Cleanroom Mats: An Investigation of Particle Removal

1996 ◽  
Vol 39 (4) ◽  
pp. 19-27
Author(s):  
W. Whyte ◽  
T. Shields ◽  
T. Prvan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Removal Efficiency ◽  
Adhesive Strength ◽  
Particle Removal ◽  
High Concentration ◽  
Low Concentration

The variables that influence the particle removal efficiency of cleanroom mats were investigated. The removal efficiency was generally found to be greater if the mat was of a softer type, the particles smaller, the particle size distribution more homogeneous, the distance between the particles greater, and the adhesive strength of the mat surface greater. One application of a mat surface was sufficient to remove a low concentration of similarly sized particles from a surface but it could require up to four mat surfaces to remove a high concentration of heterogeneously sized particles. It was found with heterogeneously sized particles that larger particles were removed first, thus allowing access to the smaller particles which could then be removed. If the mat was soft, it allowed larger particles to sink into it and smaller particles than normal to be picked up.

Tertiary filtration in small wastewater treatment plants

2007 ◽  
Vol 55 (7) ◽  
pp. 219-225 ◽  
Author(s):  
V. Naddeo ◽  
V. Belgiorno
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Wastewater Treatment Plants ◽  
Rotating Disk ◽  
Quality Parameters ◽  
Particle Removal ◽  
Sand Filters ◽  
Filter Performance

Tertiary filtration can be proposed in small wastewater treatment plants with impact on protected water bodies. Rotating disk filters may be adopted, in respect to conventional sand filters, when low availability of space and low investment costs are the prevailing conditions. The overall objective of this research was to evaluate the filtration efficiency of rotating disk filters; to compare effectiveness with traditional sand filters; to analyse thoroughly the importance of particle size distribution in wastewater tertiary filtration. In the experimental activity, conventional wastewater quality parameters were investigated and particle size distribution (PSD) was characterized to discuss the filter effectiveness. The effect of design and operation parameters of tertiary filters were discussed related to particle removal curves derived from particles counts. Analysis of particle size distribution can be very useful to help comprehension of filtration processes, design of filtration treatments and to decide the best measures to improve filter performance.

Effect of Particle Size Distribution and Selective Alcohol Additives for Preparation of High Concentration Coal-Water Slurry

2020 ◽  
Vol 12 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Debadutta Das ◽  
Anupama Routray ◽  
Swetashree Pattanaik ◽  
Pankaj K. Parhi ◽  
Bijnyan R. Das ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Static Stability ◽  
Industrial Applications ◽  
High Concentration ◽  
Oh Groups ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Water Alcohol

Background: The alternative of oil is highly essential in the present context due to the acute shortage of oil as well as increasing demand for it from different public and private sectors. Since 1980, attention has been focused on coal-water slurry as an alternative fuel for the power generation industry and a suitable substitute for oil in several industrial applications. One of the exciting areas in Coal Water Slurry (CWS) is coal–water-alcohol slurry in which different alcohol compound can act as a dispersant for the stabilisation of coal–water slurry. Objective: The objective of this paper is to prepare a high concentration coal–water-alcohol slurry using glycerol, glycol and ethanol as an additive, and different particle size distribution of coal. This will increase the surface activity of the coal thereby, decreasing the viscosity of the slurry. Method: Two bimodal samples are prepared in which coarse particles are (212 μm - 300 μm), (150 μm – 212 μm) and fine particle below 75 μm. Three types of alcohol additive namely glycerol, glycol and ethanol are used as a dispersant. Malvern Particle size analyzer is used to measure the particle size distribution of the coal samples. Rheological study of CWAS was conducted using HAAKE RHEO STRESS 1. Result: From the experiment, it has been concluded that the optimum addition of glycerol in water is taken as 90:10 of water and glycerol ratio because after that, there is no further decrease in the value of viscosity. An optimum value of glycol and ethanol mixed in water was determined and found as in the ratio of 86:14 and 82:18, respectively. Conclusion: From different parameter studies like coal concentration, pH, temperature, apparent viscosity and stability, it has been concluded that coal-water-glycerol slurry is better than other coal water- alcohol slurry. This is because of the presence of more OH- groups in glycerol. The static stability of this coal-water-alcohol slurry exists for the maximum period of 31 days.

Study on Measuring Particle Size Distribution of a Nanodiamond Powder

2013 ◽  
Vol 631-632 ◽  
pp. 73-77 ◽  
Author(s):  
Qi Long Wei ◽  
Yu Tang Meng
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Doppler Frequency ◽  
Diamond Powder ◽  
High Concentration ◽  
Tem Analysis ◽  
Materials Properties ◽  
Pre Treatment ◽  
Dispersing Medium

Particle size distribution (PSD) of a nanodiamond powder in a high concentration suspension was measured by a new dynamic light scattering (DLS) technique based on the Doppler frequency shifting effect. Influence of dispersing pre-treatment, distribution bases and materials’ properties on DLS results was analyzed, and PSD results were validated by TEM analysis. It was found that the optimized ultrasonic dispersing time of the diamond powder in a sodium hexametaphosphate (SHP) solution was about 5 minutes. And median sizes of the nanodiamond powder were 115.6 nm, 53.0 nm and 32.6 nm, based on light intensity, volume and number respectively. PSD results of the nanodiamond based on number accorded well with results from TEM analysis. And PSD results were affected hardly by refractive indices of the diamond and the dispersing medium, while they were affected markedly by viscosity of the medium. It is concluded that this new DLS technique could measure PSD of the nanodiamond powder in high concentration suspensions which has been dispersed properly.

Effect of Filter Media Particle Size Distribution on Filtration Efficiency

1998 ◽  
Vol 33 (4) ◽  
pp. 589-594 ◽  
Author(s):  
F. Amini ◽  
H.V. Truong
Keyword(s):  
Water Quality ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Removal Efficiency ◽  
Scale Model ◽  
Filter Media ◽  
Sand Filter ◽  
Sediment Removal ◽  
Filter Water

Abstract The results of an experimental study of a sand filter water quality model are presented. The model is built to represent an underground confined water quality sand filter structure. Three types of sands, namely fine, medium and coarse, were used to study the effect of filter media particle size distribution on sediment removal efficiency. The results indicated that the sediment removal efficiency for all sand types decreased with time. The use of medium sand provided the scale model filter with the highest sediment removal efficiency. The finding of this study indicates that the media grain size has a measurable effect on the efficiency of the sand filter water quality structure.

scholarly journals Synchronous Acquisition and Analysis of Ultrasonic Spectral Information for the Characterization of Particle Size Distribution

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Nan Jia ◽  
Jianfei Gu ◽  
Huinan Yang ◽  
Mingxu Su
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Volume Fraction ◽  
Ultrasonic Attenuation ◽  
Measurement Methods ◽  
Particle Sizing ◽  
High Concentration ◽  
Unknown Parameters ◽  
Transmission Method

Particle sizing methods have gained considerable attention in the past few decades, but there is still a big challenge in high concentration situations (i.e., volume fraction>10%). However, the ultrasonic spectroscopy technique is a common tool for the noninvasive determination of essential parameters for high concentration systems by analyzing ultrasonic spectra with inversion algorithms, including the particle size distribution (PSD), volume fraction of each phase, and physicochemical properties. For the ultrasonic measurements, proper acquisition and analysis of ultrasonic spectra are becoming significant in order to understand the relationship between the unknown parameters and the ultrasonic spectra. In the work, an experimental setup was provided to synchronously acquire ultrasonic reflection and transmission signals. A series of experiments were performed on silicon-water solutions at volume fractions 8%, 10%, and 12% to obtain the ultrasonic attenuation spectra and ultrasonic phase velocity spectra based on different measurement methods, i.e., the pulse-echo method, reference reflection method, and through-transmission method, respectively. Based on the Epstein-Carhart-Allegra-Hawley (ECAH) forward model, genetic algorithm (GA) and optimum regularization technique (ORT) algorithms were implemented to determine PSD with the measured spectra; the obtained PSD was then compared with the optical microscope method. It revealed that the spectra obtained by different measurement methods showed individual features while the obtained PSD was consistent and the volume median diameters were within a deviation of 10% with GA and ORT algorithms. The differences and characteristics of these three measurement methods for signal acquisition and interpretation were discussed and presented to provide an evaluation and recommendation for ultrasonic particle sizing.

scholarly journals Particle size distribution of airborne particulate matter in Petropavlovsk-Kamchatsky and Yelizovo based on the results of several years of study

2021 ◽  
pp. 66-72
Author(s):  
A. S. Kholodov ◽  
K. Yu. Kirichenko ◽  
K. S. Golokhvast
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Airborne Particulate Matter ◽  
Kamchatka Peninsula ◽  
Airborne Particulate ◽  
High Concentration ◽  
Anthropogenic Aerosols ◽  
Snow Samples

Introduction. Kamchatka Krai is a region with low population density and poorly developed industry. However, in large cities the air quality is degraded due to economic activity. Aim. To study the concentration of airborne particulate matter (in particular, up to 1 µm and up to 10 µm) in Petropavlovsk-Kamchatsky and Yelizovo air and carry out a comparative analysis with the previously obtained results of environmental monitoring of atmospheric suspension.Materials and methods. Airborne particulate matter was studied in snow which was collected during snowfalls to avoid its secondary pollution by anthropogenic aerosols. The melted snow was analyzed on a Fritsch Analysette 22 NanoTech laser particle analyzer (Germany).Results. PM1 particles were found in five snow samples taken in Petropavlovsk-Kamchatsky. The quantity of PM₁₀ is low in all samples, and only in two of six sampled areas it reaches 12%. Compared to the results of previous studies, the concentration of PM1 is at the same level as in previous years, and the content of PM₁₀ has decreased. In samples from Yelizovo, the same trends are observed. Compared to 2018, when a high concentration of PM₁₀ particles was found in almost all samples, reaching 57.2%, there is a trend towards a decrease in the concentration of the potentially hazardous PM fraction.Conclusion. Updated data on the particle size distribution of airborne particulate matter in two cities of the Kamchatka Peninsula were obtained. In the snow samples collected in Petropavlovsk-Kamchatsky and Yelizovo, we found PM₁ and PM₁₀ particles hazardous to human health, although their concentration is generally lower than in previous years of the study. 

Preparation and Adsorption Properties of Fe/Chitosan/Fly Ash Composite

2017 ◽  
Vol 898 ◽  
pp. 1885-1891 ◽  
Author(s):  
Bei Gang Li ◽  
Min Wang
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Gas Adsorption ◽  
Fine Powder ◽  
Adsorption Properties ◽  
Iron Hydroxides ◽  
High Concentration ◽  
Solution Ph

Fly ash (FA), a kind of fine-powder solid waste, was utilized to prepare a novel Fe/chitosan/FA composite (Fe/CTS/FA) by the calcination and solution reaction with chitosan (CTS) and ferric iron. In combination with the adsorption for reactive turquoise blue KN-G (RTB KN-G) and direct sky blue 5B (DSB 5B) dyes, the main conditions of preparation and adsorption of Fe/CTS/FA were investigated. The composite was characterized with SEM, EDS, particle-size distribution and N2-gas adsorption-desorption technology. The results show that: (1) Fe/CTS/FA prepared by calcining FA at 500°C and further mixing reaction with CTS and FeCl3⋅6H2O solution according to the mass ratio of m(FA):m(CTS):m(Fe)=10:1:0.34 has excellent adsorption properties. The amount of adsorption is mainly affected by solution pH and reaches the equilibrium in 60 min for high-concentration RTB KN-G and DSB 5B dye wastewater with adsorption capacities of 892.95 mg/g and 615.65 mg/g, which are 16.28 and 32.56 times larger than those of FA, respectively. (2) The characterization results of Fe/CTS/FA indicate that CTS and iron hydroxides have been successfully loaded on FA. The surface morphology of Fe/CTS/FA is significantly changed, and the particle-size distribution is obviously smaller than that of FA.

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