Uncertainty analysis of WWTP control strategies made feasible

2012 ◽  
Vol 47 (1) ◽  
pp. 14-29 ◽  
Author(s):  
Lorenzo Benedetti ◽  
Damien J. Batstone ◽  
Bernard De Baets ◽  
Ingmar Nopens ◽  
Peter A. Vanrolleghem
Keyword(s):  
Uncertainty Analysis ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Latin Hypercube Sampling ◽  
Uncertainty Assessment ◽  
Performance Evaluations ◽  
Uncertain Parameters ◽  
Effluent Quality ◽  
Simulation Speed ◽  
Modelling Studies

The control of wastewater treatment plants can help to achieve good effluent quality, in a complex, highly non-linear environment. A key but time-demanding component of such modelling studies is uncertainty analysis (UA). The general aims of this paper are (a) to evaluate methods for reduction of the time necessary to conduct an UA, and (b) to evaluate the sensitivity of parameters and model subsystems. Two UA studies on the Benchmark Simulation Model no. 2 (BSM2) are used to illustrate how the above mentioned aims can be achieved: (1) robustness of performance evaluations against changing operation and design conditions; and (2) uncertainty of performance evaluations for a given plant layout and operation. The main conclusions are: (1) solver settings have a large impact on simulation speed and require proper attention; (2) to reach convergence in Monte Carlo simulations with Latin Hypercube Sampling, the number of simulations should be at least 50 times the number of sampled parameters, which is more than what is reported in similar studies; and (3) the number of uncertain parameters that needs to be considered to make a proper uncertainty assessment of a model can be reduced significantly by omitting parameters that have little influence.

scholarly journals A supervisory fuzzy logic control scheme to improve effluent quality of a wastewater treatment plant

2021 ◽  
Author(s):  
S. Saravana Kumar ◽  
K. Latha
Keyword(s):  
Fuzzy Logic ◽  
Wastewater Treatment ◽  
Fuzzy Logic Controller ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Treatment Plant ◽  
Vital Role ◽  
Effluent Quality ◽  
Control Scheme ◽  
Control Schemes

Abstract The application of control strategies in wastewater treatment plants has increased to improve its performance of treating the influent. Fuzzy Logic controller plays a vital role in this work and the simulation work is being carried out in Benchmark simulation model no.1 (BSM1) framework. The attempted work proposes two control schemes with the objectives of improving the effluent quality and minimizing the number of measurements taken from the plant. The design of fuzzy control schemes is based on 5 inputs and 6 outputs in order to accomplish the objectives. Experimental results show improvement in the effluent quality and increase in the efficacy of the control system. The proposed design is implemented using MATLAB with the adaptation of 2014a.

Benchmarking of control strategies for ATAD technology: a first approach to the automatic control of sludge treatment systems

2009 ◽  
Vol 60 (2) ◽  
pp. 409-417 ◽  
Author(s):  
J. A. Zambrano ◽  
M. Gil-Martinez ◽  
M. Garcia-Sanz ◽  
I. Irizar
Keyword(s):  
Automatic Control ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Open Loop ◽  
Operating Costs ◽  
Promising Alternative ◽  
Effluent Quality ◽  
Key Factor ◽  
Simulation Protocol ◽  
Autothermal Thermophilic Aerobic Digestion

Autothermal Thermophilic Aerobic Digestion (ATAD technology) is a promising alternative to conventional digestion systems. Aeration is a key factor in the performance of these kinds of reactors, in relation to effluent quality and operating costs. At present, the realisation of automatic control in ATADs is in its infancy. Additionally, the lack of robust sensors also makes the control of these processes difficult: only redox potential and temperature sensors are reliable for operation in full-scale plants. Based as it is on the existing simulation protocols for benchmarking of control strategies for wastewater treatment plants (WWTP), this paper presents the definition and implementation of a similar protocol but specifically adapted to the needs of ATAD technology. The implemented simulation protocol has been used to validate two different control strategies for aeration (ST1 and ST2). In comparison to an open-loop operation for the ATAD, simulation results showed that the ST1 strategy was able to save aeration costs of around 2–4%. Unlike ST1, ST2 achieved maximum sludge stabilisation but at the expense of higher aeration costs.

scholarly journals Evaluation of the effluent quality parameters of wastewater treatment plant based on uncertainty analysis and post-processing approaches (case study)

2021 ◽  
Vol 83 (7) ◽  
pp. 1633-1648
Author(s):  
Nasim Hejabi ◽  
Seyed Mahdi Saghebian ◽  
Mohammad Taghi Aalami ◽  
Vahid Nourani
Keyword(s):  
Wastewater Treatment ◽  
Uncertainty Analysis ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Ensemble Methods ◽  
Quality Parameters ◽  
Support Vector ◽  
Effluent Quality ◽  
Applied Model

Abstract Wastewater treatment plants (WWTPs) are highly complicated and dynamic systems and so their appropriate operation, control, and accurate simulation are essential. The simulation of WWTPs according to the process complexity has become an important issue in growing environmental awareness. In recent decades, artificial intelligence approaches have been used as effective tools in order to investigate environmental engineering issues. In this study, the effluent quality of Tabriz WWTP was assessed using two intelligence models, namely support Vector Machine (SVM) and artificial neural network (ANN). In this regard, several models were developed based on influent variables and tested via SVM and ANN methods. Three time scales, daily, weekly, and monthly, were investigated in the modeling process. On the other hand, since applied methods were sensitive to input variables, the Monte Carlo uncertainty analysis method was used to investigate the best-applied model dependability. It was found that both models had an acceptable degree of uncertainty in modeling the effluent quality of Tabriz WWTP. Next, ensemble approaches were applied to improve the prediction performance of Tabriz WWTP. The obtained results comparison showed that the ensemble methods represented better efficiency than single approaches in predicting the performance of Tabriz WWTP.

Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1457-1466 ◽  
Author(s):  
Kazuhiro Tanaka ◽  
Minoru Tada ◽  
Mitsuo Ito ◽  
Noritugu Shimizu
Keyword(s):  
Suspended Solids ◽  
Fine Particles ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Particle Fraction ◽  
Effluent Quality ◽  
Rotating Biological Contactors ◽  
Activated Sludge Processes ◽  
Fraction Method ◽  
Final Effluent

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.

Danish Experience with Emergent Hydrophyte Treatment Systems (EHTS) and Prospects in the Light of Future Requirements on Outlet Water Quality

1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Reed Beds ◽  
Effluent Quality ◽  
Multi Stage ◽  
Run Off ◽  
Stage System

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.

Automatic buffer capacity based sensor for effluent quality monitoring

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Buffer Capacity ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Full Scale ◽  
Quality Monitoring ◽  
Effluent Quality ◽  
Capacity Curves ◽  
On Line

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.

Evaluation of Small Wastewater Treatment Plants in the County of Århus – Denmark

1993 ◽  
Vol 28 (10) ◽  
pp. 33-41
Author(s):  
Jes la Cour Jansen ◽  
Bodil Mose Pedersen ◽  
Erik Moldt
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Chemical Precipitation ◽  
Common Type ◽  
Treatment Efficiency ◽  
Effluent Quality ◽  
Different Types

Influent and effluent data from about 120 small wastewater treatment plants (100 - 2000 PE) have been collected and processed. Seven different types of plants are represented. The effluent quality and the treatment efficiency have been evaluated. The most common type of plant is mechanical/biological treatment plants. Some of them are nitrifying and some are also extended for chemical precipitation of phosphorus. Constructed wetlands and biological sandfilters are also represented among the small wastewater treatment plants.

scholarly journals Global Evaluation of Wastewater Treatment Plants Control Strategies Including CO 2 Emissions

2017 ◽  
Vol 50 (1) ◽  
pp. 12956-12961 ◽  
Author(s):  
Marian Barbu ◽  
Ramon Vilanova ◽  
Montse Meneses ◽  
Ignacio Santin
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Global Evaluation

scholarly journals Energetic flexibility on wastewater treatment plants

2017 ◽  
Vol 76 (5) ◽  
pp. 1225-1233 ◽  
Author(s):  
M. Schäfer ◽  
I. Hobus ◽  
T. G. Schmitt
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Energy Systems ◽  
Energy Market ◽  
Control Parameters ◽  
Effluent Quality ◽  
The Future ◽  
Energy Consuming ◽  
Characteristic Values ◽  
And Control

In the future, an additional potential of control reserve as well as storage capacities will be required to compensate fluctuating renewable energy availability. The operation of energy systems will change and flexibility in energy generation and consumption will rise to a valuable asset. Wastewater treatment plants (WWTPs) are capable of providing the flexibility needed, not only with their energy generators but also in terms of their energy consuming aggregates on the plant. To meet challenges of the future in regard to energy purchase and to participate in and contribute to such a volatile energy market, WWTPs have to reveal their energetic potential as a flexible service provider. Based on the evaluated literature and a detailed analysis of aggregates on a pilot WWTP an aggregate management has been developed to shift loads and provide a procedure to identify usable aggregates, characteristic values and control parameters to ensure effluent quality. The results show that WWTPs have a significant potential to provide energetic flexibility. Even for vulnerable components such as aeration systems, load-shifting is possible with appropriate control parameters and reasonable time slots without endangering system functionality.

Performance evaluation of different wastewater treatment technologies operating in a developing country

2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Septic Tank ◽  
Operational Parameters ◽  
Technical Literature ◽  
Effluent Quality ◽  
Loading Rates ◽  
Treatment Processes ◽  
Treatment Technologies ◽  
Uasb Reactors

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found. The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.

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