ASTM D1987-2007(2012) Standard Test Method for Biological Clogging of Geotextile or Soil Geotextile Filters《土工织物或土壤 土工织物倒滤层的生物堵塞的标准试验方法》.pdf

1、Designation: D1987 07 (Reapproved 2012)Standard 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,

2、the year of last revision. 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 ca

3、n accumulateon geotextile 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 hea

4、d or falling headmeasurement techniques.1.5 This test method can also be used to give an indicationas to the possibility of backflushing and/or biocide treatmentfor remediation purposes if biological clogging does occur.1.6 The values in SI units are to be regarded as the standard.The values provide

5、d in inch-pound 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 and health practices and determine the applica-bility of regul

6、atory limitations prior to use.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 Terminology for GeosyntheticsD449

7、1 Test Methods for Water Permeability of Geotextilesby PermittivityD5101 Test Method for Measuring the Filtration Compat-ibility of Soil-Geotextile SystemsG22 Practice for Determining Resistance of Plastics toBacteria (Withdrawn 2002)3E691 Practice for Conducting an Interlaboratory Study toDetermine

8、 the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 geotextile, na permeable geosynthetic comprisedsolely of textiles.3.1.2 permeability, nthe rate of flow of a liquid under adifferential pressure through a material.3.1.2.1 DiscussionIn geotextiles, permeability refers tohydraulic con

9、ductivity.3.1.3 permittivity, ()(t1), nof geotextiles, the volumetricflow rate of water per unit, in a cross sectional area head underlaminar flow conditions.3.1.4 aerobic, na condition in which a measurable volumeof air is present in the incubation chamber or system.3.1.4.1 DiscussionIn geotextiles

10、, this condition can poten-tially contribute to the growth of micro-organisms.3.1.5 anaerobic, na condition in which no measurablevolume of air is present in the incubation chamber or system.3.1.5.1 DiscussionIn geotextiles, this condition cannotcontribute to the growth of microorganisms.3.1.6 back

11、flushing, na process by which liquid is forcedin the reverse direction to the flow direction.3.1.6.1 DiscussionIn other drainage application areas,this process is commonly used to free clogged drainagesystems of materials that impede the intended direction of flow.3.1.7 biocide, na chemical used to

12、kill bacteria and othermicroorganisms.3.2 For definitions of other terms used in this test method,refer to Terminology 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 a1This test method is und

13、er the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved July 1, 2012. Published July 2012. Originally approvedin 1991. Last previous edition approved in 2007 as D1987 07. DOI: 10.1520/D1987-07

14、R12.2For 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 Document Summary page onthe ASTM website.3The last approved version of this historical standard is

15、 referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1designated liquid flows through it under either constant orfalling head conditions.4.1.1 The designated liquid might contain micro-organismsfrom which biologic

16、al growth can occur.4.2 Flow rate is measured over time, converted to eitherpermittivity or permeability, and reported according.4.2.1 Between readings, the test specimen can be allowed tobe in either nonsaturated or saturated conditions.4.2.2 Back flushing can be introduced from the directionopposi

17、te 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 oriented for determin-ing if, and to what degree, dif

18、ferent 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 synthesized from a predeterminedmixture of biological micr

19、oorganisms.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,grow, and reach an equilibrium condition. The curve

20、s 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 non-saturateddrained conditions between readings, or kept saturated at alltimes. The first case allows for air penetration into the flowcolumn

21、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. In either case the flow column containing thegeotext

22、ile 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 to use falling head tests which can bemeasured on the

23、 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 forbackflushing with water or with water containing a bi

24、ocide.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 The flow column and specimen mount, consists of a 10

25、0mm (4.0 in.) inside diameter containment ring for placement ofthe geotextile specimen along with upper and lower flow tubesto allow for uniform flow trajectories (see Fig. 1). The flowtubes are each sealed with end caps which have entry and exittubing connections (see Fig. 1). The upper tube can be

26、 madesufficiently long so as to provide for a soil column to be placedabove the geotextile. When this type of combined soil/geotextile cross section is used, however, it is difficult todistinguish which material is clogging, for example, the soil orthe geotextile. It does however simulate many exist

27、ing 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 the flowreduction.NOTE 2If piezoemetric heads in the mat

28、erial (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 at14,12,34 and above the soil or solid waste in question.Dupli

29、cate 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 board forreadings in a manner that is typical for measu

30、rements 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 hydraulic head monitoringwhere concentric plastic cylinde

31、rs are used with the innercylinders being at the elevation from which head is measured.The elevation difference between the inner cylinder at the inletend and the inner cylinder at the outlet end is the total headacross the geotextile test specimen (or soil/geotextile testspecimen in the case of a c

32、ombined test column). Note that theelevation of the outlet must be above the elevation of thegeotextile.FIG. 1 Flow Column to Contain Geotextile Test SpecimenD1987 07 (2012)26.3 A hydraulic head standpipe , above the flow column isrequired for falling hydraulic head monitoring. Fig. 3 showsthis type

33、 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 geotextile.6.4 The overall test system, dimensions

34、 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 required.6.5 The permeating liquid, is generally site

35、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 theresistance of plastics to bacteria is Pseudomonas aerug

36、inosaATCC 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 laboratory sample, take aswatch extending the full

37、 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 is taken at theproduction site, then inner and

38、 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 nearer the selvage oredge of the laboratory sample

39、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,per se, since this test method is a hydraulic on

40、e 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 humidity should always be100 %.8.3 The temperature of

41、 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 AConstant Head Test:9.1.1 Select and properly prepare the geotextile test speci-men. Trim the specimen to t

42、he exact and full diameter of theinside of the flow column.9.1.2 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 area of the geotextile.9.1.3 Caulk the upper surface of the geotextile to the

43、 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 containmentring and create a seal. If polyvinyl chloride (PVC) tubing andfitt

44、ings are being used, first a cleaner and then a solvent wipeis used to make the bond.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 and Outlet Hydraulic Hea

45、d ControlDevices for Constant Head TestFIG. 3 Flow Column with Standpipe for Variable (Falling) HeadTestD1987 07 (2012)39.1.5 If a screen or gravel of approximately 50 mm (2 in.)size is necessary to support the geotextile it must be placedwith the device in an inverted position.9.1.6 Place the lower

46、 end cap on the device and make itsseal.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 end cap on the device and make apermanent seal

47、.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 the

48、system. 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 prescribed value used in the permittivity test of Test MethodD4491. Other values of

49、head or hydraulic gradient, as mutually decidedupon by the parties involved, could also be used.9.1.11 Convert the liquid collected from the discharge tubeto flow rate (liters/min or gal/min) and repeat the measurementthree times. Report the average of this value.9.1.12 Increase the total head lost if desired. Heads of 100mm (4.0 in.), 200 mm (8.0 in.), and 300 mm (12.0 in.) mightbe considered. These relatively high values of total head maybe required if the geotextile begins to clog.9.1.13 After readings are completed, disconnect the headcontrol devices.