Biomedical subjects

J Colprim

Publications and source records attributed to J Colprim.

7 recordsLinked to original sources

PubMed2006

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

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.

Bioreactors↗

PubMed2006

An on-line optimisation of a SBR cycle for carbon and nitrogen removal based on on-line pH and Our: the role of dissolved oxygen control.

A pilot plant sequencing batch reactor (SBR) was applied in a wastewater treatment plant treating urban wastewater focused on carbon and nitrogen removal. From an initial predefined step-feed cycle definition, the evolution of the on-line monitored pH and calculated oxygen uptake rate (OUR) were analysed in terms of knowledge extraction. First, the aerobic phases of the SBR cycle were operated using an On/Off dissolved oxygen (DO) control strategy that concluded with a sinusoidal pH profile that made detecting the "ammonia valley" difficult. After changing to fuzzy logic control of the dissolved oxygen and by adding an air flow meter to the pilot plant, the pH evolution and on-line calculated OUR showed a clearer trend during the aerobic phases. Finally, a proposed algorithm for adjusting the aerobic phases of the SBR for carbon and ammonia removal is presented and discussed.

Aerobiosis↗

PubMed2005

Energy saving in a wastewater treatment process: an application of fuzzy logic control.

Many uncertain factors affect the operation of Wastewater Treatment Plants. Due to the complexity of biological wastewater treatment processes, classical methods show significant difficulties when trying to control them automatically. Consequently soft computing techniques and, specifically, fuzzy logic appears to be a good candidate for controlling these ill-defined, time-varying and non-linear systems. This paper describes the development and implementation of a Fuzzy Logic Controller to regulate the aeration in the Taradell Wastewater Treatment Plant. The main goal of this control process is to save energy without decreasing the quality of the effluent discharged. The fuzzy controller integrates the information coming from two different signals: the Dissolved Oxygen and Oxidation-Reduction Potential values. The simulation results proved that fuzzy logic is a good tool for controlling the aeration of the wastewater treatment plant. The results obtained show that energy savings of more than 10% can be achieved using aeration fuzzy control and at the same time still keeping the good removal levels.

Conservation of Energy Resources↗

PubMed2004

Wastewater nitrogen removal in Sbrs, applying a step-feed strategy: from lab-scale to pilot-plant operation.

One of the problems of nitrogen removal from wastewater when applying sequencing batch reactor (SBR) technology, is the specific use of organic matter for denitrification purposes. Since easily biodegradable organic matter is rapidly consumed under aerobic or anoxic conditions (i.e. aerobic oxidation or anoxic denitrification, respectively), it is an important factor to consider when scaling up SBRs from the laboratory to real plant operation. In this paper, we present the results obtained in relation to scaling up reactors from lab-scale to pilot-plant scale, treating real wastewater from two different locations: the laboratory and in situ, respectively. In order to make using easily biodegradable organic matter more efficient, the filling phases of SBR cycles were adjusted according to a step-feed strategy composed of 6 anoxic-aerobic events. Feeding only occurred during anoxic phases. The results obtained demonstrated that the methodology may be useful in treating real wastewater with high carbon and nitrogen variations, as it always kept effluent levels lower than the official standards require (effluent total COD lower than 125 mg COD/L and effluent Total Nitrogen lower than 15 mg N/L).

Aerobiosis↗

PubMed2003

Textile dyeing wastewater treatment in a sequencing batch reactor system.

This study was undertaken to examine the feasibility of treating biologically textile wastewater for organic carbon removal. The study was conducted over a lab scale SBR equipped with an in-house developed data acquisition and control software. From monitored operation of SBR and dissolved oxygen values, together with a simple compressed air ON/OFF control scheme, on-line Oxygen Uptake Rate (OUR) profiles during aerobic reaction periods were obtained. Due to the high variability of wastewater characteristics, periodical analyses of textile wastewater were conducted and thus characterized for pH, conductivity, total and volatile solids, COD, ammonia, and TKN. After an initial period of activated sludge adaptation to textile wastewater, the SBR was operated at step-feed strategy to reduce the effluent biodegradable matter presents in the wastewater by SBR water change ratio modification and feeding strategy.

Automation↗

PubMed2003

Enhancing biological nitrogen removal in a small wastewater treatment plant by regulating the air supply.

Most of the small wastewater treatment plants in Catalonia were not designed to remove nutrients. However, the large safety margins built into their original engineering design has meant that, in many cases, it has been possible to remove part of the nitrogen without being controlled. This paper focuses on the practical experience carried out in one of these facilities, the Bisbal wastewater treatment plant, aimed at enhancing the biological nitrogen removal using simple, low-cost, easy-to-operate measurement and control. The control strategy, which is based on air supply regulation, was previously designed using simulation studies. A dissolved oxygen monitoring system was installed into the facility, while nitrogen concentrations were analysed every day. Optimal dissolved oxygen profiles in the oxidation ditch were identified, while the air supply strategy was modified according to the variations in the influent.

Air↗

PubMed2002

A hybrid supervisory system to support WWTP operation: implementation and validation.

Integrated operation of Wastewater Treatment Plants is still far from being solved. A reasonable proposal should link advanced and robust control algorithms to some knowledge-based techniques, allocating the detailed engineering to numerical computations, while delegating the logical analysis and reasoning to supervisory intelligent systems. This paper describes the development and implementation of a knowledge-based Hybrid Supervisory System to support the operation of a real Wastewater Treatment Plant. The system integrates different reasoning modules, overcoming the limitations in the use of each single technique, while providing an agent based architecture with additional modularity and independence. It is structured into three separated levels: data gathering, diagnosis, and decision support. The different tasks of the system are performed in a seven-step cycle: data gathering and update, diagnosis, supervision, prediction, communication, actuation, and evaluation phase. In spite of certain reservations of the scientific community about the use of these techniques, the system is successfully performing real-time support to the operation of the Granollers facility since September 1999. Results of the first four-month validation period are shown and discussed. An example of the system behavior is also shown in the paper. The conclusions indicate the key steps which are necessary to transfer the system to another facility.

Algorithms↗