial diversity has close association with Bacterium strain E286, Isosphaera pallida, Lycinibacillus fusiformis, Microbacterium sp., Orchobactrum sp., Pseudomonas guariconensis, Pseudomonas sp. strain MR84, Pseudomonas sp. MC 54, Serpens sp., Stenotrophomonas acidaminiphila, and Xylella fastidiosa with similarity of 86 – 99%. This findings reflects that microbial community in a Painting Biological Treatment (PBT) system using activated sludge process could adapt with xenobiotics in the wastewater and has a wide range of diversity indicating a complex metabolism mechanism in the treatment process.

scholarly journals Do initial concentration and activated sludge seasonality affect pharmaceutical biotransformation rate constants?

2021 ◽  
Author(s):  
Tamara J. H. M. van Bergen ◽  
Ana B. Rios-Miguel ◽  
Tom M. Nolte ◽  
Ad M. J. Ragas ◽  
Rosalie van Zelm ◽  
...  
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Community Composition ◽  
Rate Constants ◽  
Wastewater Treatment Plants ◽  
Microbial Community Composition ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Initial Concentration ◽  
Different Seasons

Abstract Pharmaceuticals find their way to the aquatic environment via wastewater treatment plants (WWTPs). Biotransformation plays an important role in mitigating environmental risks; however, a mechanistic understanding of involved processes is limited. The aim of this study was to evaluate potential relationships between first-order biotransformation rate constants (kb) of nine pharmaceuticals and initial concentration of the selected compounds, and sampling season of the used activated sludge inocula. Four-day bottle experiments were performed with activated sludge from WWTP Groesbeek (The Netherlands) of two different seasons, summer and winter, spiked with two environmentally relevant concentrations (3 and 30 nM) of pharmaceuticals. Concentrations of the compounds were measured by LC–MS/MS, microbial community composition was assessed by 16S rRNA gene amplicon sequencing, and kb values were calculated. The biodegradable pharmaceuticals were acetaminophen, metformin, metoprolol, terbutaline, and phenazone (ranked from high to low biotransformation rates). Carbamazepine, diatrizoic acid, diclofenac, and fluoxetine were not converted. Summer and winter inocula did not show significant differences in microbial community composition, but resulted in a slightly different kb for some pharmaceuticals. Likely microbial activity was responsible instead of community composition. In the same inoculum, different kb values were measured, depending on initial concentration. In general, biodegradable compounds had a higher kb when the initial concentration was higher. This demonstrates that Michealis-Menten kinetic theory has shortcomings for some pharmaceuticals at low, environmentally relevant concentrations and that the pharmaceutical concentration should be taken into account when measuring the kb in order to reliably predict the fate of pharmaceuticals in the WWTP. Key points • Biotransformation and sorption of pharmaceuticals were assessed in activated sludge. • Higher initial concentrations resulted in higher biotransformation rate constants for biodegradable pharmaceuticals. • Summer and winter inocula produced slightly different biotransformation rate constants although microbial community composition did not significantly change. Graphical abstract

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

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