Comparison of soil texture determined by two dispersion units of Mastersizer 2000

Abstract

A b s t r a c t. The comparison of particle size distributions measured by sedimentation methods and laser diffraction shows the underestimation of the fine (clay) fraction. This is attributed mainly to the shape of clay particles being different than spherical. The objective of this study was to demonstrate differences in the results of particle size distributions of soils determined with the method of laser diffraction using two different dispersion units of the Malvern Mastersizer 2000.K e y w o r d s: particle size distributions, sedimentation, laser diffraction, Mastersizer 2000 INTRODUCTIONParticle size distribution (PSD) of soils is one of the fundamental parameters permamently used in soil science (Brzeziñska et al., 2011; Joó et al., 2010; Nosalewicz and Nosalewicz, 2011; S³awiñski et al., 2011; Tóth et al., 2009). More and more often the determinations of that parameter is made with the use of the method of laser diffraction (Blott and Pye, 2006; Pye and Blott, 2004; Sperazza et al., 2004). The method consists in measuring the intensity of laser light scattered on the particles measured. The intensity of scattered light depends on the size of the particles in the measurement system. The smaller the particle, the greater the angle at which the light is scattered/refracted.The method of laser diffraction has been compared many times with the earlier methods of PSD determinationthe sedimentation methods (Arriaga et al., 2006; Beuselinck et al., 1998; Ry¿ak and Bieganowski, 2010; Tauber et al., 2008). In certain of such reports one can encounter information about underestimation of the fine (clay) fraction content in measurements performed with the method of laser diffraction as compared to the sedimentation methods (Beuselinck et al., 1998; Eshel et al., 2004; Konert and Vanderberghe, 1997). The underestimation of the clay fraction content is attributed mainly to the shape of clay particles being different than spherical (Konert and Vendenberghe, 1997). Those authors pointed out that the divergent results might be also related to problems with the selection of optical parameters for the clay fraction (Eshel et al., 2004) or with the limited measurement range, especially of the older types of apparatus (Beuselinck et al., 1998).Apart from the above potential causes of the underestimated clay content in soils studied careful analysis of the literature on the determination of PSD with the method of laser diffraction leads also to further conclusions. One of the more important reasons for the lack of comparability of results lies in the use of laser diffractometers of various manufacturers or various models (generations) of equipment of this type from a single manufacturer. Another problem is the frequent lack of information -in research publications -on the type/model of apparatus used and/or on its equipment.The objective of this study was to demonstrate differences in the results of PSD of soils determined with the method of laser diffraction using two different dispersion units of the Malvern Masters...

Kinetics of methane oxidation in selected mineral soils

“…of the pump and 700 r.p.m. of stirrer (Sochan et al, 2012). Total organic carbon (C org ) was determined by TOC-VCPH analyzer (Shimadzu, Japan), and soil pH was measured in 1 mol KCl (1:2.5 mass) after 24-h stabilization at room temperature.…”

Impact of optical indices on particle size distribution of activated sludge measured by laser diffraction method

“…The degree of the disintegration will be related to the energy of stirring. In turn, the energy of stirring will depend on the construction of the dispersion unit of the diffractometer (including the design of the stirrer and pump) and on the speed of stirring and pumping [38]. Therefore, the method can be used for comparison of results obtained in different laboratories only when measurements are done using the same device and measurement procedure.…”

A talajok mechanikai összetétel vizsgálata pipettás ülepítéses módszerrel: a hazai és a nemzetközi szabvány szerinti eljárások összehasonlítása és konverziója

“…Ez általában a talajszuszpenzió különböző ideig történő rázatását vagy keverését jelenti különböző típusú eszközökkel. Az ultrahangos diszpergálást leginkább a lézerdiffrakciós MÖ méréseknél alkalmazzák, az ülepítéses módszereknél ritkábban használatosak (GENRICH & BREMNER, 1972;SOCHAN et al, 2012;.…”