Model-based evaluation of an on-line control strategy for SBRs based on OUR and ORP measurements

2006 ◽  
Vol 53 (4-5) ◽  
pp. 161-169 ◽  
Author(s):  
Ll. Corominas ◽  
G. Sin ◽  
S. Puig ◽  
A. Traore ◽  
M. Balaguer ◽  
...  

Application of control strategies for existing wastewater treatment technologies becomes necessary to meet ever-stricter effluent legislations and reduce the associated treatment costs. In the case of SBR technology, controlling the phase scheduling is one of the key aspects of SBR operation. In this study a calibrated mechanistic model based on the ASM1 was used to evaluate an on-line control strategy for the SBR phase-scheduling and compare it with the SBR's performance using no control strategy. To evaluate the performance, reference indices relating to the effluent quality, the required energy for aeration and the treated wastewater volume were used. The results showed that it is possible to maintain optimal SBR performance in the studied system at minimal costs by on-line control of the length of the aerobic and anoxic phases.

2001 ◽  
Vol 44 (2-3) ◽  
pp. 145-154 ◽  
Author(s):  
D. Demey ◽  
B. Vanderhaegen ◽  
H. Vanhooren ◽  
J. Liessens ◽  
L. Van Eyck ◽  
...  

In this paper, the practical implementation and validation of advanced control strategies, designed using model based techniques, at an industrial wastewater treatment plant is demonstrated. The plant under study is treating the wastewater of a large pharmaceutical production facility. The process characteristics of the wastewater treatment were quantified by means of tracer tests, intensive measurement campaigns and the use of on-line sensors. In parallel, a dynamical model of the complete wastewater plant was developed according to the specific kinetic characteristics of the sludge and the highly varying composition of the industrial wastewater. Based on real-time data and dynamic models, control strategies for the equalisation system, the polymer dosing and phosphorus addition were established. The control strategies are being integrated in the existing SCADA system combining traditional PLC technology with robust PC based control calculations. The use of intelligent control in wastewater treatment offers a wide spectrum of possibilities to upgrade existing plants, to increase the capacity of the plant and to eliminate peaks. This can result in a more stable and secure overall performance and, finally, in cost savings. The use of on-line sensors has a potential not only for monitoring concentrations, but also for manipulating flows and concentrations. This way the performance of the plant can be secured.


1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete

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.


1999 ◽  
Vol 39 (4) ◽  
pp. 103-111 ◽  
Author(s):  
Frank Obenaus ◽  
Karl-Heinz Rosenwinkel ◽  
Jens Alex ◽  
Ralf Tschepetzki ◽  
Ulrich Jumar

This report presents the main components of a system for the model-based control of aerobic biological wastewater treatment plants. The crucial component is a model which is linked to the actual processes via several interfaces and which contains a unit which can immediately follow up the current process state. The simulation calculation of the model is based on data which are yielded by on-line measuring devices. If the sensors should fail at times, there are available a number of alternative concepts, some of which are based on the calculations of artificial neural networks or linear methods.


2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling

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.


2006 ◽  
Vol 53 (11) ◽  
pp. 1-9 ◽  
Author(s):  
A.J. Englande ◽  
W.W. Eckenfelder ◽  
G. Jin

The focus of this paper is on variability concerns in wastewater treatment and approaches to control unacceptable fluctuations in effluent quality. Areas considered include: factors contributing to variability in both waste loads and process technology performance; variability assessment; control of variability employing the process best management practice (BMP); design/operation of biological waste treatment technologies for variability reduction; and modelling to enhance process control.


2008 ◽  
Vol 57 (7) ◽  
pp. 1037-1045 ◽  
Author(s):  
G. Mannina ◽  
G. Mancini ◽  
M. Torregrossa ◽  
G. Viviani

A semi-empirical mechanistic model able to simulate the dynamics of a stabilization reservoir was developed incorporating both settling of particulate components and chemical/biological processes. Several factors affecting the reservoir effluent quality were taken into account: hydraulics and hydrology, solar radiation, atmospheric reaeration, algae, zooplankton, organic matter, pathogen bacteria, and sediment-water interaction. The model quantifies the specific influence of each factor on effluent quality, evaluating the correlation between the different considered factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacteria. The model was transferred into a computational code in order to provide a useful and versatile tool for water resource planning management issues. The model was verified by comparing simulated results with full-scale data collected from a small reservoir (Sicily, IT) filled with partially treated wastewater. The reservoir has a volume of 11,000 m3, a maximum depth of 6.3 m and a mean depth of about 5 m. The monitoring period lasted four months during which the reservoir operated in different hydraulics conditions: as a standard batch reactor and as a continuous flow reactor. The model was able to reproduce the behaviour of the principal simulated parameters thus representing a potential tool for the management and performance optimization of these peculiar storage/treatment systems.


1998 ◽  
Vol 120 (1) ◽  
pp. 57-67 ◽  
Author(s):  
A. M. Shawky ◽  
M. A. Elbestawi

In this paper a real-time model-based geometric control system is proposed for workpiece accuracy in bar turning. An on-line ultrasonic measurement system that operates in the presence of cutting fluid is employed for workpiece diameter measurement. A state space mechanistic model is used to overcome the delay in the feedback loop. A Kalman Filter is used in a predictor-corrector fashion to update model predictions using on-line measurements. A full state feedback controller with an integral control action is designed and used to manipulate the tool position in real-time for machining error compensation. The performance of the proposed control strategy is evaluated through cutting experiments performed on a CNC turret lathe retrofitted with an open architecture controller.


Author(s):  
Ahmad Reda ◽  
József Vásárhelyi

AbstractDespite the advanced technologies used in recent years, the lack of robust systems still exists. The automated steering system is a critical and complex task in the domain of the autonomous vehicle’s applications. This paper is a part of project that deals with model-based control strategy as one of the most common control strategies. The main objective is to present the implementations of Model Predictive Control (MPC) for an autonomous vehicle steering system in regards to trajectory tracking application. The obtained results are analysed and the efficiency of the use of MPC controller were discussed based on its behaviour and performance.


1998 ◽  
Vol 38 (3) ◽  
pp. 291-297 ◽  
Author(s):  
N. Puznava ◽  
S. Zeghal ◽  
E. Reddet

The objective of this work is to propose a simple but efficient way of controlling the carbon addition for the post-denitrification process in order to comply with regulatory constraints and optimize operating cost. A Biostyr® pilot column filled with polystyrene beads was used for the experiments. In order to simulate a secondary treated water from a nitrifying stage with a carbon source addition, the feed water was composed of river water dosed with nitrates, phosphates and methanol. Methanol was added initially with no control (at different constant rates) and in a second stage with different control strategies based on the on-line measurement of inlet and/or outlet nitrate concentrations. This simple dosing mode proved to be very efficient in set-point tracking to ensure the effluent quality and in minimizing the methanol addition (up to 20% less methanol consumption), thus optimizing operation costs.


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