1、Designation: D 1987 07Standard Test Method forBiological Clogging of Geotextile or Soil/Geotextile Filters1This standard is issued under the fixed designation D 1987; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 is used to determine the potential for,and relative degree of, biological growth which can accumulateon
3、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 head or falling he
4、admeasurement 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 provided in inch-pound
5、 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 regulatory limitatio
6、ns prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 4354 Practice for Sampling of Geosynthetics for TestingD 4439 Terminology for GeosyntheticsD 4491 Test Methods for Water Permeability of Geotextiles
7、by PermittivityD 5101 Test Method for Measuring the Soil-GeotextileSystem Clogging Potential by the Gradient RatioG22 Practice for Determining Resistance of Plastics toBacteria3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definiti
8、ons: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 conductivity.3.1.3 permittivity, (C)(t1), nof geotextiles, t
9、he volumet-ric flow rate of water per unit, in a cross sectional area headunder laminar 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, this condition can po-tentially contribute to the gr
10、owth 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 flushing, na process by which liquid is forcedin the r
11、everse 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 kill bacteria and othermicroorganisms.3.2 For definiti
12、ons of other terms used in this test method,refer to Terminology D 123 and D 4439.4. 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 cond
13、itions.4.1.1 The designated liquid might contain micro-organismsfrom which biological growth can occur.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 Sept. 15,
14、 2007. Published October 2007. Originallyapproved in 1991. Last previous edition approved in 2002 as D 1987 95(2002).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
15、 the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 Flow rate is measured over time, converted to eitherpermittivity or permeability, and reported according.4.2.1 Bet
16、ween readings, the test specimen can be allowed tobe in either nonsaturated or saturated conditions.4.2.2 Back 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 w
17、ithin the test specimen, and evaluatedaccordingly.5. Significance and Use5.1 This test method is performance oriented 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
18、 oriented towardlandfill leachates but can be performed with any liquid comingfrom a particular site or synthesized 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 Th
19、is test will usually take considerable time, for ex-ample, up to 1000 h, for the biological activity to initiate, grow,and reach an equilibrium condition. The curves resulting fromthe test are intended to indicate the in situ behavior of ageotextile or soil/geotextile filter.5.4 The test specimen ca
20、n be incubated under non-saturateddrained conditions between readings, or kept saturated at alltimes. The first case 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 rat
21、e 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 thegeotextile or soil/geotextile is the same, only the head controldevices change.NOTE 1It has been found that once biological clogging initiates,
22、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 basis of time of movement of a relatively small quantityof liquid between two designated points on a clear plastic standpipe.5.6 If the
23、 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 biocide.5.7 The resulting flow rate curves are intended for use in thedesign of full scale geotextile or soil/geotextile filtrationsystems
24、 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 100mm (4.0 in.) inside diameter containment ring for placement ofthe geotextile specimen along with upper and lower flow tubesto allow for
25、 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 madesufficiently long so as to provide for a soil column to be placedabove the geotextile. When this type of combined soil/geotextile c
26、ross section is used, however, it is difficult todistinguish which material is clogging, for example, the soil 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 thedif
27、ference 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 material (soil or solid waste)located above the filter are desired, the upper flow column of thepermeameter can be modified to accommodate
28、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.Duplicate ports on each side of the permeameter at the above elevationsare considered good practice in measurements of this type. Otherconf
29、igurations 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 measurements of this type. See TestMethod D 5101, the Gradient Ratio test, for additional details.6.2 Hydraulic head control devices, are r
30、equired at both theinlet and outlet ends of the flow column. Fig. 2 shows thecomplete setup based on constant hydraulic head monitoringwhere concentric plastic cylinders are used with the innercylinders being at the elevation from which head is measured.The elevation difference between the inner cyl
31、inder 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 combined test column). Note that theelevation of the outlet must be above the elevation of thegeotextile.6.3 A hydraulic head standpip
32、e, above the flow column isrequired for falling hydraulic 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.FIG. 1 Flow Column to Cont
33、ain Geotextile Test SpecimenD1987072Note that the elevation of the outlet must be above theelevation of the geotextile.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
34、 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 specific andoften comprises landfill leachate. Other liquids for whichbiological clogging is of concern can also be evaluated. Theliquid can b
35、e synthesized on an as-required basis.NOTE 3A synthesized liquid which has been used in determining theresistance 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 SampleDiv
36、ide the product into lots and take thelot sample as directed in Practice D 4354.7.2 Laboratory SampleFor the laboratory 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
37、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 outer wrap material may beused.7.3 Test SpecimensFrom the laboratory sample select thenumber of specimens as per the number of flow columns
38、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 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 a
39、round 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 one and theconditions of the permeating fluid will be the controlling factor.See also Practice D 1776.8.2 The relative humidity should be 100 %
40、 except duringtimes of air drying between nonsaturated test readings. Forsaturated conditions the relative humidity 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 regu
41、lar 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 the 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
42、 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 insideof the containment ring using a silicon based caulk and allowit to completely cure. The caulk must be carefully placed so asnot to re
43、strict 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 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 i
44、n.)size is necessary to support the geotextile it must be placedwith the device in an inverted position.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 O
45、utlet Hydraulic Head ControlDevices for Constant Head TestFIG. 3 Flow Column with Standpipe for Variable (Falling) HeadTestD19870739.1.6 Place the lower 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 mois
46、ture 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.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 sho
47、wn 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 su
48、ggested to use 50 mm (2 in.) total head difference sincethis is the prescribed value used in the permittivity test of Test MethodD 4491. Other values of head or hydraulic gradient, as mutually decidedupon by the parties involved, could also be used.9.1.11 Convert the liquid collected from the discha
49、rge 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. If non-saturated (aerobic) conditions are de-sired, the bottom end cap outlet is allowed to vent to theatmosphere. If saturated conditions are desired,
