Use of computers for process design analysis and control: sequencing batch reactor application

1997 ◽  
Vol 35 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Asher Brenner
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Design Analysis ◽  
Computer Assisted ◽  
Operating Cycle ◽  
Operational Strategies ◽  
Conventional Activated Sludge ◽  
And Control

Computers have become a vital part of every modern wastewater treatment plant. They can be used for design, analysis, and control of the treatment process. Mathematical modelling and simulation of various process configurations, load conditions, and operational strategies lead to better understanding and improved design and operation. Computer assisted analysis of process performance and automatic control of plant units aid reduce expenses related to energy, chemicals, and man power. Stringent disposal constraints imposed in most modern countries require application of sophisticated computerized control systems to ensure high quality effluents. The sequencing batch reactor system is similar to the conventional activated sludge process in its ability to achieve biological removal of organic carbon and nutrients by a single sludge. However, due to the non-steady-state nature of the process, and to the large substrate and nutrient gradients occurring during the operating cycle, some modifications in the traditional activated sludge waste characterization and process modelling should be considered.

scholarly journals Simulation for the Performance and Economic Evaluation of Conventional Activated Sludge Process Replacing by Sequencing Batch Reactor Technology in a Petroleum Refinery Wastewater Treatment Plant

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Shahryar Jafarinejad
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Petroleum Refinery ◽  
Batch Reactor ◽  
Refinery Wastewater ◽  
Conventional Activated Sludge ◽  
Petroleum Refinery Wastewater ◽  
Project Construction

Treatment of the petroleum refinery wastewater containing complex chemicals using biological processes is usually challenging because of the inhibition and/or toxicity of these matters when they serve as microbial substrates. In addition, performance modeling and cost evaluation of processes are essential for designing, construction, and forecasting future economic requirements of the petroleum refinery wastewater treatment plants (PRWWTPs). In this study, the performance and economics of conventional activated sludge (CAS) process replacing by sequencing batch reactor (SBR) technology in a two train PRWWTP were evaluated using simulation. The final treated effluent characteristics for the PRWWTPs containing CAS + CAS and SBR + CAS processes under steady state conditions were studied and evolution of the main parameters of the final effluent during the 30 days of simulation for these plants were investigated. Finally, the total project construction, operation labor, maintenance, material, chemical, energy, and amortization costs of these plants were estimated and compared. Results demonstrated that the project construction cost of PRWWTP containing CAS + CAS processes was lower than that of PRWWTP containing SBR + CAS processes and the energy and amortization costs for both plants were higher in comparison with the operation, maintenance, material, and chemical costs. Note that this study is a computer simulation and drawing general conclusions only on the basis of computer simulation may be insufficient.

scholarly journals Design of Sequencing Batch Reactor (SBR) Treatment Plant for Abattoir Wastewater (A Case of Apa Mmini Stream)

2020 ◽  
pp. 15-21
Author(s):  
Ogbebor Daniel ◽  
Ndekwu, Benneth Onyedikachukwu
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Settling Velocity ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Design Parameters ◽  
Sequence Batch Reactor ◽  
The Impact

Aim: The study aimed at designing a wastewater treatment method for removal of (Biological Oxygen Demand) BOD5 using Sequencing batch reactor (SBR). Study Design: SBR functions as a fill-and-draw type of activated sludge system involving a single complete-mix reactor where all steps of an activated sludge process take place. Methodology: The intermittent nature of slaughterhouse wastewaters favours batch treatment methods like sequence batch reactor (SBR). Attempts to remediate the impact of this BOD5 on the stream, led to the design of a sequence batch reactor which was designed to treat slaughterhouse effluent of 1000 L. Results: The oxygen requirement for effective removal of BOD5 to 95% was determined to be 21.10513 kgO2/d, while L:B  of 3:1 was considered for the reactor. Also, air mixing pressure for the design was 0.16835 bar, while settling velocity was . Conclusion: To ensure proper treatment of BOD5 load of the slaughterhouse, a sequencing Batch reactor of 1000 litre carrying capacity was designed. For effective operation of this design, the pressure exerted by the mixing air was 0.16835 bar which was far greater than the pressure exerted by the reactor content and the nozzle. Settling velocity of 0.0003445 m/s for 0.887 hrs was required for the reactor to be stable and a theoretical air requirement of 1.6884 m³/d was calculated. Hence the power dissipated by the rising air bubbles to ensure efficient mixing of oxygen in the reactor was calculated as 26530003.91 Kilowatts. With these design parameters, the high BOD5 load downstream of the river can be treated to fall below the FMEnv recommended limit of 50 mg/l.

The bioaugmentation of sequencing batch reactor sludges for biological phosphorus removal

1997 ◽  
Vol 35 (1) ◽  
pp. 19-26 ◽  
Author(s):  
E. Belia ◽  
P. G. Smith
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Pure Culture ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Sewage Treatment Plant ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
Biological Phosphorus

The development of enhanced biological phosphorus removal (EBPR) through the bioaugmentation of a conventional activated sludge was studied. The objectives of the study were to evaluate the phosphorus removal capability of a sequencing batch reactor (SBR) when started with conventional activated sludge and augmented with a pure culture of Acinetobacter lwoffii. The effect of the addition of the pure culture on the reactor start up time, the settling properties of the sludge and on COD and nitrogen removal was also investigated. The effect of the removal of up to 70% of the bioaugmented biomass and its substitution with unconditioned sludge from a conventional sewage treatment plant was determined. This study has demonstrated that bioaugmentation can convert a conventional sewage works activated sludge to an EBPR sludge in 14 days. The sludge produced shows resilience to influent phosphate fluctuations, low D.O. and biomass replacement. The COD and nitrogen removal capabilities of the sludge and its settling properties are not affected by the addition of the pure culture.

Commissioning and operational experiences for the 160ML/d Woodman Point Sequencing Batch Reactor - control of settleability and denitrification using bioselectors

2004 ◽  
Vol 50 (7) ◽  
pp. 213-220
Author(s):  
W.K. Bagg ◽  
M.C. Newland ◽  
H. Rule
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Biological Phosphorus Removal ◽  
Storage Mechanism ◽  
Treatment Processes ◽  
Cycle Plays ◽  
Continuous Technology ◽  
Short Time

Achieving and maintaining good biomass settling characteristics is a critical process design objective for any activated sludge wastewater treatment plant (WWTP), whether intermittent or continuous technology. One way of ensuring good sludge settleability in intermittent WWTPs is the incorporation of bioselectors in the process. A bioselector is essentially a small discrete reactor volume designed primarily for carbon absorption, in which activated sludge organisms are exposed to a high substrate concentration for a relatively short time. It is normally very much smaller than an anoxic zone and the activated sludge recycle is only a fraction of that typically adopted in continuous plants. With proper conditioning, recycled biomass rapidly absorbs and stores soluble organic wastewater components before transfer to the main treatment basin. This absorption and storage mechanism, and careful management of aeration throughout the intermittent treatment cycle, plays a crucial role in many subsequent growth and treatment processes, including sludge floc formation, denitrification and biological phosphorus removal. This paper examines some design considerations, and reviews the benefits of bioselectors by reference to the commissioning and initial operation of the new 160ML/d Woodman Point Sequencing Batch Reactor in Perth, Western Australia. The applicability of bioselectors in continuous plants is discussed.

Cultivation, granulation and characteristics of anaerobic ammonium-oxidizing sludge in sequencing batch reactor

2006 ◽  
Vol 6 (6) ◽  
pp. 71-79 ◽  
Author(s):  
B.L. Hu ◽  
P. Zheng ◽  
Q. Mahmood ◽  
H.F. Qian ◽  
D.L. Wu
Keyword(s):  
Activated Sludge ◽  
Shock Loading ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Bacterial Species ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Anaerobic Sequencing Batch Reactor ◽  
Nitrite Removal

Anaerobic sequencing batch reactor (SBR) was started-up by inoculating the nitrifying activated sludge. After an operation of 72 d, the bioreactor reached at steady state with ammonia and nitrite removal percentages higher than 95%. During operation, the sludge granulated in the reactor. The morphology and internal structure of sludge granules changed conspicuously, the density increased while the color changed from khaki to red. The average granular diameter grew from 1.2 to 3.69 mm, and its settling velocity accelerated from 107.68 to 118.49 m/h. Sludge granulation improved the tolerance to hydraulic shock loading, and reduced sludge washout (TSS < 0.028 g/L). The dominant bacterial communities (filamentous and cocci) in nitrifying activated sludge were replaced by irregular shaped ANAMMOX bacterial species gradually. An increase of ANAMMOX rate was achieved with the increasing granular diameter. SBR is a useful reactor to cultivate ANAMMOX granular sludge, while granular ANAMMOX sludge thus developed can be used as seeding sludge in a pilot-scale or full scale wastewater treatment plant.

Enrichment of activated sludge in a sequencing batch reactor for polyhydroxyalkanoate production

2006 ◽  
Vol 54 (1) ◽  
pp. 119-128 ◽  
Author(s):  
M. Majone ◽  
M. Beccari ◽  
S. Di Gregorio ◽  
D. Dionisi ◽  
G. Vallini
Keyword(s):  
Steady State ◽  
Microbial Biomass ◽  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Polymer Content ◽  
Intermittent Feeding ◽  
Start Up

The paper describes the start up of a process for the production of polyhydroxyalkanoates (PHAs) from activated sludge. The excess sludge from a wastewater treatment plant was inoculated in a lab-scale sequencing batch reactor (SBR) to be enriched under aerobic conditions through intermittent feeding with a mixture of organic acids. Enriching of activated sludge was monitored through the measurement of polymer concentrations either in the mixed liquor or in the microbial biomass. The bacterial population dynamics during the SBR start up was followed through denaturing gradient gel electrophoresis and the main species present at the steady state were identified. All the measured parameters significantly changed in the SBR during first two weeks after the inoculum was seeded into the reactor, they then stabilized. At the steady state, the SBR produced 2.6 gVSS l−1 d−1, with a PHA content of 11% (on a COD basis). The enriched microbial biomass was then transferred into a batch reactor where the bacterial polymer content was increased through a new feeding. In the final batch stage, maximum storage rate and maximum polymer content in the biomass were 405 mgCOD gCOD−1 h−1 and 44% (on a COD basis), respectively. The PHA storage from the enriched microbial biomass was about 20 times faster and the PHA content was about 4 times higher than that of the inoculated activated sludge. Observations by fluorescence microscopy showed that the majority of microorganisms in the enriched biomass could be stored. Among the numerically most representative genera in the enriched biomass, Thauera, Candidatus Meganema perideroedes, and Flavobacterium were identified.

Formation and Characteristics of Aerobic Granular Sludge for Simultaneous Phosphorus and Nitrogen Removal in a SBR

2011 ◽  
Vol 356-360 ◽  
pp. 1630-1636
Author(s):  
Guo Jing Yang ◽  
Xiao Ming Li ◽  
Qi Yang ◽  
Kun Luo
Keyword(s):  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Settling Velocity ◽  
Selective Pressure ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Conventional Activated Sludge ◽  
Sedimentation Time

With inoculum sludge from a conventional activated sludge wastewater treatment plant, formation of aerobic granular sludge for simultaneous phosphorus and nitrogen removal was realized in a sequencing batch reactor by the selective pressure as a driving force. Selective pressure created by means of decreasing sedimentation time and increasing substrate loading enhanced the formation of aerobic granular sludge, which followed four consecutive stages: acclimation, granulation, growth and maturation. Under the condition that the substrate loading were increased to 500mg COD/(L•d) and 48mg NH4 +-N/(L•d), the granules were the dominant sludge forms with most of diameter about 0.5–2.0 mm, a minimal settling velocity of 0.55 cm/s and a MLSS of 6800 mg/L after 120 days operation. The granules were composed of filamentous species with varying degrees of rod- and coccal-type bacteria. Microscopic examination revealed that granules microecosystem was more stable and should be less vulnerable to the changes of mixed liquor condition.

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