1、Designation: D 1997 91 (Reapproved 2008)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:2D 2974 Test Methods for Moisture, Ash, and Organic Mat-ter of Peat and Other Organic SoilsD 4427 Classification of Peat Samples by Laboratory Test-ingE11 Specification
6、for Wire Cloth and Sieves for TestingPurposes3. 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 Method34.1 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 E11) by a
8、pplica-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 stan
9、dardize 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 the
10、 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, activate
11、d 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 E11).6.2 Drying Oven, capable of being set at 105C 6 5C.6.3 Balance, capable of measuring at least to the neare
12、stmilligram.6.4 Standard Laboratory Stirrer, capable of being set to 240r/min.6.5 Beaker, 1000-mL capacity.6.6 Large Funnel.6.7 Hydrochloric Acid (HCl) Tank or Pan.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.22
13、 on Soil as a Mediumfor Plant Growth.Current edition approved Jan. 1, 2008. Published February 2008. Originallyapproved in 1991. Last previous edition approved in 2001 as D 1997 91 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service
14、astm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3This test method is a modified version of one described in: Riley, J. L.,“Laboratory Methods for Testing Peat,” Ontario Peatland Inventory Project, OntarioGeological Survey
15、 Open File Report 5572, 1986, p. 2122.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.8 Filter Paper.7. Reagents7.1 Sodium Hexametaphosphate, 5 % solution.7.2 Hydrochloric Acid (HCl), 2 % solution.8. Procedure8.1 Select a represent
16、ative 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 mL of 5 % sodium hexametaphosphatesolution (dispersing agent
17、). 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) stainless steel sieve (orpiece of sieve screen) held over a sin
18、k 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 the sieve. Wash until water passing through thescreen is clea
19、r.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). Dispose waste solution containing HCl safely.8.9 Remove from the
20、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#4 or equivalent). Wash all of the fibers off the screen into t
21、hefunnel 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 achieved (at least 24 h).8.12 Record the mass of the dried sam
22、ple 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. Rewashthe residue after ashing, and record the mass. Then subtract
23、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 asa percent of the oven dry mass.9.2 Fiber content, % = Mf/Ms
24、3 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 yet beendetermined. Data are being sought that will be suitab
25、le 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. Users of this standard are expressly advised that determinat
26、ion 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 every five years andif not revised, either reapproved or withd
27、rawn. 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 technical committee, which you may attend. If you feel that your
28、 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 1997 91 (2008)2
