scholarly journals Selection of methods for activated sludge bulking control using a molecular biology technique combined with respirometric tests

2016 ◽  
Vol 3 ◽  
pp. 187-193
Author(s):  
Aleksandra Miłobędzka ◽  
Adam Muszyński
Keyword(s):  
Molecular Biology ◽  
Activated Sludge ◽  
Molecular Biology Technique ◽  
Sludge Bulking ◽  
Selection Of

scholarly journals Soft Sensor Application in Identification of the Activated Sludge Bulking Considering the Technological and Economical Aspects of Smart Systems Functioning

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1941 ◽  
Author(s):  
Bartosz Szeląg ◽  
Jakub Drewnowski ◽  
Grzegorz Łagód ◽  
Dariusz Majerek ◽  
Ewa Dacewicz ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Smart Cities ◽  
Treatment Plant ◽  
Soft Sensor ◽  
Support Vector ◽  
Optimal Method ◽  
Independent Variables ◽  
Sludge Bulking ◽  
Selection Of

The paper presented the methodology for the construction of a soft sensor used for activated sludge bulking identification. Devising such solutions fits within the current trends and development of a smart system and infrastructure within smart cities. In order to optimize the selection of the data-mining method depending on the data collected within a wastewater treatment plant (WWTP), a number of methods were considered, including: artificial neural networks, support vector machines, random forests, boosted trees, and logistic regression. The analysis conducted sought the combinations of independent variables for which the devised soft sensor is characterized with high accuracy and at a relatively low cost of determination. With the measurement results pertaining to the quantity and quality of wastewater as well as the temperature in the activated sludge chambers, a good fit can be achieved with the boosted trees method. In order to simplify the selection of an optimal method for the identification of activated sludge bulking depending on the model requirements and the data collected within the WWTP, an original system of weight estimation was proposed, enabling a reduction in the number of independent variables in a model—quantity and quality of wastewater, operational parameters, and the cost of conducting measurements.

Control of activated sludge bulking by operating clarifiers in a series

1998 ◽  
Vol 38 (8-9) ◽  
pp. 1-8 ◽  
Author(s):  
Youngchul Kim ◽  
Wesley O. Pipes ◽  
Paul-Gene Chung
Keyword(s):  
Activated Sludge ◽  
Settling Tank ◽  
Pharmaceutical Manufacturing ◽  
Selection Function ◽  
Manufacturing Plant ◽  
Sludge Bulking ◽  
In Series ◽  
Scale Experiment ◽  
Filament Content ◽  
Selection Of

A full scale experiment with an activated sludge process in a pharmaceutical manufacturing plant showed that the operation of two settling tanks in series, with the first tank full of sludge, resulted in selection of sludge particles which had a lower than average filament content for retention in the process. Series operation of the two clarifiers was very successful in controlling sludge bulking. The functioning of the settling tanks as selectors of sludge particles which settle and thicken well has not been considered to any great extent. Two laboratory-scale activated sludge plants fed with an artificial wastewater were operated to explore this selection function further. The SVI values were measured and assessed. At the start of operation, the SVI was about 60–80 ml/g in both of the parallel and the series plants. After eight days of the operation, the SVI started to increase rapidly in the parallel plant, and in twenty days of operation, the averaged values of SVI were 163 ml/g and 116 ml/g for the parallel and the series plants, respectively. On day 38, MLSS from two aeration tanks were interchanged. In a few days after that interchange, the SVI values in the parallel, which was originally in the series mode, rapidly increased from 130 ml/g to more than 350 ml/g(SV30 = 930 ml/g). This experiment clearly supports the hypothesis of a microorganism selection function of the settling tank and also corresponds to the results obtained from the field study.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

Filament content threshold for activated sludge bulking: Artifact or reality?

2007 ◽  
Vol 41 (19) ◽  
pp. 4349-4356 ◽  
Author(s):  
Andrew J. Schuler ◽  
David Jassby
Keyword(s):  
Activated Sludge ◽  
Sludge Bulking ◽  
Filament Content

Towards a Comprehensive Model of Activated Sludge Bulking and Foaming

1992 ◽  
Vol 25 (6) ◽  
pp. 215-230 ◽  
Author(s):  
David Jenkins
Keyword(s):  
Activated Sludge ◽  
Comprehensive Model ◽  
Activated Sludge Model ◽  
Sludge Bulking ◽  
Physiological Properties

The physiological properties of filamentous and floc-forming microorganisms found in activated sludge are reviewed. From this review four model microorganisms - two floc formers and two filamentous organisms - are proposed for use in an activated sludge model that predicts activated sludge “quality”.

Rule based control of a periodic activated sludge process

1998 ◽  
Vol 38 (3) ◽  
pp. 281-289 ◽  
Author(s):  
S. Isaacs ◽  
D. Thornberg
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Control Strategy ◽  
Periodic Operation ◽  
Rule Based ◽  
Criterion Functions ◽  
Strategy Performance ◽  
Working Region ◽  
And Control ◽  
Selection Of

A rule based control strategy for automatically adjusting phase lengths and aeration intensity for an activated sludge nutrient removal process based on a periodic operation is examined using simulations based on the Activated Sludge Model No. 1. The strategy is based on four criterion functions, two which determine the switching of the roles of two nitrifying/denitrifying reactors and two which adjust the dissolved oxygen setpoint levels in the two reactors as functions of ammonia and nitrate concentrations. Trajectory plots of reactor concentrations in the ammonia-nitrate plane are shown to be a useful means of visualizing process and control performance. Together, the trajectories from a working region in the ammonia-nitrate plane, the size and location of which can to some extent be predetermined by selection of the criterion functions. The presented results include the influence of one of the criterion functions on control strategy performance, how an incompatibility between two criterion functions can lead to unsymmetric reactor loading, and the effect of allowing simultaneous nitrification and denitrification during nitrifying periods by reducing the dissolved oxygen level as ammonia is consumed.

scholarly journals Decrease in the Hospital Stay of Neonates with Suspected Nosocomial Sepsis with the Use of a Molecular Biology Technique

2019 ◽  
Vol 07 (03) ◽  
pp. 44-51
Author(s):  
Jesús Reyna-Figueroa ◽  
María Fernanda Rodríguez-Sánchez ◽  
Pilar Miyoko Martínez Matsumoto ◽  
Federico Javier Ortiz-Ibarra ◽  
Ana Elena Limón-Rojas
Keyword(s):  
Molecular Biology ◽  
Hospital Stay ◽  
Molecular Biology Technique ◽  
Nosocomial Sepsis
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