1、Designation: D1987 18Standard Test Method forBiological Clogging of Geotextile or Soil/Geotextile Filters1This standard is issued under the fixed designation D1987; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used to determine the potential for,and relative degree of, biological growth which can accumulateon geo
3、textile or geotextile/soil filters.1.2 This test method uses the measurement of flow ratesover an extended period of time to determine the amount ofclogging.1.3 This test method can be adapted for nonsaturated as wellas saturated conditions.1.4 This test method can use constant head or falling headm
4、easurement techniques.1.5 This test method can also be used to give an indicationas to the possibility of backflushing, biocide treatment, or both,for remediation purposes if biological clogging does occur.1.6 The values in SI units are to be regarded as the standard.The values provided in inch-poun
5、d units are for informationonly.1.7 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, health, and environmental practices and deter-mine the applicability of reg
6、ulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade
7、Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products (RECPs) for TestingD4439 Termino
8、logy for GeosyntheticsD4491 Test Methods for Water Permeability of Geotextilesby PermittivityD5101 Test Method for Measuring the Filtration Compat-ibility of Soil-Geotextile SystemsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG22 Practice for Determ
9、ining Resistance of Plastics toBacteria (Withdrawn 2002)33. Terminology3.1 Definitions:3.1.1 aerobic, na condition in which a measurable volumeof air is present in the incubation chamber or system.3.1.1.1 DiscussionIn geotextiles, this condition can poten-tially contribute to the growth of microorga
10、nisms.3.1.2 anaerobic, na condition in which no measurablevolume of air is present in the incubation chamber or system.3.1.2.1 DiscussionIn geotextiles, this condition cannotcontribute to the growth of microorganisms.3.1.3 back flushing, na process by which liquid is forcedin the reverse direction t
11、o the flow direction.3.1.3.1 DiscussionIn other drainage application areas,this process is commonly used to free clogged drainagesystems of materials that impede the intended direction of flow.3.1.4 biocide, na chemical used to kill bacteria and othermicroorganisms.3.1.5 geotextile, na permeable geo
12、synthetic comprisedsolely of textiles.3.1.6 permeability, nthe rate of flow of a liquid under adifferential pressure through a material.3.1.6.1 DiscussionIn geotextiles, permeability refers tohydraulic conductivity.3.1.7 permittivity, ()(t1), nof geotextiles, the volumetricflow rate of water per uni
13、t, in a cross-sectional area head underlaminar flow conditions.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved Feb. 1, 2018. Published February 2018. Originally
14、approved in 1991. Last previous edition approved in 2016 as D1987 07 (2016).DOI: 10.1520/D1987-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Docu
15、ment Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with inter
16、nationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2 For definitions of other terms used in this
17、test method,refer to Terminologies D123 and D4439.4. Summary of Test Method4.1 A geotextile filter specimen or geotextile/soil filtercomposite specimen is positioned in a flow column so that adesignated liquid flows through it under either constant orfalling head conditions.4.1.1 The designated liqu
18、id might contain microorganismsfrom which biological growth can occur.4.2 Flow rate is measured over time, converted to eitherpermittivity or permeability, and reported accordingly.4.2.1 Between readings, the test specimen can be allowed tobe in either nonsaturated or saturated conditions.4.2.2 Back
19、 flushing can be introduced from the directionopposite to the intended flow direction and evaluated accord-ingly.4.2.3 Biocide can be introduced with the back flushingliquid, or introduced within the test specimen, and evaluatedaccordingly.5. Significance and Use5.1 This test method is performance o
20、riented for determin-ing if, and to what degree, different liquids create biologicalactivity on geotextile filters thereby reducing their flow capa-bility. The use of the method is primarily oriented towardlandfill leachates but can be performed with any liquid comingfrom a particular site or synthe
21、sized from a predeterminedmixture of biological microorganisms.5.2 The test can be used to compare the flow capability ofdifferent types of geotextiles or soil/geotextile combinations.5.3 This test will usually take considerable time, forexample, up to 1000 h, for the biological activity to initiate
22、,grow, and reach an equilibrium condition. The curves resultingfrom the test are intended to indicate the in situ behavior of ageotextile or soil/geotextile filter.5.4 The test specimen can be incubated under nonsaturateddrained conditions between readings, or kept saturated at alltimes. The first c
23、ase allows for air penetration into the flowcolumn and thus aerobic conditions. The second case can resultin the absence of air, thus it may simulate anaerobic conditions.5.5 The flow rate can be determined using either a constanthead test procedure or on the basis of a falling head testprocedure. I
24、n either case, the flow column containing thegeotextile or soil/geotextile is the same; only the head controldevices change.NOTE 1It has been found that once biological clogging initiates,constant head tests often pass inadequate quantities of liquid to accuratelymeasure. It thus becomes necessary t
25、o use falling head tests, which can bemeasured on the basis of time of movement of a relatively small quantityof liquid between two designated points on a clear plastic standpipe.5.6 If the establishment of an unacceptably high degree ofclogging is seen in the flow rate curves, the device allows for
26、backflushing with water or with water containing a biocide.5.7 The resulting flow rate curves are intended for use in thedesign of full scale geotextile or soil/geotextile filtrationsystems and possible remediation schemes in the case oflandfill lechate collection and removal systems.6. Apparatus6.1
27、 The Flow Column and Specimen Mount consists of a100-mm (4.0-in.) inside diameter containment ring for place-ment of the geotextile specimen along with upper and lowerflow tubes to allow for uniform flow trajectories (see Fig. 1).The flow tubes are each sealed with end caps which have entryand exit
28、tubing connections (see Fig. 1). The upper tube can bemade sufficiently long so as to provide for a soil column to beplaced above the geotextile. When this type of combinedsoil/geotextile cross section is used, however, it is difficult todistinguish which material is clogging, for example, the soil
29、orthe geotextile. It does, however, simulate many existing filtra-tion systems. In such cases, a separate test setup with thegeotextile by itself will be required as a control test, and thedifference in behavior between the two tests will give anindication as to the contribution of soil clogging to
30、the flowreduction.NOTE 2If piezoemetric heads in the material (soil or solid waste)located above the filter are desired, the upper flow column of thepermeameter can be modified to accommodate such measurements.Recommended are ports immediately above the filter (as close to it aspossible), and at14,1
31、2,34 and above the soil or solid waste in question.Duplicate ports on each side of the permeameter at the above elevationsare considered good practice in measurements of this type. Otherconfigurations are at the option of the parties involved.The ports are connected by flexible tubing to a manometer
32、 board forreadings in a manner that is typical for measurements of this type. See TestMethod D5101, the Gradient Ratio test, for additional details.6.2 Hydraulic Head Control Devices are required at both theinlet and outlet ends of the flow column. Fig. 2 shows thecomplete setup based on constant hy
33、draulic head monitoringwhere concentric plastic cylinders are used with the innerFIG. 1 Flow Column to Contain Geotextile Test SpecimenD1987 182cylinders being at the elevation from which head is measured.The elevation difference between the inner cylinder at the inletend and the inner cylinder at t
34、he outlet end is the total headacross the geotextile test specimen (or soil/geotextile testspecimen in the case of a combined test column). Note that theelevation of the outlet must be above the elevation of thegeotextile.6.3 A Hydraulic Head Standpipe above the flow column isrequired for falling hy
35、draulic head monitoring. Fig. 3 showsthis type of test configuration in which a clear, plastic standpipeis placed above the flow column. Liquid movement is moni-tored for the time of flight between two marks on the standpipe.Note that the elevation of the outlet must be above theelevation of the geo
36、textile.6.4 The Overall Test System dimensions are sufficientlysmall so that either of the above-mentioned units can be usedat a field site, if desirable. They can either be kept stationary inthe laboratory or in the field, or they can be transported fromthe laboratory to the field site when require
37、d.6.5 The Permeating Liquid is generally site specific andoften comprises landfill leachate. Other liquids for whichbiological clogging is of concern can also be evaluated. Theliquid can be synthesized on an as-required basis.NOTE 3A synthesized liquid which has been used in determining theresistanc
38、e of plastics to bacteria is Pseudomonas aeruginosaATCC 133884or MYCO B1468.5Specific details must be agreed upon by the partiesinvolved. See also Practice G22.7. Sampling7.1 Lot SampleDivide the product into lots and take thelot sample as directed in Practice D4354.7.2 Laboratory SampleFor the labo
39、ratory sample, take aswatch extending the full width of the geotextile of sufficientlength along the selvage from each sample roll so that therequirements of the following section can be met. Take asample that will exclude material from the outer wrap and innerwrap around the core unless the sample
40、is taken at theproduction site, then inner and outer wrap material may beused.7.3 Test SpecimensFrom the laboratory sample, select thenumber of specimens as per the number of flow columns to beevaluated. Space the specimens along a diagonal on the unit ofthe laboratory sample. Take no specimens near
41、er the selvage oredge of the laboratory sample than 10 % of the width of thelaboratory sample. The minimum specimen diameter should be100 mm (4.0 in.) so that full fixity can be achieved around theinside of the flow column.8. Conditioning8.1 There is no conditioning of the geotextile test specimen,p
42、er se, since this test method is a hydraulic one and theconditions of the permeating fluid will be the controlling factor.See also Practice D1776.8.2 The relative humidity should be 100 % except duringtimes of air drying between nonsaturated test readings. Forsaturated conditions, the relative humid
43、ity should always be100 %.8.3 The temperature of the test over its entire duration isimportant. It is desirable to track temperature continuously. Ifnot possible, frequent readings at regular intervals are required.9. Procedure9.1 Procedure A Constant Head Test:9.1.1 Select and properly prepare the
44、geotextile test speci-men. Trim the specimen to the exact and full diameter of theinside of the flow column.4Available from American Type Culture Collection, 12301 Parklawn Drive,Rockville, MD 20852.5Available from Mycological Services, P.O. Box 126, Amherst, MA 01002.FIG. 2 Flow Column with Inlet a
45、nd Outlet Hydraulic Head ControlDevices for Constant Head TestFIG. 3 Flow Column with Standpipe for Variable (Falling) HeadTestD1987 1839.1.2 Fix the geotextile test specimen to the inside of thecontainment ring. If a water-insoluble glue is used, be sure thatany excess does not extend into the flow
46、 area of the geotextile.9.1.3 Caulk the upper surface of the geotextile to the insideof the containment ring using a silicon-based caulk and allowit to completely cure. The caulk must be carefully placed so asnot to restrict flow through the geotextile.9.1.4 Insert the upper and lower tubes into the
47、 containmentring and create a seal. If polyvinyl chloride (PVC) tubing andfittings are being used, first a cleaner and then a solvent wipeis used to make the bond.9.1.5 If a screen or gravel of approximately 50 mm (2 in.)size is necessary to support the geotextile, it must be placedwith the device i
48、n an inverted position.9.1.6 Place the lower end cap on the device and make it seal.9.1.7 If soil is to be placed over the geotextile, place it atthis time. Place the soil at its targeted moisture content anddensity, taking care not to dislodge or damage the geotextilebeneath.9.1.8 Place the upper e
49、nd cap on the device and make apermanent seal.9.1.9 Connect flexible plastic tubing from the flow columnstop and bottom to the head control devices. At this point thesystem should appear as shown in the photograph of Fig. 2.9.1.10 Adjust the total head lost to 50 mm (2.0 in.) andinitiate flow via the introduction of the permeating fluid to thesystem. When using leachate, proper safety and health precau-tions must be maintained depending upon the nature of theleachate itself.NOTE 4It is suggested to use 50 mm (2 in.) total head difference sincethis is the
