Impact of reactive settler models on simulated WWTP performance

2006 ◽  
Vol 53 (1) ◽  
pp. 159-167 ◽  
Author(s):  
K.V. Gernaey ◽  
U. Jeppsson ◽  
D.J. Batstone ◽  
P. Ingildsen
Keyword(s):  
Steady State ◽  
Treatment Plant ◽  
Simulation Studies ◽  
Plant Model ◽  
Model Simulations ◽  
N Removal ◽  
Whole Plant ◽  
Model Block ◽  
Simulation Results

Including a reactive settler model in a wastewater treatment plant model allows representation of the biological reactions taking place in the sludge blanket in the settler, something that is neglected in many simulation studies. The idea of including a reactive settler model is investigated for an ASM1 case study. Simulations with a whole plant model including the non-reactive Takács settler model are used as a reference, and are compared to simulation results considering two reactive settler models. The first is a return sludge model block removing oxygen and a user-defined fraction of nitrate, combined with a non-reactive Takács settler. The second is a fully reactive ASM1 Takács settler model. Simulations with the ASM1 reactive settler model predicted a 15.3% and 7.4% improvement of the simulated N removal performance, for constant (steady-state) and dynamic influent conditions respectively. The oxygen/nitrate return sludge model block predicts a 10% improvement of N removal performance under dynamic conditions, and might be the better modelling option for ASM1 plants: it is computationally more efficient and it will not overrate the importance of decay processes in the settler.

scholarly journals Virtual phyllotaxis and real plant model cases

2008 ◽  
Vol 35 (10) ◽  
pp. 1025 ◽  
Author(s):  
Beata Zagórska-Marek ◽  
Marcin Szpak
Keyword(s):  
Apical Meristem ◽  
Geometric Model ◽  
Ontogenetic Changes ◽  
Plant Model ◽  
Phyllotactic Pattern ◽  
Random Manner ◽  
Simulation Results ◽  
Unknown Signal ◽  
Real Plant

Phyllotactic pattern results from genetic control of lateral primordia size (physiological or physical) relative to the size of organogenic lateral surface of shoot apical meristem (SAM). In order to understand the diversity of patterns and ontogenetic transitions of phyllotaxis we have developed a geometric model allowing changes of the above proportion in a computer simulation of SAM’s growth. The results of serial simulations confirmed that many phyllotactic patterns (including most esoteric ones) and ontogenetic transitions known from real plant model cases can be easily obtained in silico. Properties of virtual patterns often deviated from those of ideal mathematical lattices but closely resembled those of the natural ones. This proved the assumptions of the model, such as initiation in the first available space or ontogenetic changes in primordia size, to be quite realistic. Confrontation of simulation results with some sequences of real phyllotactic patterns (case study Verbena) questions the autonomy of SAM in its organogenic activity and suggests the involvement of unknown signal positioning primordia in a non-random manner in the first available space.

scholarly journals Biological treatment of landfill leachate: efford landfill, Hampshire, UK - a case study

2019 ◽  
pp. 377-387
Author(s):  
Steve Last ◽  
Jonty Olufsen ◽  
Howard Robinson
Keyword(s):  
United Kingdom ◽  
Biological Treatment ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Treatment Technique ◽  
Leachate Treatment ◽  
Best Available Techniques ◽  
The United Kingdom ◽  
N Removal

Demand for of on-site treatment schemes that are capable of treating landfill leachates to highstandards has grown substantially during the last two decades. Increasingly, plants are beingrequired to discharge high quality effluents directly into surface watercourses, or to provide ahigh degree of treatment prior to discharge into the public sewerage system. This trend is certainto continue - primarily driven in the United Kingdom in recent months by the requirements of theEU IPPC Directive, which demands the application of Best Available Techniques (BAT), and bythe EU Water Framework Directive.Aerobic biological treatment of leachate from domestic landfills has widely been shown to be themost appropriate, reliable and successful treatment technique to consistently meet stringentdischarge constraints with minimal operator input. The cost of this technology is also oftenfavourable, when compared with alternative processes. More than 50 plants of this type arecurrently operational in the United Kingdom, making it by far the most widely adopted on-sitetreatment technology, and many other examples exist overseas.This paper provides a detailed case study of the design, construction and commissioning of abiological, Sequencing Batch Reactor (SBR) leachate treatment plant for Hampshire CountyCouncil, at Efford Landfill Site in the New Forest in Hampshire, UK.Since plant commissioning was completed by the authors during early 2003, extensive anddetailed monitoring data have been collected. These are presented for the plant, which is capable 3 of treating up to 150 m /day of strong methanogenic leachate (ammoniacal-N from 600-1 000mg/1), and are compared with treatment performances achieved at other full-scale leachatetreatment plants. The paper shows 80D5 and ammoniacal-N removal efficiencies in excess of99%.Results also show the efficiency of polishing treatment in a reed bed, before discharge of finaleffluent to public sewer.

scholarly journals Development of a risk assessment based technique for design/retrofitting of WWTPs

2001 ◽  
Vol 43 (7) ◽  
pp. 287-294 ◽  
Author(s):  
D. Rousseau ◽  
F. Verdonck ◽  
O. Moerman ◽  
R. Carrette ◽  
C. Thoeye ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Model Parameters ◽  
Probabilistic Modelling ◽  
Hypothetical Case ◽  
Deterministic Models ◽  
Plant Model ◽  
Modelling Techniques

Up to now, within the design/retrofit of wastewater treatment plants (WWTPs), deterministic models were used to evaluate different scenarios on their merits in terms of effluent compliance. This paper describes an approach in which a Monte Carlo engine is coupled to a deterministic treatment plant model, followed by risk interpretation in the form of concentration - duration - frequency (cdf) curves of norm exceedance. The combination of probabilistic modelling techniques with the currently available deterministic models allows to determine the probability of exceeding the effluent limits of a WWTP. This percentage of exceedance is accompanied by confidence intervals resulting from the inherent uncertainty of influent characteristics and model parameters. The approach is illustrated for a hypothetical case study, consisting of a denitrifying plant model inspired by the benchmark model described by Spanjers et al.

Simulation of a transient failure in a wastewater treatment plant: a case study

1997 ◽  
Vol 36 (5) ◽  
pp. 349-355 ◽  
Author(s):  
Stéphane Rouleau ◽  
Paul Lessard ◽  
Didier Bellefleur
Keyword(s):  
Model Calibration ◽  
Field Data ◽  
Treatment Plant ◽  
Plant Model ◽  
Evaluation Exercise ◽  
Wet Weather ◽  
Rain Events ◽  
Intensive Sampling ◽  
Transient Failure

Very few case studies of treatment plant model calibration with field data have been reported in the literature, and none with data collected during rain events and showing sludge blanket overflows. The objective of this paper is thus to present the results of an evaluation exercise done with data collected through intensive sampling during rain events. The results show that it is possible to simulate the behaviour of a plant during a wet weather period with the usual models found in the literature.

DESIGN-BUILD: AN EFFECTIVE APPROACH FOR ARCHITECTURE STUDIO EDUCATION

2018 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
Nabil Mohareb ◽  
Sara Maassarani
Keyword(s):  
Material Selection ◽  
Environmental Constraints ◽  
Design Project ◽  
Construction Methods ◽  
Physical Scale ◽  
Design Build ◽  
Simulation Results ◽  
Education Process ◽  
Real Target

Current architecture studios are missing an important phase in the education process, which is constructing the students’ conceptual ideas on a real physical scale. The design-build approach enables the students to test their ideas, theories, material selection, construction methods, environmental constraints, simulation results, level of space functionality and other important aspects when used by real target clients in an existing context. This paper aims to highlight the importance of using the design-build method through discussing a design project case study carried out by the Masters of Architecture design programme students at Beirut Arab University, who have built prototype units for refugees on a 1:1 scale.

Side effects of cultured bacteria addition in wastewater collection system on plant operations – a case study

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Yanjin Liu ◽  
Giraldo Eugenio
Keyword(s):  
Energy Use ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Collection System ◽  
Oil And Grease ◽  
Odor Control ◽  
Plant Operations ◽  
Cultured Bacteria ◽  
Wastewater Collection

Cultured bacteria addition is one of the technologies used for odor control and FOG (fat, oil, and grease) removal in wastewater collection systems. This study investigated the efficiency of bacterial addition on wastewater odor control by conducting a set of full scale trials in a 60,000 cubic meter per day system for a period of two years. The objectives of this study were: (i) to identify factors that could impact wastewater treatment plant (WWTP) operations due to the effect of bacterial addition in the collection system, (ii) to estimate/understand the level of those impacts, and (iii) to present some interesting findings from the completed case study. The plant operation data before and during the bacterial addition were reviewed. The application of the cultured bacteria presented in the study was found to have significant impacts on the operation of the WWTP in terms of influent biological oxygen demand (BOD) and total suspended solids (TSS) loading, primary settling, sludge production, energy use, dissolved sulfides concentration, and methane production.

Dynamic simulation of sludge blanket movements in a full-scale rectangular sedimentation basin

1996 ◽  
Vol 33 (1) ◽  
pp. 89-99 ◽  
Author(s):  
F. Göhle ◽  
A. Finnson ◽  
B. Hultman
Keyword(s):  
Dynamic Simulation ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Simulation Studies ◽  
Separation Processes ◽  
Sedimentation Basin ◽  
Near Future ◽  
Sludge Concentration

Bromma sewage treatment plant in Stockholm is the second largest plant in Stockholm and will in the near future have requirements for nitrogen removal. This means that a higher sludge age must be used in the aeration basin. This may be accomplished by an increase of the sludge concentration up to values until the limiting solids flux is exceeded. Measurement of the sludge blanket level is a possibility for better control of the sedimentation basin. Different measurements were performed to evaluate the main factors influencing the level. Dynamic simulation studies were performed at Bromma sewage treatment plant in Stockholm of the sludge blanket level and the return sludge concentration in a full-scale sedimentation basin. The simulations were performed with the help of a Danish simulation package, EFOR (1992), in which both reactions in the aeration basin (mainly based on the IAWPRC model) and separation processes in the sedimentation basin (both clarification and thickening) can be studied. The thickening model is based on the solids flux theory and the Vesilind formula (1979). Different methods were compared for determination and use of characteristic parameters in the Vesilind formula.

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