Simultaneous determination of activated sludge floc size distribution by different techniques

2004 ◽  
Vol 50 (12) ◽  
pp. 39-46 ◽  
Author(s):  
R. Govoreanu ◽  
H. Saveyn ◽  
P. Van der Meeren ◽  
P.A. Vanrolleghem
Keyword(s):  
Image Analysis ◽  
Activated Sludge ◽  
Size Distribution ◽  
Bimodal Distribution ◽  
Pilot Scale ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Floc Size ◽  
In Series ◽  
Log Normal

The activated sludge floc size distribution (FSD) is investigated by using different techniques and the results are compared against each other in order to gain insight into the FSD characteristics, as well as to detect the limitations of each measurement technique. The experimental set-up consisted of three devices coupled in series: a MastersizerS, an automated image analysis system (IMAN) and a CIS-100. The latter instrument has two measurement channels, based on time of transition (TOT), and image analysis (SHAPE) principles. In order to minimise the variability between successive measurements, the activated sludge samples collected from a pilot-scale SBR were flocculated until steady state was achieved. The results show that the MastersizerS and SHAPE devices yield similar volume weighted FSD. In contrast, the IMAN overestimated the floc size and TOT frequently showed a bimodal distribution. The number distributions from TOT and SHAPE were in agreement, while those generated by the MastersizerS were mainly located in the submicron range and those of IMAN corresponded to larger sizes. The experimental distributions show a good fit to the log-normal model. It is shown that the measurement principle is of utmost importance and results transformation may lead to data misinterpretation.

A methodological approach for direct quantification of the activated sludge floc size distribution by using different techniques

2009 ◽  
Vol 60 (7) ◽  
pp. 1857-1867 ◽  
Author(s):  
R. Govoreanu ◽  
H. Saveyn ◽  
P. Van der Meeren ◽  
I. Nopens ◽  
P. A. Vanrolleghem
Keyword(s):  
Activated Sludge ◽  
Size Distribution ◽  
Methodological Approach ◽  
Measurement Techniques ◽  
Spherical Particles ◽  
Experimental Conditions ◽  
Detection Range ◽  
Floc Size ◽  
In Series ◽  
High Concentrations

The activated sludge floc size distribution (FSD) is investigated by using different measurement techniques in order to gain insight in FSD assessment as well as to detect the strengths and limitations of each technique. A second objective was to determine the experimental conditions that allow a representative and accurate measurement of activated sludge floc size distributions. Laser diffraction, Time Of Transition (TOT) and Dynamic Image Analysis (DIA) devices were connected in series. The sample dilution liquid, the dilution factor and hydraulic flow conditions avoiding flocculation proved to be important. All methods had certain advantages and limitations. The MastersizerS has a broader dynamic size range and provides accurate results at high concentrations. However, it suffers from an imprecise evaluation of small size flocs and is susceptible to particle shape effects. TOT suffers less from size overestimation for non-spherical particles. However, care should be taken with the settings of the transparency check. Being primarily a counting technique, DIA suffers from a limited size detection range but is an excellent technique for process visualization. All evaluated techniques turned out to be reliable methods to quantify the floc size distribution. Selection of a certain method depends on the purpose of the measurement.

Application of Image Analysis System for Study of Activated Sludge Flocs

1986 ◽  
Vol 21 (1) ◽  
pp. 130-140 ◽  
Author(s):  
Da-hong Li ◽  
J. J. Ganczarczyk
Keyword(s):  
Image Analysis ◽  
Activated Sludge ◽  
Statistical Processing ◽  
Equivalent Diameter ◽  
Image Analysis System ◽  
Sectional Area ◽  
Cross Sectional ◽  
Computerized Image Analysis ◽  
Sludge Flocs ◽  
Analysis System

Abstract The computerized image analysis system has been successfully used for determination and statistical processing of the following geometric characteristics of activated sludge flocs: longest dimension, breadth, equivalent diameter, cross-sectional area, perimeter, elongation, and circularity. These parameters could be effectively and precisely determined by the system applied. In addition, the studied method, as compared to direct microscope observation and photography floc-sizing methods, was found to be more accurate, less time-consuming, and less dependent on the investigators.

Validation of a new image analysis procedure for quantifying filamentous bacteria in activated sludge

2014 ◽  
Vol 70 (6) ◽  
pp. 955-963 ◽  
Author(s):  
Ewa Liwarska-Bizukojc ◽  
Marcin Bizukojc ◽  
Olga Andrzejczak
Keyword(s):  
Image Processing ◽  
Image Analysis ◽  
Activated Sludge ◽  
Analysis Procedure ◽  
Automated Image Analysis ◽  
Filamentous Bacteria ◽  
Image Processing And Analysis ◽  
Manual Counting ◽  
Analysis Application ◽  
Activated Sludge Systems

Quantification of filamentous bacteria in activated sludge systems can be made by manual counting under a microscope or by the application of various automated image analysis procedures. The latter has been significantly developed in the last two decades. In this work a new method based upon automated image analysis techniques was elaborated and presented. It consisted of three stages: (a) Neisser staining, (b) grabbing of microscopic images, and (c) digital image processing and analysis. This automated image analysis procedure possessed the features of novelty. It simultaneously delivered data about aggregates and filaments in an individual calculation routine, which is seldom met in the procedures described in the literature so far. What is more important, the macroprogram performing image processing and calculation of morphological parameters was written in the same software which was used for grabbing of images. Previously published procedures required using two different types of software, one for image grabbing and another one for image processing and analysis. Application of this new procedure for the quantification of filamentous bacteria in the full-scale as well as laboratory activated sludge systems proved that it was simple, fast and delivered reliable results.

scholarly journals Assessing Small Bowel Stricturing and Morphology in Crohn’s Disease Using Semi-automated Image Analysis

2019 ◽  
Vol 26 (5) ◽  
pp. 734-742 ◽  
Author(s):  
Ryan W Stidham ◽  
Binu Enchakalody ◽  
Akbar K Waljee ◽  
Peter D R Higgins ◽  
Stewart C Wang ◽  
...  
Keyword(s):  
Image Analysis ◽  
Crohn’S Disease ◽  
Small Bowel ◽  
Crohn's Disease ◽  
Structural Damage ◽  
Clinical Decision Making ◽  
Tertiary Care ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Ct Enterography

Abstract Background Evaluating structural damage using imaging is essential for the evaluation of small intestinal Crohn’s disease (CD), but it is limited by potential interobserver variation. We compared the agreement of enterography-based bowel damage measurements collected by experienced radiologists and a semi-automated image analysis system. Methods Patients with small bowel CD undergoing a CT-enterography (CTE) between 2011 and 2017 in a tertiary care setting were retrospectively reviewed. CT-enterography studies were reviewed by 2 experienced radiologists and separately underwent automated computer image analysis using bowel measurement software. Measurements included maximum bowel wall thickness (BWT-max), maximum bowel dilation (DIL-max), minimum lumen diameter (LUM-min), and the presence of a stricture. Measurement correlation coefficients and paired t tests were used to compare individual operator measurements. Multivariate regression was used to model identification of strictures using semi-automated measures. Results In 138 studies, the correlation between radiologists and semi-automated measures were similar for BWT-max (r = 0.724, 0.702), DIL-max (r = 0.812, 0.748), and LUM-min (r = 0.428, 0.381), respectively. Mean absolute measurement difference between semi-automated and radiologist measures were no different from the mean difference between paired radiologists for BWT-max (1.26 mm vs 1.12 mm, P = 0.857), DIL-max (2.78 mm vs 2.67 mm, P = 0.557), and LUM-min (0.54 mm vs 0.41 mm, P = 0.596). Finally, models of radiologist-defined intestinal strictures using automatically acquired measurements had an accuracy of 87.6%. Conclusion Structural bowel damage measurements collected by semi-automated approaches are comparable to those of experienced radiologists. Radiomic measures of CD will become an important new data source powering clinical decision-making, patient-phenotyping, and assisting radiologists in reporting objective measures of disease status.

Automated image analysis of Euglena gracilis Klebs (Euglenophyta) for measuring sublethal effects of three model contaminants

2012 ◽  
Vol 66 (8) ◽  
pp. 1708-1715 ◽  
Author(s):  
I. Netto ◽  
V. Bostan ◽  
L. McCarthy ◽  
A. Laursen ◽  
K. Gilbride ◽  
...  
Keyword(s):  
Image Analysis ◽  
Euglena Gracilis ◽  
Cell Shape ◽  
Early Warning Systems ◽  
Visual Observation ◽  
Automated Image Analysis ◽  
Swimming Velocity ◽  
Image Analysis System ◽  
Behavioural Changes ◽  
Analysis System

The short-term impacts of atrazine (herbicide), tributyltin (organometal) and copper on the behaviour of Euglena gracilis Klebs (Euglenophyta) were assessed. First, the ECOTOX automated image analysis system was used, which measured swimming velocity, cell shape, percentage of cells swimming upwards, and randomness of swimming. Next, visual observation by microscopy was used to measure percentage of cell motility and cell shape. Behavioural changes can be used as an indicator of stress in less than 24 h, potentially making them suitable for inclusion in early-warning systems for water quality. Findings indicate that E. gracilis is a very sensitive organism to copper, showing inhibition of motility with visual observation at 0.8 μmol/L within 1 h. The image analysis system was in general less sensitive than visual observation for detecting behavioural changes after incubation in copper. In contrast, after exposure to organic contaminants atrazine and tributyltin, the ECOTOX system detected small changes in the number of cells swimming upwards (antigravitactic behaviour) at higher concentrations.

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