Monitoring pH and ORP in a SHARON reactor

2011 ◽  
Vol 63 (11) ◽  
pp. 2505-2512 ◽  
Author(s):  
J. Claros ◽  
J. Serralta ◽  
A. Seco ◽  
J. Ferrer ◽  
D. Aguado
Keyword(s):  
Real Time ◽  
Reduction Potential ◽  
Ammonia Removal ◽  
Real Time Control ◽  
Time Control ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
High Ammonia ◽  
On Line ◽  
One Year

This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH and ORP can be used to develop a real-time control system aimed at optimizing the length of both aerobic and anoxic stages. Real-time control of methanol addition can be carried out by using the information provided by these probes: excessive methanol addition in the anoxic stage is clearly detected in the ORP profile of the following aerobic phase, while a deficit of methanol is detected in both pH and ORP profiles of that anoxic phase. Moreover, other valuable information such as the amount of ammonia nitrified, failures in DO measurements, excessive stirring during the anoxic stage and methanol dosage in the aerobic phase was also provided by the pH and ORP profiles.

Real-Time Control of Wastewater Treatment Systems Using ORP

1993 ◽  
Vol 28 (11-12) ◽  
pp. 273-282 ◽  
Author(s):  
David G. Wareham ◽  
Kenneth J. Hall ◽  
Donald S. Mavinic
Keyword(s):  
Real Time ◽  
Reduction Potential ◽  
Sewage Treatment ◽  
Real Time Control ◽  
Automated Control ◽  
Time Curve ◽  
Time Control ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Wastewater Treatment Systems

Oxidation-Reduction Potential (ORP) can be used as a process control parameter for real-time automated control of batch sewage treatment systems. Results suggest that ORP has great potential for the control of anoxic sequences, since the distinct breakpoint in the ORP-time curve correlates to the disappearance of nitrates.

REAL-TIME CONTROL OF NITROGEN REMOVAL AT FULL-SCALE USING OXIDATION REDUCTION POTENTIAL

1994 ◽  
Vol 30 (4) ◽  
pp. 207-210 ◽  
Author(s):  
K. Wouters-Wasiak ◽  
A. Héduit ◽  
J. M. Audic ◽  
F. Lefèvre
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Reduction Potential ◽  
Treatment Plant ◽  
Full Scale ◽  
Real Time Control ◽  
Time Control ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Aeration Conditions

Full-scale studies at a 16,000 p.e. wastewater treatment plant were carried out to examine the use of oxidation-reduction potential (ORP) (and dissolved oxygen (DO) concentrations for real-time monitoring of biological nutrient control. Breakpoints in DO and ORP time profiles proved particularly useful (with correct aeration conditions) in optimising nitrogen removal.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

Modifications of rainfall runoff and decision finding models for on-line simulation in real time control

1999 ◽  
Vol 39 (9) ◽  
pp. 201-207
Author(s):  
Andreas Cassar ◽  
Hans-Reinhard Verworn
Keyword(s):  
Real Time ◽  
Urban Drainage ◽  
Rain Event ◽  
Rainfall Runoff ◽  
Real Time Control ◽  
Design Storm ◽  
Time Control ◽  
Timing Data ◽  
On Line ◽  
Rainfall Runoff Model

Most of the existing rainfall runoff models for urban drainage systems have been designed for off-line calculations. With a design storm or a historical rain event and the model system the rainfall runoff processes are simulated, the faster the better. Since very recently, hydrodynamic models have been considered to be much too slow for real time applications. However, with the computing power of today - and even more so of tomorrow - very complex and detailed models may be run on-line and in real time. While the algorithms basically remain the same as for off-line simulations, problems concerning timing, data management and inter process communication have to be identified and solved. This paper describes the upgrading of the existing hydrodynamic rainfall runoff model HYSTEM/EXTRAN and the decision finding model INTL for real time performance, their implementation on a network of UNIX stations and the experiences from running them within an urban drainage real time control project. The main focus is not on what the models do but how they are put into action and made to run smoothly embedded in all the processes necessary in operational real time control.

Toward a Real Time Control of Toolpath in Milling Processes

2013 ◽  
Vol 554-557 ◽  
pp. 706-713 ◽  
Author(s):  
Fabien Poulhaon ◽  
Matthieu Rauch ◽  
Adrien Leygue ◽  
Jean Yves Hascoet ◽  
Francisco Chinesta
Keyword(s):  
Real Time ◽  
Constant Thickness ◽  
Efficient Production ◽  
Cnc Machine ◽  
Real Time Control ◽  
Time Control ◽  
Online Measurements ◽  
Bilateral Approach ◽  
On Line ◽  
Cnc Controller

Real-time control of manufacturing processes is a challenging issue for nowadays industry. The need for ever more efficient production requires new strategies in order to make correct decisions in an acceptable time. In a large number of cases, operators working on a CNC machine tool have a reduced number of possibilities for interacting in real-time with the machine. Numerical simulation based control is in that sense an appealing alternative to the conventional approach since it provides the operator with an additional source of information, confirming his choices or in reverse suggesting a more adapted strategy. The main goal of this work is to propose a method to move from a bilateral approach (operator and CNC controller) to a trilateral one where the simulation is an active component of the manufacturing process. This paper focuses on a simple issue sometimes encountered in milling processes: how to remove a constant thickness of material at the surface of a part whose exact geometry is unknown? The difficulty lies in the choice of an appropriate trajectory for the tool. So far the method which is employed consists in acquiring the geometry of the part thanks to a palpation step made prior to milling. However, this step has to be repeated for each part and can become rather fastidious as the size of the part increases. The approach presented here gets rid of the palpation step and makes use of online measurements for identifying the real geometry and correcting the trajectory of the tool in accordance. By monitoring the forces applying on the tool (directly on the NC), we have access to the milling depth and therefore to the geometry of the part at several locations along the trajectory of the tool. This information is used as an input data for our numerical model running on an external device, which finally derives an approximation for the geometry. An optimized trajectory is then obtained and is updated on the machine. This procedure is repeated as the tool moves forward and it allows for a fast and robust on-line correction of the toolpath.

Effect of co-substrate, biomass and sulfate concentration on the performance of a control strategy used to determine the anaerobic stage length of an anaerobic/aerobic SBR degrading p-nitrophenol

2005 ◽  
Vol 52 (1-2) ◽  
pp. 441-447 ◽  
Author(s):  
G. Buitrón ◽  
G. Moreno ◽  
M.E. García ◽  
J. Moreno
Keyword(s):  
Significant Influence ◽  
Control Strategy ◽  
Reduction Potential ◽  
Biomass Concentration ◽  
Sulfate Concentration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Acid Ratio ◽  
Line Measurement ◽  
On Line

The effect of the p-nitrophenol to propionic acid ratio, the biomass concentration, and the presence of sulfates on the performance of a control strategy of an anaerobic/aerobic SBR degrading p-nitrophenol was studied. The duration of the anaerobic stage was controlled by an algorithm based on the on-line measurement of the oxidation-reduction potential, which indicates the end of the reduction of p-nitrophenol to p-aminophenol. It was observed that no significant influence on the performance of the algorithm was found when the co-substrate, the biomass concentration and the presence of sulfates were varied, indicating the robustness of the control strategy. Only for the case when a low concentration of co-substrate was used, was there no transformation of p-nitrophenol.

scholarly journals Real-Time Control of the Heating of an Airfoil

2012 ◽  
Author(s):  
Francoise Rétat-Masson ◽  
Francisco Chinesta ◽  
Adrien Leygue ◽  
Elias Cueto ◽  
Laurent Dala ◽  
...  
Keyword(s):  
Real Time ◽  
Additional Data ◽  
Proper Generalized Decomposition ◽  
Real Time Control ◽  
Simulation Tools ◽  
Time Control ◽  
Application Systems ◽  
Simulation Based ◽  
On Line ◽  
Measurement Devices

Dynamic Data-Driven Application Systems constitute nowadays one of the most challenging applications of simulation-based Engineering Science [1]. DDDAS imply a set of techniques that allow the linkage of simulation tools with measurement devices for real-time control of systems and processes [2]. DDDAS entails the ability to dynamically incorporate additional data into an executing application, and in reverse, the ability of an application to dynamically steer the measurement process. These systems need accurate and fast simulation tools, hence the off-line computations to limit as much as possible the on-line computations. In order to obtain the most efficient solver, all the sources of variability are introduced as extra-coordinates as to solve only once the model off-line to obtain its most general solution to be then considered in on-line purpose. However, such models result defined in highly multidimensional spaces. A technique recently proposed, called Proper Generalized Decomposition [3], allows circumventing this redoubtable curse of dimensionality.

An application of real-time control systems to robotics

Robotica ◽  
2001 ◽  
Vol 19 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Carmen Monroy ◽  
Ricardo Campa ◽  
Rafael Kelly
Keyword(s):  
Control Systems ◽  
Real Time ◽  
Control Algorithm ◽  
Computing Environment ◽  
Real Time Control ◽  
Time Control ◽  
On Line ◽  
Robot Performance ◽  
Single Processor ◽  
Selection Of

This paper illustrates basic concepts of real-time control systems through the application of a real-time single-processor computing environment for the control of a robotic arm. The paper describes elements for the selection of the real-time architecture, the control algorithm and the graphical user interface. The system provides an opportunity for users to verify the robot performance by changing on-line the controller parameters and the shape of the desired motion.

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