scholarly journals Measurement of activated sludge particle diameters using laser diffraction method / Pomiary średnicy cząstek osadu czynnego za pomocą metody dyfrakcji laserowej

2012 ◽  
Vol 19 (4) ◽  
pp. 597-608 ◽  
Author(s):  
Andrzej Bieganowski ◽  
Grzegorz Łagód ◽  
Magdalena Ryżak ◽  
Agnieszka Montusiewicz ◽  
Mariola Chomczyńska ◽  
...  

Abstract The paper presents a study on the possibility of using the laser diffraction method for measuring the size of the activated sludge particles. Susceptibility of the particles to mechanical disintegration, dependent on the programmed value of stirring intensity, was observed (stirring was caused by required dynamic flow of analysed suspension through the measurement unit). According to the conclusions presented in this paper, it may be assumed that the laser diffraction method can be applied for measurement of activated sludge particle diameters under the following conditions: 1) the size of activated sludge particles measured by the laser diffraction method is not a real value, but after standardisation of measurement conditions can be treated as a parameter describing the sludge; 2) the particle diameters of activated sludge should be stabilised before the measurement, eg by mixing in the measurement unit or by ultrasound waves application.

Author(s):  
S. Cazares ◽  
J. A. Barrios ◽  
C. Maya ◽  
G. Velásquez ◽  
M. Pérez ◽  
...  

Abstract An important physical property in environmental samples is particle size distribution. Several processes exist to measure particle diameter, including change in electrical resistance, blocking of light, the fractionation of field flow and laser diffraction (these being the most commonly used). However, their use requires expensive and complex equipment. Therefore, a Digital Microscopic Imaging Application (DMIA) method was developed adapting the algorithms used in the Helminth Egg Automatic Detector (HEAD) software coupled with a Neural Network (NN) and Bayesian algorithms. This allowed the determination of particle size distribution in samples of waste activated sludge (WAS), recirculated sludge (RCS), and pretreated sludge (PTS). The recirculation and electro-oxidation pre-treatment processes showed an effect in increasing the degree of solubilization (DS), decreasing particle size and breakage factor with ranges between 44.29%, and 31.89%. Together with a final NN calibration process, it was possible to compare results. For example, the 90th percentile of Equivalent Diameter (ED) value obtained by the DMIA with the corresponding result for the laser diffraction method. DMIA values: 228.76 μm (WAS), 111.18 μm (RCS), and 84.45 μm (PTS). DMIA processing has advantages in terms of reducing complexity, cost and time, and offers an alternative to the laser diffraction method.


2021 ◽  
Vol 211 ◽  
pp. 105023
Author(s):  
C. Polakowski ◽  
A. Sochan ◽  
M. Ryżak ◽  
M. Beczek ◽  
R. Mazur ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 465
Author(s):  
Cezary Polakowski ◽  
Magdalena Ryżak ◽  
Agata Sochan ◽  
Michał Beczek ◽  
Rafał Mazur ◽  
...  

Particle size distribution is an important soil parameter—therefore precise measurement of this characteristic is essential. The application of the widely used laser diffraction method for soil analysis continues to be a subject of debate. The precision of this method, proven on homogeneous samples, has been implicitly extended to soil analyses, but this has not been sufficiently well confirmed in the literature thus far. The aim of this study is to supplement the information available on the precision of the method in terms of reproducibility of soil measurement and whether the reproducibility of soil measurement is characterized by a normal distribution. To estimate the reproducibility of the laser diffraction method, thirteen various soil samples were characterized, and results were analysed statistically. The coefficient of variation acquired was lowest (3.44%) for silt and highest for sand (23.28%). Five of the thirteen tested samples were characterized by a normal distribution. The fraction content of eight samples was not characterized by normal distribution, but the extent of this phenomenon varied between soils. Although the laser diffraction method is repeatable, the measurement of soil particle size distribution can have limited reproducibility. The main cause seems to be small amounts of sand particles. The error can be amplified by the construction of the dispersion unit. Non-parametric statistical tests should be used by default for soil laser diffraction method analysis.


2001 ◽  
Vol 14 (1) ◽  
pp. 107-114 ◽  
Author(s):  
L. Vecellio None ◽  
D. Grimbert ◽  
M.H. Becquemin ◽  
E. Boissinot ◽  
A. Le Pape ◽  
...  

2017 ◽  
Vol 17 (1) ◽  
pp. 27-30
Author(s):  
R. Dańko

Abstract The results of investigations of the influence of the matrix grain sizes on properties of cores made by the blowing method are presented in the hereby paper. Five kinds of matrices, differing in grain size compositions, determined by the laser diffraction method in the Analysette 22NanoTec device, were applied in investigations. Individual kinds of matrices were used for making core sands in the Cordis technology. From these sands the shaped elements, for determining the apparent density of compacted sands and their bending strength, were made by the blowing method. The shaped elements (cores) were made at shooting pressures being 3, 4 and 5 atn. The bending strength of samples were determined directly after their preparation and after the storing time of 1 hour.


2008 ◽  
Vol 53 (No. 1) ◽  
pp. 34-38 ◽  
Author(s):  
M. Ryzak ◽  
A. Bieganowski ◽  
R.T. Walczak

Particle size distribution affects many physical soil properties and processes taking place in soil. There are many methods to determine the particle size distribution. The most frequently used are the sieve, sieve-pipette and sedimentation methods. Technological progress in electronics permitted a wide use of new methods of particle size distribution measurement in soil, e.g. the laser diffraction method. A comparison of particle size distribution obtained with the universally used areometer method (Cassagrande, modified by Prószynski) with results from the laser diffraction method for soil material received from grey-brown podzolic soil is presented in this work. The largest differences between the results were obtained for the smallest fraction determined with the areometer and laser diffraction methods. In a majority of other cases the slopes of interpolated straight lines were contained within the range of 0.81 ÷ 1.09.


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