1、Designation: D 1997 91 (Reapproved 2001)Standard Test Method forLaboratory Determination of the Fiber Content of PeatSamples by Dry Mass1This standard is issued under the fixed designation D 1997; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the laboratory determination ofthe fiber content of samples of peat
3、 (as defined in ClassificationD 4427) by dry mass. It also may be used for non-peat organicsoil materials.1.2 Because this test method is simple and requires nosophisticated equipment to perform, it is especially recom-mended for routine reconnaissance work, where large numbersof samples need to be
4、tested and mineral contents are low.1.3 The values stated in SI units are to be regarded as thestandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and
5、health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 2974 Test Methods for Moisture, Ash, and Organic Mat-ter of Peat and Other Organic Soils2D 4427 Classification of Peat Samples by Laboratory Test-ing2E 11 Specificatio
6、n for Wire-Cloth Sieves for Testing Pur-poses33. Terminology3.1 Definition of Term Specific to This Standard:3.1.1 fibera fragment or piece of plant tissue that retainsa recognizable cellular structure and is large enough to beretained on a 100-mesh sieve (openings 150 m). Plantmaterials larger than
7、 20 mm in smallest dimension are notconsidered fibers.4. Summary of Test Method44.1 A known mass of undisturbed, undried peat is soaked ina dispersing agent (5 % sodium hexametaphosphate) for ap-proximately 15 h. The material is then washed through a100-mesh (150 m) sieve (see Specification E 11) by
8、 applica-tion of a gentle flow of tap water. The fibrous material left onthe sieve is oven-dried (at 105C) until a constant mass isachieved. The mass of fiber is expressed as a percentage of theoven-dried mass of the original sample.5. Significance and Use5.1 The purpose of this test method is to st
9、andardize theprocedure for determining fiber content of peat samples by drymass.5.2 A standard test method for determining the quantity offibers in a peat sample is necessary not only for classifyingsamples (as in Classification D 4427), but is also a significantparameter in predicting or defining t
10、he many end uses of peat.In this regard, fiber content has been related to agricultural andhorticultural end uses (such as mulching, soil enrichment, etc.),geotechnical measurements (such as strength, compressibility,permeability, etc.), industrial chemical uses (such as produc-tion of waxes, activa
11、ted carbon, medicinals, etc.), and evenenergy uses (such as direct combustion, methanol production,gas yields, etc.).6. Apparatus6.1 Sieve, standard ASTM 100 mesh (150 m) (see Speci-fication E 11).6.2 Drying Oven, capable of being set at 105C 6 5C.6.3 Balance, capable of measuring at least to the ne
12、arestmilligram.6.4 Standard Laboratory Stirrer, capable of being set to 240r/min.6.5 Beaker, 1000-mL capacity.6.6 Large Funnel.1This test method is under the jurisdiction of ASTM Committee D 18 on Soiland Rock and is the direct responsibility of Subcommittee D18.22 on Soil as aMedium for Plant Growt
13、h.Current edition approved April 15, 1991. Published June 1991.2Annual Book of ASTM Standards, Vol 04.08.3Annual Book of ASTM Standards, Vol 14.02.4This test method is a modified version of one described in: Riley, J. L.,“Laboratory Methods for Testing Peat,” Ontario Peatland Inventory Project, Onta
14、rioGeological Survey Open File Report 5572, 1986, p. 2122.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.7 Hydrochloric Acid (HCl) Tank or Pan.6.8 Filter Paper.7. Reagents7.1 Sodium Hexametaphosphate, 5 % solution.7.2 Hydrochloric
15、 Acid (HCl), 2 % solution.8. Procedure8.1 Select a representative sample of undried peat anddetermine its water content in accordance with Test MethodsD 2974.8.2 Separate out a specimen of approximately 100 g andrecord its mass, M.8.3 Place this specimen in a 1000 mL beaker and addapproximately 500
16、mL of 5 % sodium hexametaphosphatesolution (dispersing agent). Stir thoroughly and let stand for atleast 15 h.8.4 After the specimen has stood 15 h, stir it thoroughlyusing a laboratory stirrer at 240 r/min for 10 min. Avoid higherspeeds or longer stirring periods.8.5 Pour over a 100 mesh (150 m) st
17、ainless steel sieve (orpiece of sieve screen) held over a sink or other suitablecontainer for disposal.8.6 Wash to peat on the screen using a rubber hose attachedto a water faucet. Avoid a jet of high pressure water that wouldtend to force the fiber through the screen or splash it out overthe top of
18、 the sieve. Wash until water passing through thescreen is clear.8.7 Place the sieve with the peat fiber into a shallow tankcontaining a 2 % solution of HCl for at least 10 min (todissolve any carbonates that may be present).8.8 Wash again with water to remove residual HCl (approxi-mately 5 min). Dis
19、pose waste solution containing HCl safely.8.9 Remove from the screen any large mineral grains andalso any large (greater than 20 mm pieces of plant materialsuch as roots or wood).8.10 Invert screen over a large funnel containing a piece offilter paper of known mass to the nearest milligram (Whatman#
20、4 or equivalent). Wash all of the fibers off the screen into thefunnel from the back of the screen to dislodge any fibers stuckto the screen.8.11 After the water has drained through the funnel, removethe filter paper containing the fibers and dry in a drying ovenset at 105C until a constant mass is
21、achieved (at least 24 h).8.12 Record the mass of the dried sample to the nearestmilligram. This mass minus the mass of the filter paper is themass of the fibers. Record this mass as Mf.8.13 It may be necessary to ash the sample in accord withTest Methods D 2974 to separate the mineral content. Rewas
22、hthe residue after ashing, and record the mass. Then subtract thismass from Mfin order to obtain a true mass of fibers.9. Calculation9.1 The initial mass of dry soils Ms= (100 w)M if watercontent is expressed as a percent of the as-received mass ofMs=M/(w+100) 3 100 if the water content is expressed
23、 asa percent of the oven dry mass.9.2 Fiber content, % = Mf/Ms3 100where:Mf= dry mass of fibers (from 7.12 or 7.13),Ms= initial dry mass of soil,M = initial total mass of sample, andw = %water as determined in Test Methods D 2974.10. Precision and Bias10.1 The precision of these test methods has not
24、 yet beendetermined. Data are being sought that will be suitable for usein developing precision statements.11. Keywords11.1 deposit thickness; peat; probingASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard
25、. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed
26、every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible te
27、chnical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 19972
