Lessons learnt from the application of a multi-variable controller for nitrogen removal in the Mekolalde wastewater treatment plant: good simulation practices in control

2014 ◽  
Vol 69 (6) ◽  
pp. 1289-1297 ◽  
Author(s):  
I. Irizar ◽  
S. Beltrán ◽  
G. Urchegui ◽  
G. Izko ◽  
O. Fernández ◽  
...  

Although often perceived as tools for use by scientists, mathematical modelling and simulation become indispensable when control engineers have to design controllers for real-life wastewater treatment plants (WWTPs). Nonetheless, the design of effective controllers in the wastewater domain using simulations requires effects, such as the nonlinearity of actuators, the time response of sensors, plant model uncertainties, etc. to have been reproduced beforehand. Otherwise, control solutions verified by simulation can completely underperform under real conditions. This study demonstrates that, when all the above effects are included at the outset, a systematic use of simulations guarantees high quality controllers in a relatively short period of time. The above is exemplified through the Mekolalde WWTP, where a comprehensive simulation study was conducted in order to develop a control product for nitrogen removal. Since its activation in May 2011, the designed controller has been permanently working in the plant which, from this time onwards, has experienced significant improvements in the quality of water discharges combined with a lower utilization of electricity for wastewater treatment.

2013 ◽  
Vol 67 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
R. Barat ◽  
J. Serralta ◽  
M. V. Ruano ◽  
E. Jiménez ◽  
J. Ribes ◽  
...  

This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions.


1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.


2019 ◽  
Vol 252 ◽  
pp. 09009
Author(s):  
Dariusz Majerek ◽  
Sylwia Duda ◽  
Roman Babko ◽  
Marcin K. Widomski

The assessment of the ratio of self-purification processes in the natural environment, including the water bodies of streams and rivers is possible by the means of the numerical modelling. Nonetheless, the reliability of results of the qualitative numerical calculations may be affected by the quality of the collected input data and efficiency of the model calibration. The commonly required input data include pollutants characteristics and coefficients for empirical equations of their transport and decay, while calibration of a model requires series of measurements of selected pollutants concentration in water. This paper presents studies of concentration of pollutants measured in the treated sanitary wastewater discharged to the Bystrzyca river from municipal wastewater treatment plant, and their concentrations measured directly in the river, above and below the location of discharge point. The performed qualitative measurements of treated sewage discharged from municipal wastewater treatment plant and water of the Bystrzyca river included determination of COD, BOD5, N-NH4, N-NO2, N-NNO3, TKN, TN, TP and TSS concentration. The presented results of measurements are the first step in development and calibration of the model, allowing to successfully predict the influence of discharged sanitary wastewater on quality of water in the river.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.


2013 ◽  
Vol 39 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Katarzyna Pawęska ◽  
Krzysztof Kuczewski

Abstract The paper presents results of research concerning operating of five small wastewater treatment plants working in two different technologies: hydrobotanical wastewater treatment plant and constructed wetland. Each object was designed for the treatment of domestic sewage after preliminary mechanical treatment in a septic tank. Hydrobotanical wastewater treatment plants and one of constructed wetland beds were built for treating sewage produced in educational institutions and resort. In the article attention is paid to possibility of exceeding the maximum allowable concentration of pollutants for three main indicators of pollution: BOD5, COD, and total suspension. The reduction of these indices is required by the Regulation of the Minister of Environment [14] for wastewater treatment plants with PE < 2000. In addition, the paper presents the effects of wastewater treatment to reduce biogens. The best quality of outflow was reached by outflows from constructed wetland treatment plants. None of the observed objects fulfilled the requirements in terms of allowable concentrations for total suspension. The most effective were objects operating in technology of “constructed wetland”.


2006 ◽  
Vol 54 (10) ◽  
pp. 79-86 ◽  
Author(s):  
G. Wandl ◽  
H. Kroiss ◽  
K. Svardal

Two-stage activated sludge plants succeed in stable treatment efficiency concerning carbon removal and nitrification with far less reactor tank volume than conventional single stage systems. In case of large treatment plants this fact is of great economic relevance. Because of the very small specific volume of these two-stage treatment plants in comparison with low loaded single-stage plants, internal cycles have to be applied to ensure sufficient nitrogen removal. Due to these internal cycles two stage activated sludge plants offer many possibilities in terms of process management which results in new process optimisation procedures as compared to conventional single-stage nutrient removal treatment plants. The proposed extension concept for the Main Treatment Plant of Vienna was validated with pilot plant investigations especially with regard to nitrogen removal where it proved to comply with the legal requirements. The operation of the treatment plant can easily be adapted to changes in temperature and sludge volume index occurring in full scale practice. Sludge retention time and aerobic volume in the second stage are controlled in order to secure sufficient nitrification capacity and to optimise nitrogen removal by means of the variation of the loading conditions for the two stages. The investigations confirmed that the specific two-stage activated sludge concept applied in Vienna is an economically advantageous alternative for large wastewater treatment plants with stringent requirements for nitrification and nutrient removal.


2006 ◽  
Vol 69 (1) ◽  
pp. 185-190 ◽  
Author(s):  
HIPÓLITO GÓMEZ-COUSO ◽  
FERNANDO MÉNDEZ-HERMIDA ◽  
JOSÉ ANTONIO CASTRO-HERMIDA ◽  
ELVIRA ARES-MAZÉS

Cryptosporidium contamination was evaluated in areas in Galicia (northwestern Spain) where bivalve molluscs are harvested. Galicia is the main mussel-producing region in Europe. Data were collected on water contamination of effluents that are discharged into these areas. Cryptosporidium spp. were detected by immunofluorescence microscopy and molecular methods in 71% of the river water samples (n = 7), 64% of raw sewage samples (n = 11), 50% of effluents from wastewater treatment plants (n = 16), and 29.3% of the mussel samples (Mytilus galloprovincialis, n = 184). Cryptosporidium parvum was identified in all samples of contaminated mussels, Cryptosporidium muris was found in three samples of effluent from wastewater treatment plants, and Cryptosporidium baileyi was found in a sample of raw sewage. Further studies are needed to determine the parasitological quality of water in these shellfish harvesting and recreational areas. Cryptosporidium could be a public health risk from consumption of raw or undercooked contaminated molluscs and use of contaminated waters for recreational purposes.


2020 ◽  
Vol 180 ◽  
pp. 04013
Author(s):  
Fanel-Viorel Panaitescu ◽  
Mariana Panaitescu ◽  
Nicolaie Ion

In order to reduce the emissions produced by the operational flow of a wastewater treatment plant, regardless of whether they are located in urban or rural areas, the quality of air must be analyzed. For this reason, the Constanta Nord treatment plant was chosen as a study location. This is near the Mamaia resort and does not fall within the recommended sanitary protection norms, according to NP-032-1999 (at least 300 m from the last house). Therefore, it was necessary to take measures to reduce the repellent gases generated in the neighborhood of wastewater treatment plants. The solution is in attention of all wastewater treatment plants from the world because this depend on operational flux management and health of population.The research consists of: description of the technological flow of the treatment plant and in particular of the deodorizing installation of the contaminated air, choosing a work scenario for a day with 2 shifts per hour, respectively 6 shifts per hour, the air flow needed to treat the vitiated air (the deodorization plant components) and the efficiency of the regulation system from the point of view of energy consumption. Also, possible leakage of dangerous gases into the atmospheric air was monitored (H2S, Cl2, CO), taking into account the fact that in the immediate vicinity there is the Mamaia resort, the student housing and rural locations Palazu and Mamaia village.


2020 ◽  
Vol 8 (1) ◽  
pp. 63
Author(s):  
Ni Nyoman Nepi Marleni ◽  
Ristie Ermawati ◽  
Nitis Aruming Firdaus

<span>The water demands for agricultural purposes are increasing along with the population growth. Unfortunately, the water source is not sufficiently available nowadays. Furthermore, the quality of available water is more deteriorated due to the contamination from many sources such as households, industrial areas and other activities. Water board Scheldestromen handles 16 wastewater treatment plants located in Province of Zeeland in The Netherlands. The total production of treated effluent water from 16 wastewater treatment plants is 50 million annually. Quality of the effluent is relatively good, however, some potential risks related to the number of pathogenic microorganism and some trace metals are still there. The treated effluent is mostly discharged to river near to the treatment plant. The high amount of effluent discharge would potentially to be re-used for fulfill the demand for agricultural water. Therefore, this study aims to evaluate the feasibility of treated effluent from one of Walcheren wastewater treatment plants located in Ritthem, Province of Zeeland.</span><span>This study uses the method of Multi Criteria Analysis (MCA) for looking the best way to re-use the effluent for agricultural purposes. The MCA questionnaire was developed based on the thorough literature review of effluent reuse. There are 6 criteria that need to be weighted and 6 scenario alternatives that need to be scored for the MCA questionnaire. The result show that the effluent water contained pathogenic bacteria (E.Coli) and some trace metals (Ni and Cu) more than suggested by FAO standard. Hence the most preferred technology is combination between closed conduits and UV system, with weighted score 0.78 while others had less weighted score compared to the selected one</span>


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Barbara Wodecka ◽  
Jakub Drewnowski ◽  
Anita Białek ◽  
Ewa Łazuka ◽  
Joanna Szulżyk-Cieplak

One of the important factors determining the biochemical processes in bioreactors is the quality of the wastewater inflow to the wastewater treatment plant (WWTP). Information on the quality of wastewater, sufficiently in advance, makes it possible to properly select bioreactor settings to obtain optimal process conditions. This paper presents the use of classification models to predict the variability of wastewater quality at the inflow to wastewater treatment plants, the values of which depend only on the amount of inflowing wastewater. The methodology of an expert system to predict selected indicators of wastewater quality at the inflow to the treatment plant (biochemical oxygen demand, chemical oxygen demand, total suspended solids, and ammonium nitrogen) on the example of a selected WWTP—Sitkówka Nowiny, was presented. In the considered system concept, a division of the values of measured wastewater quality indices into lower (reduced values of indicators in relation to average), average (typical and most common values), and upper (increased values) were adopted. On the basis of the calculations performed, it was found that the values of the selected wastewater quality indicators can be identified with sufficient accuracy by means of the determined statistical models based on the support vector machines and boosted trees methods.


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