Trade-off between carbon emission and effluent quality of activated sludge processes under seasonal variations of wastewater temperature and mean cell retention time

2016 ◽  
Vol 547 ◽  
pp. 331-344 ◽  
Author(s):  
Jingbo Guo ◽  
Xin Fu ◽  
G. Andrés Baquero ◽  
Reza Sobhani ◽  
Daniel A. Nolasco ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Seasonal Variations ◽  
Carbon Emission ◽  
Cell Retention ◽  
Trade Off ◽  
Effluent Quality ◽  
Activated Sludge Processes

Calibrating a side-stream membrane bioreactor using Activated Sludge Model No. 1

2005 ◽  
Vol 52 (10-11) ◽  
pp. 359-367 ◽  
Author(s):  
T. Jiang ◽  
X. Liu ◽  
M.D. Kennedy ◽  
J.C. Schippers ◽  
P.A. Vanrolleghem
Keyword(s):  
Activated Sludge ◽  
Biological Behaviour ◽  
Activated Sludge Model ◽  
Effluent Quality ◽  
Side Stream ◽  
Steady State Operation ◽  
Autotrophic Biomass ◽  
Biological Performance ◽  
Activated Sludge Processes ◽  
Influent Wastewater

Membrane bioreactors (MBRs) are attracting global interest but the mathematical modeling of the biological performance of MBRs remains very limited. This study focuses on the modeling of a side-stream MBR system using the Activated Sludge Model No. 1 (ASM1), and compares the results with the modeling of traditional activated sludge processes. ASM1 parameters relevant for the long-term biological behaviour in MBR systems were calibrated (i.e. YH = 0.72gCOD/gCOD, YA = 0.25gCOD/gN, bH = 0.25d−1, bA = 0.080d−1 and fP = 0.06), and generally agreed with the parameters in traditional activated sludge processes, with the exception that a higher autotrophic biomass decay rate was observed in the MBR. Influent wastewater characterization was proven to be a critical step in model calibration, and special care should be taken in characterizing the inert particulate COD (XI) concentration in the MBR influent. It appeared that the chemical–biological method was superior to the physical–chemical method. A sensitivity analysis for steady-state operation and DO dynamics suggested that the biological performance of the MBR system (the sludge concentration, effluent quality and the DO dynamics) are very sensitive to the parameters (i.e. YH, YA, bH, bA μmaxH and μmaxA), and influent wastewater components (XI, Ss, Xs and SNH).

A comparison of NH4/NO3 control strategies for alternating activated sludge processes

1999 ◽  
Vol 39 (4) ◽  
pp. 93-102 ◽  
Author(s):  
L. J. S. Lukasse ◽  
K. J. Keesman ◽  
A. Klapwijk ◽  
G. van Straten
Keyword(s):  
Activated Sludge ◽  
Time Delays ◽  
Control Strategies ◽  
Treatment Plant ◽  
Biological Processes ◽  
Effluent Quality ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
The Difference ◽  
Activated Sludge Processes

Four control strategies for N-removal in alternating activated sludge plants (ASP's) are compared: 1. timer-based, 2. switching the aeration on/off when depletion of nitrate/ammonium is detected, 3. switching the aeration on/off when ammonium crosses an upper/lower-bound, 4. the newly developed adaptive receding horizon optimal controller (ARHOC) as presented in Lukasse et al. (1997). The comparison is made by simulating the controllers' application to an alternating continuously-mixed activated sludge reactor preceded by a small anoxic reactor for predenitrification. The biological processes in the reactors are modelled by the activated sludge model no. 1. Realistic influent patterns, measured at a full-scale wastewater treatment plant, are used. The results show that three totally different controllers (timer-based, NH4-bounds based and ARHOC) can achieve a more or less equal effluent quality, if tuned optimally. The difference mainly occurs in the sensitivity to suboptimal tunings. The timer-based strategy has a higher aeration demand. The sensitivity of the ARHOC controller to sub-optimal tuning, known measurement time delays and changing plant loads is significantly less than that of the other controllers. Also its tuning is more natural and explicit.

Population Dynamics of Bacteria for Phosphorus Removal in Sequencing Batch Reactor (SBR) Activated Sludge Processes

1991 ◽  
Vol 23 (4-6) ◽  
pp. 755-763 ◽  
Author(s):  
M. Okada ◽  
A. Murakami ◽  
C. K. Lin ◽  
Y. Ueno ◽  
T. Okubo
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Growth Rates ◽  
Sodium Acetate ◽  
Sequencing Batch Reactor ◽  
Specific Growth ◽  
Batch Reactor ◽  
Organic Substrates ◽  
Specific Growth Rates ◽  
Activated Sludge Processes

Laboratory-scale sequencing batch reactor (SBR) activated sludge processes were operated using synthetic wastewater to clarify the effects of sludge retention time(SRT) and organic substrates on the accumulation of bio-P-bacteria. The accumulation of bio-P-bacteria could be enhanced by wide variation in concentration of organic substrates by giving a short fill period and sufficient anaerobic conditions. However, the accumulation could not be enhanced in the reactor operated with SRT less than 25 d in spite of the higher, more than 0.1 d−1, specific growth rates observed in the isolated strains of bio-P-bacteria. The specific growth rates of bio-P-bacteria were estimated at 0.040 d−1, 0.030 d−1 and 0.035 d−1 in the SBR activated sludge processes fed with sodium acetate (A), glucose and polypeptone (GP) and polypeptone (P), respectively. Therefore, a large sludge retention time would be necessary for the accumulation of bio-P-bacteria. Volatile fatty acids (VFA), such as sodium acetate (A), seemed to be more effective than other organic substrates (GP and P) for the accumulation of bio-P-bacteria in activated sludge ecosystems.

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.

Operating Experiences at Low Solids Retention Time

1984 ◽  
Vol 16 (12) ◽  
pp. 661-672 ◽  
Author(s):  
T E Wilson ◽  
W A Ambrose ◽  
H O Buhr
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Suspended Solids ◽  
Volume Index ◽  
Sludge Volume Index ◽  
Effluent Quality ◽  
Mixed Liquor ◽  
Solids Retention Time ◽  
Solids Retention ◽  
Typically Achieving

Five full scale activated sludge plants have been operated at low solids retention time (SRT, monthly averages as low as 0.8 days) and mixed liquor suspended solids (MLSS, monthly averages as low as 500 mg/l) values for 2 to 3 years. Operating results for this period are compared to 3 to 3-1/2 years of operation at conventional, higher, SRT and MLSS values. The data show that the lower SRT operation provided better effluent quality, typically achieving less than 15 mg/l of BOD5 or suspended solids, while not significantly increasing either the total (dry) sludge production or the sludge volume index (SVI). These data indicate that plants can be built and operated using significantly smaller tankage than conventionally accepted.

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