On-line monitoring equipment for wastewater treatment processes: state of the art

2003 ◽  
Vol 47 (2) ◽  
pp. 1-34 ◽  
Author(s):  
P.A. Vanrolleghem ◽  
D.S. Lee
Keyword(s):  
Wastewater Treatment ◽  
Control Systems ◽  
Model Calibration ◽  
Wastewater Treatment Plants ◽  
Monitoring And Control ◽  
Monitoring Equipment ◽  
Automatic Control Systems ◽  
Treatment Processes ◽  
On Line ◽  
And Control

A (non-exhaustive) survey of new and existing technologies for the monitoring of wastewater treatment plants is presented. Emphasis is given to the way these sensors can provide insight in the ongoing (bio-) processes. Three different uses for sensors can be found: for monitoring (operator support), in automatic control systems and as tools for plant auditing/optimization/modelling by consultants. From this, sensors have been classified in two basic types: (i) reliable, simple and low maintenance sensors for day-to-day monitoring and control and (ii) advanced, higher maintenance sensors that are used in auditing, model calibration and optimisation. The paper is organized according to the typical unit processes of biological wastewater treatment systems: anaerobic digestion, activated sludge, nutrient removal and sedimentation. Attention is drawn to a number of practical problems associated with the use of sophisticated sensors in the harsh (dirty) conditions of wastewater treatment processes. The use of autocalibration and built-in sensor checks, cleaning systems and reliable sample preparation units is illustrated. The paper ends with a discussion of the applicability of the different sensors.

Advanced monitoring and control of anaerobic wastewater treatment plants: fault detection and isolation

2001 ◽  
Vol 43 (7) ◽  
pp. 183-190 ◽  
Author(s):  
J-Ph Steyer ◽  
A. Genovesi ◽  
J. Harmand
Keyword(s):  
Wastewater Treatment ◽  
Fault Detection ◽  
Wastewater Treatment Plants ◽  
Real Life ◽  
Practical Interest ◽  
Fault Detection And Isolation ◽  
Monitoring And Control ◽  
On Line ◽  
And Control ◽  
Large Improvement

In this paper, a fault detection and isolation approach using fuzzy logic is described for on-line analysis of problems occurring in anaerobic digestion processes. The measurements available on the process are preprocessed to build a vector of fault residuals indicating the magnitude of the problems. This vector is classified into a prespecified category (i.e., a class) which is a state of the system, according to discrimination fuzzy rules. Three different types of classes were defined in a hierarchical structure : sensors faults, sub-process faults and process faults. This approach was developed to handle in real time both technical and biological problems. Demonstration of the practical interest of this study was made using real life experiments and large improvement of the reliability and safety of the process was obtained, thus optimizing the overall wastewater treatment.

scholarly journals Opportunities for microbial electrochemistry in municipal wastewater treatment – an overview

2014 ◽  
Vol 69 (7) ◽  
pp. 1359-1372 ◽  
Author(s):  
Oskar Modin ◽  
David J. I. Gustavsson
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Energy Content ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes ◽  
Municipal Wastewater Treatment Plants ◽  
And Control ◽  
The Impact

Microbial bioelectrochemical systems (BESs) utilize living microorganisms to drive oxidation and reduction reactions at solid electrodes. BESs could potentially be used at municipal wastewater treatment plants (WWTPs) to recover the energy content of organic matter, to produce chemicals useful at the site, or to monitor and control biological treatment processes. In this paper, we review bioelectrochemical technologies that could be applied for municipal wastewater treatment. Sjölunda WWTP in Malmö, Sweden, is used as an example to illustrate how the different technologies potentially could be integrated into an existing treatment plant and the impact they could have on the plant's utilization of energy and chemicals.

On-line automated monitoring and control systems for CO2 and O2 in aerobic and anaerobic solid-state fermentations

1994 ◽  
Vol 29 (1) ◽  
pp. 13-24 ◽  
Author(s):  
G. Saucedo-Castañeda ◽  
M.R. Trejo-Hernández ◽  
B.K. Lonsane ◽  
J.M. Navarro ◽  
S. Roussos ◽  
...  
Keyword(s):  
Solid State ◽  
Control Systems ◽  
Monitoring And Control ◽  
Automated Monitoring ◽  
On Line ◽  
Monitoring And Control Systems ◽  
And Control ◽  
Aerobic And Anaerobic

Spectroscopic Ellipsometry as a Tool for On-Line Monitoring and Control of Surface Treatment Processes

2006 ◽  
Vol 518 ◽  
pp. 423-430 ◽  
Author(s):  
Christian Eitzinger ◽  
Jan Fikar ◽  
C. Forsich ◽  
J. Humlíček ◽  
Albrecht Krüger ◽  
...  
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Monitoring And Control ◽  
Monitoring Tool ◽  
Material Technology ◽  
Modern Material ◽  
Loop Control ◽  
Whole Process ◽  
Treatment Processes ◽  
On Line ◽  
And Control

Modern material technology relies increasingly on processes for surface modification and coating. Generally, we are lacking a possibility to monitor the progress of such processes. Thus the outcome can only be analyzed after the end of the whole process cycle. We are proposing to use spectroscopic ellipsometry (SE) as an on-line monitoring tool. SE, as an optical method, is not affected by high temperatures, process gases, plasmas, etc. It can be used as a monitoring tool or a sensor for closed loop control of processes. The main difficulty is the on-line interpretation of SE data. Depending on the nature of the process monitored or controlled, different models are used for the interpretation. These models predict the SE response depending on different parameters describing the surface under investigation. A fitting process is used to solve the inverse problem, i.e. extracting material data from the SE spectra. We expect increased process stability and shorter development time as a practical benefit from the use of SE.

Advanced monitoring and control of anaerobic wastewater treatment plants: diagnosis and supervision by a fuzzy-based expert system

2001 ◽  
Vol 43 (7) ◽  
pp. 191-198 ◽  
Author(s):  
A. Puñal ◽  
J. Rodríguez ◽  
A. Franco ◽  
E. F. Carrasco ◽  
E. Roca ◽  
...  
Keyword(s):  
Expert System ◽  
Expert Knowledge ◽  
Wastewater Treatment Plants ◽  
Rule Base ◽  
Monitoring And Control ◽  
Anaerobic Digesters ◽  
On Line ◽  
And Control ◽  
Logic Inference ◽  
Microsoft Windows

A fuzzy-based expert system (ES) for the diagnosis and supervision for anaerobic digesters is presented. The system was developed in a Microsoft Windows support using fuzzy logic inference together with a rule base for the implementation of expert knowledge. The ES runs on-line through three main modules, which determine the state and trend of the process, and the best set points for the actuation on the final control elements of the plant. Two further modules run in parallel, when they are required by the operator, using off-line and on-line information for the detection of inhibition due to toxic compounds in the process and for the validation of the on-line diagnosis. The diagnosis and supervision ES was tuned up in order to adjust the membership functions describing the process, and lately tested, running on-line, to study the response of the rule base.

scholarly journals Infrared Thermometry for Early Detection of Drought Stress in Chrysanthemum

HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Margaretha Blom-Zandstra ◽  
Klaas Metselaar
Keyword(s):  
Soil Moisture ◽  
Control Systems ◽  
Soil Water ◽  
Water Status ◽  
Water Shortage ◽  
Leaf Temperature ◽  
Monitoring And Control ◽  
Climate Chamber ◽  
On Line ◽  
And Control

Strict legislation on the release of water and nutrients into the subsoil exists in the Netherlands. Therefore, on-line monitoring and control systems are being developed to tune the supply of water and nutrients to the plants' demand for optimal control of production and reduction of system losses. In this context sensors and control systems are important tools. For Chrysanthemum, however, the effect of reduced irrigation on crop production is not well understood and more data from adequate sensors are required to establish critical soil moisture levels for an optimal crop water status and growth. We studied the effect of different soil water levels and soil desiccation in a climate chamber and under changing light intensities in a greenhouse to assess the critical soil moisture status for optimal growth of Chrysanthemum plants. Moreover, we studied the efficacy of infrared (IR) thermometry as a useful tool for on-line monitoring and control under the conditions of Dutch greenhouse horticulture. It is shown in this study that under moderate climate conditions plants start to suffer from water shortage when soil moisture potential pF reaches values below –32 kPa. Water status of the plant can very well be monitored on-line in a greenhouse as changes in leaf temperature due to water shortage can be detected by IR thermometry, especially at summer radiation levels. In the climate chamber however, leaf temperature did not respond to changes in soil water status, suggesting that the environmental settings of the climate chamber are unsuitable for these kind of experiments. In two of the three experiments at different levels of global radiation a change in leaf temperature is explained by a change in water regime. We conclude that regression analysis of high frequency on-line IR monitoring may be a useful tool for expost analyses of irrigation regimes at high light intensities, and may lead to interesting insights in crop responses.

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