Determination of soil grain size composition by measuring apparent weight of float submerged in suspension

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1 Int. Agrophy., 2017, 31, doi: /intag Determination o oil grain ie compoition by meauring apparent eight o loat ubmerged in upenion Jaroła Kaubkieic 1 *, Witold Wilceki 2, Tibor Jóe Novák 3, Premyła Woźnicka 1, Kryto Falińki 2, Jery Beloki 2, and Dorota Kaałko 1 1 Intitute o Soil Science and Environment Protection, Wrocła Univerity o Environmental and Lie Science, Grunaldka 53, Wrocła, Poland 2 Arcanum Sp. o.o., Parkoa 6/1, Wrocła, Poland 3 Department o Landcape Protection and Environmental Geography, Univerity o Debrecen, Böörményi út 138,4032, Debrecen, Hungary Received arch 23, 2016; accepted December 13, 2016 A b t r a c t. Texture i one o the mot igniicant phyical propertie o oil. Over the year, everal method o it meauring ere developed. The paper preent a method or determining the particle ie compoition o oil, baed on the eparation o particle in the edimentation proce. Denity o upenion i determined on the bai o apparent eight change o a loat ubmerged in it. The eight o the loat upended on a thin line, at a given depth in the upenion, i meaured ith a enitive pieoelectric dynamometer. The Stoke equation i ued to calculate the content o oil raction ith equivalent diameter in the range o to 0.1 mm. Digital tranmiion o reult rom the dynamometer, the temperature enor and meaurement o the ditance deining the depth o immerion o the loat to the computer enable calculation o particle ie compoition to be perormed automatically. Thi paper preent the reult o meaurement o the particle ie compoition o artiicially generated mixture o ilt and clay. The reult are compared ith reult obtained ith other method (including the laer method). A high level o repeatability o the reult and atiactory compatibility in relation to the reerence pipette method are noted. K e y o r d : edimentation, particle ie compoition, oil upenion denity INTRODUCTION Particle ie compoition i the primary parameter neceary or the evaluation o other oil propertie and or the determination o oil agricultural uitability (Słaińki et al., 2011; Smith, ullin, 1991). A igniicant group o method or it determination are edimentation method developed over the pat 100 year (Allen et al., 1996; Allen, 1997, Ryżak et al., 2009). Their primary objective i to determine the hare o the ma o elected raction o oil. Thee method have been improved over many year (Bieganoki and Walcak, 2004; Gee and Bauder, 1979; Rąa, 1978), and currently, together ith the laer diraction method developed in recent decade (Agraal et al., 1991; Bieganoki and Walcak, 2004; Bieganoki et al., 2010; Singer et al., 1988), are a baic reearch tool (ISO 11277, 1998; Rąa and Ocarak, 2013). The pipette method (SP) i accepted in many countrie a the oicial reerence method or meauring the raction o equivalent diameter le than 63 mm (Allen, 1997; ISO, 1998). It i conidered an accurate method but time-conuming and laboriou (Allen, 1997; Beuenlick et al., 1998; Ryżak et al., 2009), hich limit it ue in ma meaurement. The cited laer diraction method (LD) are characteried by many advantage, among hich the mot important are the peed and repeatability o the analyi and the ide range o the deignated raction. Hoever, a hon in report by many author (Agraval et al., 1991; Allen, 1997; Di Steano et al., 2010; Konert and andenberghe, 1997; Ryżak and Bieganoki, 2010), their dierent phyical principle imply dierent reult rom thoe obtained in edimentation method. All edimentation method are baed on the aumption that oil particle in ater upenion behave according to the Stoke equation hich a applied to oil analyi by Oden (2010). According to the equation, all time or particle ith diameter to depth i proportional to the quare o the diameter. Thi la i atiied by pherical particle that *Correponding author jarola.kaubkieic@up.roc.pl 2017 Intitute o Agrophyic, Polih Academy o Science

2 62 J. KASZUBKIEWICZ et al. comply ith additional condition, hich ill be dicued later in thi paper. The peed o decent o an actual grain may ubtantially dier rom that calculated or pherical particle (Dietrich, 1982; Loth, 2008). The problem o the inluence o particle hape on reult obtained or all method including laer method hould be noted (Ehel et al., 2004; Sochan et al., 2012). LD method eem to be independent o the heterogeneity o the denity o oil particle o variou ie, hich ha an impact on edimentation (Bah et al., 2009). In edimentation method the content o olid phae particle in upenion i meaured, here a a reult o the dierent peed o decent o grain the eparation o oil particle o dierent ie occur. The meaurement i carried out via the evaporation o ater (P) or by meauring the denity o the upenion. eauring the denity o the upenion can be realied uing a Caagrande or Próyńki aerometer (SH) (Komornicki and Jakubiec, 1978; Kovác et al., 2006) or by meaurement o hydrotatic preure that act in the upenion (Kovác et al., 2004; Neme et al., 2002). eauring o light aborption or other type o radiation (Oliveira et al., 1997; Ryżak et al., 2009) i alo ued or thi purpoe. An intereting variation o the edimentation method i the determination o eight o edimentation particle ettling on a pan immered in upenion a a unction o time (Glińki and Kontankieic 1991). Thi i a time-conuming method; hoever, it i imilar to the pipette method and urthermore it provide the poibility o imultaneou determination o multiple ample in a ingle device. It eem, thereore, that it ould be advantageou to introduce uch a modiication to the edimentation method, hile avoiding, at leat in part, their hortcoming. Thi ne method ould at the ame time give imilar reult ith reduced time outlay. We propoe a method hich hould combine the accuracy o reult obtained uing the pipette method ith the poibility o meauring any number o elected ie raction and a hortened meaurement time in comparion to the SH and P method. To decribe the theoretical bai o the propoed meaurement method it i neceary to recognie phyical orce aecting the loat immered in ater upenion o oil particle ith dierent equivalent diameter. The loat ha a higher denity than the oil upenion and it i hanging on a thin line connected to a high reolution dynamometer. The net orce (G) acting on the loat immered to depth in oil upenion ater time t hen the edimentation tart i equal to: G( ( ρ ( )g, (1) here: G( net orce acting on the loat ubmerged in the oil upenion at a depth ater time t (apparent eight o the loat meaured ith a dynamometer); ma o loat; volume o loat; ρ( denity o oil upenion at the depth ater the time t; g gravitational acceleration. The above equation i approximate due to change in the denity o the upenion at the height o the loat. Soil upenion denity at depth ater edimentation time t can be calculated by dividing the total eight o the olid phae and the ater in the layer ith thickne d by the volume o that layer: ( + d ( d ρ( d ρd ( + d ( d d ( ρ d + d ρ d ( here: d ( ma o the olid phae o oil upenion at the layer having a thickne d at a depth ater time t; d ( ma o ater at the upenion layer having a thickne d at a depth ater time t; d ( volume o ater at the upenion layer having a thickne d at a depth ater time t; ρ denity o ater; ρ denity o olid phae o oil. It i aumed in Eq. (2) that the denity o particle o varying ie i contant, or may by lightly dierent, and it i poible to approximate thi ith the ingle value ρ. The ma o oil olid phae in the upenion layer ith thickne d at depth at time t can be calculated rom the equation:,. (2) d ( d F(., (3) here: total ma o the olid phae o oil upenion (total ma o oil particle); total volume o upenion; F( proportion oil o particle hich are in a unit volume o upenion at a depth ater time t, related to the total eight o oil the particle. So, the denity o upenion at depth ater time t can be decribed a: ρ( ρ 1 ρ + ρ d d F( ρ + ρ (, ) 1 F t. ρ F( + d ρ d F( F( Ater modiication o Eq. (4) to calculate unction F( e obtain: (4)

3 INNOATIE ETHOD FOR DETERINATION OF SOIL GRAIN SIZE COPOSITION 63 ρ( ρ( ρ) F(. (5) ( ρ ρ ) Tranorming Eq. (1) to calculate the denity o oil upenion e obtain: ( g G( ρ (,. g (6) here: g gravitational acceleration. Subtituting Eq. (6) to Eq. (5) e obtain: ρ( ρ( ρ) F( ( ρ ρ ) ( ρ ρ ) ρ ( g G( ) g ρ. The above Eq. (7) deine the relationhip beteen the apparent eight o the loat, ubmerged to depth belo the upenion urace, at time t rom the beginning o edimentation (mixing) and the cumulative raction content o particle that all to depth by time t. Conidering the act that the denity o ater i dependent on temperature, the above equation hould in principle be ritten a: ρ ( g G( ) (7) F ( ρ ( τ ). ( ρ ρ ) (8) g, here: τ temperature o upenion. The unction ρ (τ) in the temperature range C (uch a occur mot requently in edimentation meaurement) can be approximated ith uicient accuracy uing a polynomial o the econd order. Settling velocity o a pherical particle o diameter d and denity ρ in a luid ith denity ρ and dynamic vicoity η can be calculated rom the equilibrium condition o the orce acting on it: 2 d g v ( ρ ρ )., (9) 18η here: ν ettling velocity o a pherical particle o diameter d. The above equation can be applied to pherical particle, in the range o the laminar lo (Reynold number <1), and to the diameter o the container (cylindrical) herein the edimentation occur that i much greater than the diameter o alling particle and there i an abence o interaction beteen particle (Allen, 1997; Smith and ullin, 1991). At the ame time, the diameter o the alling particle mut be greater than the limit at hich the thermal motion keep the particle in upenion. According to Allen et al. (1996), thi particle diameter limit, at hich Bronian motion may move oil particle larger than the ditance o movement caued at the ame time by the orce o gravity, i about 1 mm. The ditance hich particle are moved during edimentation ith velocity v at time t ill be: 2 d g vt ( ρ ρ ) t., (10) 18η here: d diameter o oil particle, η dynamic vicoity o ater. With the little variability o the denity o oil particle belonging to the dierent ie raction and in condition o contant temperature the olloing ubtitution can be aumed: g α cont ( ρ ρ ). 18η (11) In act, α i a unction o temperature, becaue both ρ and η depend on temperature. Baed on the above ubtitution, Eq. (10) can be, thereore, ritten a: αd 2 t. (12) Equation (12) deine the depth to hich, ater time t, a particle ith equivalent diameter d and located cloe to the urace o the upenion at the initial time o edimentation ha allen. Uing a dynamometer to meaure the orce acting on the loat ubmerged in the oil upenion G( (the apparent eight o the loa at deired depth ith the appropriately elected time t 1, t 2,... t n, it i poible, on the bai o Eq. (8), to determine the value o the unction F( or that time. Let u chooe the depth at hich the meaurement o loat apparent eight ill be made and deine thi a p. Selection can be made preciely becaue the dynamometer ork ithout a pring being expoed during the meaurement (the pieoelectric eect i ued). Fall time o oil particle ith diameter d 1 rom the urace o the upenion to depth p can be calculated ater tranormation o Eq. (12): p t1. 2 (13) αd 1 O coure, all particle o ie greater than p and thoe located, at the initial time o edimentation, at any depth belo the upenion urace, all quicker than calculated above. According to the elected diameter d 2, d 3, d n the edimentation time t 2, t 3, t n are calculated uing Eq. (13). It i important that the meauring depth p i ixed and can be reely elected by the experimenter by raiing or loering the dynamometer ith the loat hooked to it on a thread, but not, a i the cae o the hydrometer method, deined by an unknon content o oil particle ith a diameter loer than that meaured in real time.

4 64 J. KASZUBKIEWICZ et al. Factor α in Eq. (12) depend on temperature, and thereore mut be ritten a: α ( τ ) g (14) 18η τ ( ρ ρ( τ )). ( ) The dynamic vicoity o ater η(τ) in the temperature range o C (uch a occur mot requently in meaurement uing the hydrometer method) can be approximated a a unction o temperature, imilar to the ater denity unction, ith the ame acceptable accuracy. To achieve thi, a polynomial o the econd order may be ued. Subtituting Eq. (14) into Eq. (13), e obtain time value or all particle ith required equivalent diameter. Time i calculated according to meaurement o depth and change o temperature. Temperature correction i an important value and it hould not be overlooked. Uing a thin thread ( 0.1 mm), on hich the loat i upended, e avoid the error hich, in the hydrometric method, are aociated ith the diplacement o the hydrometer tem ubmerging at a variable depth, depending on the content o the meaured raction. For the time t 1, t 2,... t n calculated in the above manner e meaure, uing a dynamometer, the value o the unction G( p, t i ), (apparent eight o the loat ubmerged in upenion at the depth p ), and then, uing Eq. (8), e calculate the value o the expreion F( p, t i ). Content o raction ith diameter rom d i to d i+1 hould be then calculated rom the equation: (d i, d i+1 ) F( p, t i ) - F( p, t i+1 ). (15) here: (d i, d i+1 ) raction o oil particle ith the diameter rom d i to d i+1. The value d i and t i are related by Eq. (13). The choice o the depth at hich the meaurement i perormed i determined by practical reaon. I e ant to meaure the raction alling rapidly, it i convenient to chooe a greater depth p to make it poible to loer the loat to the deired depth beore the irt meaurement time (raction ith the larget diameter) and reduce the luid turbulence, hich i a reult o the upenion mixing beore the tart o edimentation. On the other hand, i e ant to meaure the content o mall particle, it i convenient to perorm meaurement at a hallo depth p hich ill give u a igniicant reduction (up to 3 h) o meaurement time or the content o a raction ith diameter le than mm. Due to the non-ero volume o the loat, the method o edimentation p hould be et or the upenion ith the immered loat. Hence, the upenion height o the entire cylinder (H 1 ) ith the ubmerged loat i: + H1 + H0 +, (16) here: H 0 i the height o the upenion in a cylinder ithout a ubmerged loat, S cro ection area o cylinder. So, i e ant to place the centre o buoyancy o the loat at depth p belo the urace, it hould be placed above the bottom o the cylinder at the level: L1 H0 + p, (17) here: L 1 the ditance rom the bottom to the centre o buoyancy o the loat. The above equation indicate that, or a loat ith volume o approximately 40 cm 3 in a tandard cylinder ith a diameter o 61 mm, the correction i about 14 mm. eaurement o upenion denity in thi method a perormed by meauring the apparent eight o the loat attached to a enitive dynamometer and ubmerged in the upenion. The loat a made o gla and had the hape o to cone joined by their bae. The diameter o the bae o the cone a 4 cm and the height a 4.5 cm. The loat a loaded ith lead hot. The eight o the loat in the air a G (0.402 N) and in ater at 23 C it a 5.71 G (0.056 N). The loat a upended to a dynamometer uing a ihing line ith a diameter o 0.06 mm. The required reolution o the dynamometer i 0.01 G, hich i about N. The meaurement range needed depend on the deign o the loat and i approximately 0 to 50 G. The dynamometer ith hitched loat i mounted on a movable arm o mechanied tand and poitioned vertically ith an accuracy o 1 mm. The dynamometer meaure the apparent eight o the loat at interval elected by the oberver. The reult are aved in the memory (maximum 5000 record). The reult are alo tranmitted to an external recording ytem via USB connection. It i important that the poition o the hook o the dynamometer remain ixed during the meaurement o the orce. Thi allo the perormance o meaurement at Fig. 1. Device contruction cheme.

5 INNOATIE ETHOD FOR DETERINATION OF SOIL GRAIN SIZE COPOSITION 65 a c Cumulative raction content (%) 0% ilt, 100% clay b 20% ilt, 80% clay % ilt, 60% clay d 60% ilt, 40% clay e Cumulative raction content (%) % ilt, 20% clay 100% ilt, 0% clay Cumulative raction content (%) Fraction diameter (mm) Fraction diameter (mm) Fig. 2. Comparion o calculated and meaured cumulative raction content curve or mixture o ilt and clay ith the predetermined proportion uing SD. a contant depth choen by the experimenter. The dynamometer e ued a produced by the ark10 company - model An external computer ytem control the movement o the arm o the mechanied tand etting the loat at the repective time and at the deired depth hich are tated by Eq. (12). eaurement o the ditance beteen the lide o the dynamometer and the bae o the intrument i perormed ith an electronic ruler. Baed on thi ditance, the depth o the centre o loat buoyancy i calculated. ovement o the tand arm i carried out at to velocitie. In the irt phae, the arm move at the peed o 30 mm -1, and on reaching a depth cloe to the deired poition the velocity i reduced in order to achieve a higher poitioning accuracy. A enor or meauring the temperature o the oil upenion i alo mounted on the movable arm o the tand. The movement i eected by a DC electric motor and a drive tranmiion compoed o a gearheel and bearing cre. The hole meaurement ytem i mounted on a table, olid bae equipped ith leg ith a vibration damping material on the bae, and a levelling ytem. A chematic diagram o the device contruction i hon in Fig. 1. ATERIALS AND ETHODS In order to tet the propoed method o meaurement the grain ie compoition o artiicially obtained clay and ilt mixture ere aeed. One o the component o thee mixture a kaolinite upplied by the erck company, ith the peciic denity 2.60 g cm -3 and eight lo during heating at 600 C < 15%. The econd component a a ilt material rom the cambic horion o Cambiol located near the village o Stary Walió in the Kłodko alley ith peciic denity o 2.65 g cm -3 and an organic C content belo the detection level or the method o et oxidation ith titration by ammonium erric ulphate. Neither component contained calcium carbonate. Further

6 66 J. KASZUBKIEWICZ et al. on, thee tet ample component ill be conventionally named clay and ilt. Both component ere mixed in the proportion o 20 to 80, 40 to 60, 60 to 40, and 80 to 20%. Particle ie compoition o pure component and mixture ere determined ith the ue o the ieve hydrometer method (SH), ieve pipette method (SP), laer diraction method (LD), and inally by the method decribed above hich or the purpoe o thi tudy i deined a dynamometric (SD ieve dynamometer method). Prior to the analyi o the ilt ample, particle ith diameter > 2 mm ere dry ieved o. Fraction < 2 mm ere ued or urther analyi. Due to it characteritic, the raction > 2 mm a not ieved o or clay. Due to the nature o the tet ample, it a not neceary to remove organic matter or carbonate. Preparation o ample or analyi uing the dynamometric method (SD) a carried out analogouly to SH and SP (ISO 11277: 1998). To increae the eight change o the loat during the meaurement, ample eighing 80 g ere ued. The volume o upenion a cm 3. Ater preparing the tet ample, meaurement o the apparent eight o the loat ere carried out uing a dynamometer ith a reolution o 0.01 G and a meaurement range o 0-50 G. Data ere collected at interval o 5. The loat a initially immered to a depth o 25.5 cm (ditance rom the centre o loat buoyancy to the urace o the upenion) and ater 3600 it a raied to a depth o 23.5 cm, at 4000 to a depth o 19 cm, at 4300 to a depth o 15 cm, at to 9 cm and ater to 5.8 cm. The reult o meaurement (Fig. 2) ere moothed in the range o uing a polynomial o the econd order, and or other time by ragment o linear unction. Beore moothing, the outlier rom the moving average ere rejected, in order to eliminate error reulting rom vibration o meaurement ytem. Total meaurement time taken to determine the content o raction < mm a (4 h 11 m 7 ). The meaurement data comprie 21 ie raction. The analyi a perormed in 3 replication, and the reult ere calculated a the mean o 3 meaurement. Particle ie analyi uing the ieve hydrometer method (SH) a perormed in 3 replication according to ISO 11277: 2005 tandard, and the reult are preented a average o reultant data. In the meaurement carried out ith the ieve pipette method (SP), 12 particle ie raction ere ditinguihed. From thee raction, 6 ere meaured by ieving and alo 6 by pipetting. The equivalent diameter o thoe raction ere in the range o: , , , , , and < mm. The reported reult are the average o three replicate. The analye o the particle ie compoition by laer diraction (LD) ere perormed uing a alvern aterier 2000, equipped ith a Hydro U device. The meaurement ere perormed ater mechanical homogeniation uing 4 min o ultraonic treatment o the upenion. eaurement a conducted or obcuration (turbidity o upenion) at a range beteen 10 and 20%. The target value a obtained ater 4 min o ultraound eect on the upenion. I the obcuration level exceeded the expected value, the ample a diluted by diconnecting the returning tube rom the device, thu not diturbing the ork o the pump, and at the ame time e ytematically upplied ditilled ater (Bieganoki et al., 2010). eaurement ere conducted over a ull range o particle diameter ith a alvern aterier 2000 rom 0.02 to 2000 µm. For meaurement, both He-Ne ga laer ith avelength 633 nm and LED light ith avelength 466 nm ere ued. The olloing optical parameter ere adopted: aborption index 0.1, reractive index or olid particle 1.65 (correponding to the value adopted or aluminium-ilicate); light relectance or ater eaurement ere perormed in 3 replication ithin 5 or a ingle meaurement, ith a 3 interval beteen the repetition. The algorithm or ample ith irregular hape a ued or calculation. For the ample o 100% clay (pure kaolinite), e ued the ulti Narro model and or the remaining ample the General odel (Bieganoki et al., 2015; alvern Intruction anual, 1997). Becaue o the very mall doe o ample ued in the meaurement, pecial attention a paid to ample homogeniation. Thi a achieved by repeatedly mixing and randomiing oil ample beore application to the Hydro U device. RESULTS AND DISCUSSION The reult o meaurement are preented in Fig. 2 a cumulative particle ie ditribution curve. Fig. 2a and 2 ho the curve o 100% clay and 100% ilt ample, hile Fig. 2b, c, d, e ho particle ie curve or mixture ith predetermined proportion (20:80; 40:60; 60:40 and 80:20). In the cae o clay ample, the reult achieved ith the propoed dynamometric method are in cloe agreement ith thoe obtained ith SP and SH, hile LD igniicantly underetimate raction o equivalent diameter - le than mm. A imilar underetimation o the clay raction uing LD i reported or the dierent oil particle by Ryżak and Bieganoki (2010) and Sochan et al. (2012) and or marine ediment and loe (Buurman et al., 2001). Underetimation o raction ith dimenion <0.004 mm i alo noted by Kun et al. (2013) and Beuelinck et al. (1998). Relatively cloe agreement o reult obtained uing both LD and hydrometer-ieve method i reported by Ryżak and Bieganoki (2010).

7 INNOATIE ETHOD FOR DETERINATION OF SOIL GRAIN SIZE COPOSITION 67 Fig. 3. Comparion o choen raction content meaured ith SP and SD.

8 68 J. KASZUBKIEWICZ et al. Cumulative raction content (%) Fraction content (%) Cumulative raction content (%) Fraction content (%) Cumulative raction content (%) Fraction content (%) Cumulative raction content (%) Fraction content (%) Fig. 4. Compariion o calculated and meaured granulometric raction content or chooen oil mixture. Le clear reult ere obtained or the ilt ample. In thi cae, the decribed meaurement method return reult hich are very comparable to the other method (Fig. 2) herein none o the method compared diered rom each other. Only or the raction range beteen and mm did LD give higher reult than the other method. A imilar overetimation or the raction o ine ilt uing LD a oberved by Orechoki et al. (2014). Additionally, Fig. 3 preent a comparion o the content o raction < 0.002; < 0.02 and < 0.05 mm meaured by method SP and SD. A e can ee, the linear regreion determination coeicient, or all examined raction, are above 0.97 and tandard error o etimation i le than 3.37%. The internal tet o accuracy or each method may be the comparion o meaured cumulative particle ie ditribution curve or mixture o to teted ample, ith the calculation being baed on their knon proportion in the mixture and on the particle ie compoition o 100% clay and 100% ilt ample. Thee reult, in the orm o a comparion o calculated and meaured cumulative particle ie ditribution curve or SD, are preented in Fig. 4. It a oberved or SD that the maximum dierence beteen the calculated and meaured particle ie ditribution curve or the tet ample doe not exceed 5.6% (achieved or a mixture containing 40% ilt and 60% clay, or particle ith equivalent diameter o le than mm). For SP, the analogou maximum dierence beteen the calculated and the meaured content o the raction a 4.4% (achieved or a mixture containing 20% ilt and 80% clay, or particle ith equivalent diameter o le than mm). For SH, the maximum dierence beteen the calculated and the meaured content o the raction a 6.0% (achieved or a mixture containing 40% ilt and 60% clay, or particle ith equivalent diameter le than 0.02 mm). For LD, the maximum dierence beteen the calculated and the meaured content o raction a 6.5% (achieved or a mixture containing 40% ilt and 60% clay, or particle ith equivalent diameter le than 0.02 mm). Another accuracy tet or the preented method may be the meaurement o the choen raction carried out at dierent depth and at dierent time. Uing the Eq. (13) one can calculate the meaurement time or dierent depth or a given raction. For example, the raction d < 0.02 mm may be meaured (at 20.6 o C) at a depth o 10 cm ater the time o 274 or at a depth o 20 cm ater the time o 549. The meaurement ere perormed according to the previouly decribed methodology. Table 1 ho the tatitical parameter o the meaurement reult o 5 raction, or previouly decribed clay and ilt mixture. For

9 INNOATIE ETHOD FOR DETERINATION OF SOIL GRAIN SIZE COPOSITION 69 T a b l e 1. Statitical parameter o the meaurement reult Parameter Content o raction (%) ith diameter belo (mm) % ilt, 20% clay in-ax Average SD C (%) % ilt, 40% clay in-ax Average SD C (%) % ilt, 60% clay in-ax Average SD C (%) % ilt, 80% clay in-ax Average SD C (%) SD tandard deviation, C coeicient o variation. each o the teted raction, meaurement ere perormed at depth o 6, 10, 15, 20, 25 and 30 cm ater properly elected time calculated rom the Eq. (13). A method operating properly hould give the ame reult o raction content hen meaured at dierent depth, ater properly elected time reulting rom Eq. (13). Range (max min) preented in Table 1 do not exceed the value o 5.4%. The tandard deviation or the meaurement o one raction at dierent depth do not exceed the value o 2.35%. It can be een that a relatively large diperion o reult occur during meaurement o raction ith the larget diameter. Thi i related ith the hort meaurement time or hallo immerion depth o the loat (about 25 or raction d < 0.05 mm at 6 cm depth o immerion) and peritent upenion turbulence. The exitence o dierence may alo be related to the ettling o edimenting grain on the upper urace o the loat, hich reult in an increae in it eight or larger ettling time (greater depth o meauremen and a decreae in the calculated content o the raction. Hoever, baed on the preented data, it can be etimated that the impact o the depth meaurement on reult value i relatively mall and or the meaurement time larger than ten o econd it i no more than 2%. Thi i alo an indication that the content o raction ith a diameter le than 0.1 mm hould be meaured at the mot acceible depth to extend the time rom the tir to the irt reading and to reduce the impact o turbulence in the upenion. Hoever, or raction maller than 0.02 mm, it i appropriate to raie the loat a cloe to the urace a poible to horten the analyi time. Obtaining correct reult ith the ue o the preented meaurement method require the maintenance o previouly indicated condition, and additional dependencie need to be conidered. The denity o ater (eentially a mixture o ater odium hexametaphophate and odium carbonate) and the value o coeicient α and η ued in Eq (9) (14) depend on temperature.

10 70 J. KASZUBKIEWICZ et al. A a reult o the conducted tet calculation or the temperature range o o C, it a ound that the obtained raction content (ie to 0.05 mm) changed by 0.4 to 0.5% ith a temperature change o 1 C. Knoledge o temperature in the coure o the reearch i thereore important, but at the ame time a light error in it aement (at C) doe not caue igniicant error in the calculation o raction content. The impact o error in meauring the eight o the loat a alo analyed. A previouly mentioned, the reolution o the dynamometer a 0.01 G. Dynamometer ith a higher reolution hich ould imultaneouly have a capacity o at leat 50 G are not yet commercially available. For a 80 g ample, the change o eight o loat rom the tate that hypothetically all oil particle are upended in ater to complete edimentation (pure ater) i 1.89 G. Thu, or 1% o the particle the change in the eight o the loat i G. Uing reult moothing and interpolation, e can read the eight o the loat ith a reolution o the order o G, hich mean that or the 80 g ample e are able to read the content o raction ith an accuracy o about 0.2%. Obviouly, ample eight reduction reult in increaed error in reading the content o the raction. For a 60 g ample, a loat eight change o G occur in a 1% raction and it i poible to read the content o the raction ith an accuracy o about 0.3%. In turn, or a 40 g ample, a loat eight change o G occur in a 1% raction and it i poible to read the content o the raction ith an accuracy o about 0.4%. At the ame time, the author are aare that increaing ample ma may increae the interaction beteen the edimenting particle (Allen, 1997). Cloer examination o thi iue ill require appropriate reearch uing ample ith dierent eight. In principle, one could improve the meaurement reolution uing a loat o a larger volume. Thi ould imply an increae in total loat eight (a loat mut have a denity greater than the denity o ater) but, a mentioned, available preciion dynamometer have a maximum capacity o 50 G. Although an increae in the volume o the loat i impoible ithout the ue o a dynamometer ith high reolution and a greater capacity, optimiation o it hape i needed. The hortet poible meaurement depth o edimentation i equal to the ditance rom the tip o the loat to it centre o buoyancy. In the currently ued loat, thi ditance i 58 mm, hile hape change to a helical cone hould enable hortening it to about 40 mm. Thi mean a hortened edimentation time or raction < mm (at 22.5 C) rom to The cope o application o the propoed method or clay raction i, a in all edimentation method, limited by the inluence o Bronian motion. According to Allen et al. (1996), the loer limit o the ie o meaured particle i thu equal to mm. At the other end o the meauring cale, ie or a grain ie cloe to 0.1 mm, the problem i the hort time beteen the end o upenion tirring and the irt reading. Thereore, a uitable peed o loat loering and method o data moothing i needed. It ha been ound that or a time longer than 100 it i uicient to mooth the meaurement data ith ection o a linear unction, but or a time le than 100 a moothing polynomial o the econd order i needed. The method ill not encounter limitation hen analying bimodal oil, hich i not evident in LD method (Blott and Pye, 2006). In contrat to LD, thi method doe not alo require any anticipatory aumption about the hape o grain ie ditribution unction. A eparate problem i the impact o deviation rom the pherical particle hape o oil particle on the meaurement reult (Ehel et al., 2004). It i poible to replace Eq. (6) ith another one uitable or the hape o edimenting particle (Dietrich, 1982); hoever, thi require inormation about their hape. A imilar problem applie to all method o grain ie compoition analyi (Polakoki et al., 2014). The author believe that the optimiation o the loat hape, control o upenion temperature and accurate meaurement o the loat immerion depth ill reduce meaurement error and allo to obtain reproducible reult at the level o 1%. CONCLUSIONS Compared to the previouly ued edimentation method, the developed method ha everal igniicant advantage. 1. By meauring the denity o the upenion at the deired depth choen by reearcher, the method enable hortening o the depth o edimentation and thu igniicantly horten the time o analyi up to 3 h. 2. The ue o a dynamometer ith digital recording allo the proceing o the meaured value o denity in digital ormat and intant calculation o grain ie compoition. Poible error o obervation are, thereore, eliminated. The coure o the meaurement proce i controlled by computer otare. 3. Ater the tart o edimentation (mixing o upenion), meaurement are perormed automatically, alloing ta to ue the time or other activitie uch a preparation o urther ample. Proper management o time and changing cylinder ith upenion allo meaurement ith one device in everal cylinder imultaneouly. 4. A indicated by perormed tet meaurement, the reult obtained ith the propoed method are reproducible and exhibit cloe agreement ith thoe obtained ith the ue o the pipette method hich i regarded a the reerence method. In comparion to laer diraction method,

11 INNOATIE ETHOD FOR DETERINATION OF SOIL GRAIN SIZE COPOSITION 71 the propoed olution i cheaper, and the reult obtained are more cloely compatible ith other edimentation method. 5. The phyical phenomenon ued i the ame a that hich deine the character and propertie o naturally occurring ediment. Conlict o interet: The Author declare no conlict o interet. REFERENCES Agraal Y.C., ccave I.N., and Riley J.B., Laer diraction ie analyi. In: Principle, ethod and Application o Particle Sie Analyi (Ed. J.P.. Syvitki). Cambridge Univerity Pre, UK. Allen T., Particle ie meaurement. ol. 1, Chapman and Hall, London, UK. Allen T., Davie R., and Scarlett B., Particle ie meaurement. ol. 2, Chapman and Hall, London, UK. Bah A.R., Kravchuk O., and Kirchho G., Fitting perormance o particle-ie ditribution model on data derived by conventional and laer diraction technique. Soil Sci. Soc. America J., 73, Beuenlick L., Gover G., Poeen J., Degraer G., and Froyen L., Grain ie analyi by laer diractometry: comparion ith ieve-pipette method. Catena, 32, Bieganoki A., alý S., Frąc., Tu I.H., áňa., Breińka., Siebielec G., Lipiec J., and Šarapatka B., Particle ie ditribution meaured by laer diraction method. In: Laboratory manual. Central Intitute or Superviing and Teting in Agriculture, Brno, Cech Republic. Bieganoki A., Ryżak., and Witkoka-Walcak B., Determination o oil aggregate diintegration dynamic uing laer diraction. Clay ineral, 45, Bieganoki A. and Walcak R.T., Speciicity o agrophyical meaurement. Problem o tandardiation and validation o method. In: Baic problem o agrophyic (Ed D. atyka-saryńka, R,T. Walcak). Intitute o Agrophyic PAS, Lublin, Poland. Blott S.J. and Pye K., Particle ie ditribution analyi o and-ied particle by laer diraction: an experimental invetigation o intrument enitivity and the eect o particle hape. Sedimentology, 53(3), Buurman P., Pape Th., Reijneveld J.A., De Jong F., and an Gelder E., Laer-diraction and pipette-method grain iing o Dutch ediment: correlation or ine raction o marine, luvial, and loe ample. Netherland J. Geocience, 80, Di Steano C., Ferro., and irabile S., Comparion beteen grain-ie analye uing laer diraction and edimentation method. Bioy. Eng., 106, Dietrich W., Settling velocity o natural particle. Water Re. Re., 18(6), Ehel G., Levy G.J., ingelgrin U., and Singer.J., Critical evaluation o the ue o laer diraction or particle-ie ditribution analyi. Soil Sci. Soc. Am. J., 68, Gee G.W. and Bauder J.W., Particle-ie analyi by hydrometer: A impliied method or routine textural analyi and a enitivity tet o meaurement parameter. Soil Sci. Soc. Am. J., 43, Glińki J. and Kontankieic K., ethod and apparatu or agrophyical reearch (in Polih). Problemy Agroiyki 64, Oolineum Wrocła, Polka. ISO 11277:1998. Soil quality - Determination o particle ie ditribution in mineral oil material - ethod by ieving and edimentation. Komornicki T. and Jakubiec J., Remark on the areometric method or oil mechanical analyi a modiied by. Próyńki. Part 5: A comparion o everal granulometric method. Acta Agraria et Silvetria. Serie Agraria, 1, Konert. and andenberghe J., Comparion o laer grain ie analyi ith pipette and ieve analyi: a olution or the underetimation o the clay raction. Sedimentology, 44, Kovác B., Cinkota I., Tolner L., and Cinkota G., The determination o particle ie ditribution (PSD) o clayey and ilty ormation uing the hydrotatic method. Acta mineralogica-petrographica, 45, Kovác B., Cinkota I., Tolner L., and Cinkota G., Fit method or calculating oil particle ie ditribution rom particle denity and ettling time data. Agrokémia é Talajtan, Kun A., Katona O., Sipo G., and Barta K., Comparion o pipette and laer diraction method in determining the granulometric content o luvial ediment ample. J. Environ. Geography, 6, Loth E., Drag o non-pherical olid particle o regular and irregular hape. Poder Technology, 182(3), alverm aterier 2000 Intruction anual, Neme A., Cinkota I., Cinkota G., Tolner L., and Kovác B., Outline o an automated ytem or quay-continou meaurement o particle ie ditribution. Agrokémia é Talajtan, 51, Oden S., Eine neue ethode ur mechanichen Bodenanalye. Int. itt. Bodenanal., 5, Oliveira J..C., a C..P., Reichardt K., and Sartendruber D., Improved oil particle-ie analyi by gamma-ray attenuation. Soil Sci. Soc. Am. J., 61, Orechoki., Smólcyńki S., Długo J., and Poźniak P., eaurement o texture o oil ormed rom glaciolimnic ediment by areometric method, pipette method and laer diraction method. Soil Sci. Annual, 65(2), Polakoki C., Sochan A., Bieganoki A., Ryżak., Földényi R., and Tóth J., Inluence o the and particle hape on particle ie ditribution meaured by laer diraction method. Int. Agrophy., 28, Ryżak., Bartmińki P., and Bieganoki A., ethod or determination o particle ie ditribution o mineral oil (in Polih). Acta Agrophyica, 175, Ryżak. and Bieganoki A., Determination o particle ie ditribution o oil uing laer diraction comparion ith areometric method. Int. Agrophy., 24(2),

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