1、Designation: D5886 95 (Reapproved 2018)Standard Guide forSelection of Test Methods to Determine Rate of FluidPermeation Through Geomembranes for SpecificApplications1This standard is issued under the fixed designation D5886; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, 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 guide covers selecting one or more appropriate testmethods
3、to assess the permeability of all candidate geomem-branes for a proposed specific application to various per-meants. The widely different uses of geomembranes as barriersto the transport and migration of different gases, vapors, andliquids under different service conditions require determina-tions o
4、f permeability by test methods that relate to and simulatethe service. Geomembranes are nonporous, homogeneous ma-terials that are permeable in varying degrees to gases, vapors,and liquids on a molecular scale in a three-step process by: (1)dissolution in or absorption by the geomembrane on theupstr
5、eam side, (2) diffusion through the geomembrane, and (3)desorption on the downstream side of the barrier.1.2 The rate of transmission of a given chemical species,whether as a single permeant or in mixtures, is driven by itschemical potential or in practical terms by its concentrationgradient across
6、the geomembrane. Various methods to assessthe permeability of geomembranes to single componentpermeants, such as individual gases, vapors, and liquids arereferenced and briefly described.1.3 Various test methods for the measurement of permeationand transmission through geomembranes of individual spe
7、ciesin complex mixtures such as waste liquids are discussed.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, health, and environmental practices and deter-m
8、ine the applicability of regulatory limitations prior to use.1.5 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-mendation
9、s issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D471 Test Method for Rubber PropertyEffect of LiquidsD814 Test Method for Rubber PropertyVapor Transmis-sion of Volatile LiquidsD815 Test Method for Testing Coated Fabrics H
10、ydrogenPermeance (Withdrawn 1987)3D1434 Test Method for Determining Gas Permeability Char-acteristics of Plastic Film and SheetingD4439 Terminology for GeosyntheticsD4491/D4491M Test Methods for Water Permeability ofGeotextiles by PermittivityE96/E96M Test Methods for Water Vapor Transmission ofMate
11、rialsF372 Test Method for Water Vapor Transmission Rate ofFlexible Barrier Materials Using an Infrared DetectionTechnique (Withdrawn 2009)3F739 Test Method for Permeation of Liquids and Gasesthrough Protective Clothing Materials under Conditions ofContinuous Contact3. Terminology3.1 Definitions:3.1.
12、1 downstream, nthe space adjacent to the geomem-brane through which the permeant is flowing.3.1.2 geomembrane, nan essentially impermeable geosyn-thetic composed of one or more synthetic sheets. (See Termi-nology D4439.)3.1.2.1 DiscussionIn geotechnical engineering, “essen-tially impermeable” means
13、that no measurable liquid flowsthrough a geosynthetic when tested in accordance with TestMethods D4491/D4491M.1This guide is under the jurisdiction ofASTM Committee D35 on Geosyntheticsand is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved Feb. 1, 2018. Publ
14、ished February 2018. Originallyapproved in 1995. Last previous edition approved in 2011 as D5886 95 (2011).DOI: 10.1520/D5886-95R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
15、ation, refer to the standards Document 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
16、developed in accordance with internationally 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.13.1.3 geosynth
17、etic, na planar product manufactured frompolymeric material used with soil, rock, earth, or other geo-technical engineering-related material as an integral part of aman-made project, structure, or system. (See TerminologyD4439.)3.1.4 permeability, nthe rate of flow under a differentialpressure, temp
18、erature, or concentration of a gas, liquid, orvapor through a material. (Modified fromTest Methods D4491/D4491M.)3.1.5 permeant, na chemical species, gas, liquid, or vaporthat can pass through a substance.4. Summary of Guide4.1 The wide range of uses of geomembranes as barriers inmany different envi
19、ronments to many different permeatingspecies requires different test procedures to assess the effec-tiveness of a given membrane for a given application. Thepermeating species range from a single component to highlycomplex mixtures such as those found in waste liquids andleachates. In specialized ap
20、plications, it may be important tomeasure transmission or migration of a species that would takeplace under specific conditions and environments includingtemperature, vapor pressure, and concentration gradients. Teststhat would be applicable to the measurement of the permeabil-ity of a material to d
21、ifferent permeants present in variousapplications are summarized in Table 1.4.1.1 In the use of geomembranes in service as barriers tothe transmission of fluids, it is essential to recognize thedifference between geomembranes that are nonporous, homo-geneous materials and other liner materials that
22、are porous,such as soils and concretes. The transmission of permeatingspecies through geomembranes without holes proceeds byabsorption of the species in the geomembrane and diffusionthrough the geomembrane on a molecular basis. The drivingforce is chemical potential across the geomembrane. A liquidp
23、ermeates porous materials in a condensed state that can carrythe dissolved constituents, and the driving force for suchpermeation is hydraulic pressure. Due to the selective nature ofgeomembranes, the permeation of the dissolved constituents inliquids can vary greatly, that is, components of a mixtu
24、re canpermeate at different rates due to differences in solubility anddiffusibility in a given geomembrane. With respect to theinorganic aqueous salt solution, the geomembranes aresemipermeable, that is, the water can be transmitted throughthe geomembranes, but the ions are not transmitted. Thus, th
25、ewater that is transmitted through a hole-free geomembranedoes not carry dissolved inorganics. The direction of perme-ation of a component in the mixture is determined thermody-namically by its chemical potential difference or concentrationgradient across the geomembrane. Thus, the water in thewaste
26、water on the upstream side is at a lower potential than theless contaminated water on the downstream side and canpermeate the geomembrane into the wastewater by osmosis.4.1.2 Although inorganic salts do not permeategeomembranes, some organic species do. The rate of perme-ation through a geomembrane
27、depends on the solubility of theorganic in the geomembrane and the diffusibility of the organicin the geomembrane as driven by the chemical potentialgradient. Principle factors that can affect the diffusion of anorganic within a geomembrane include:4.1.2.1 The solubility of the permeant in the geome
28、mbrane,4.1.2.2 The microstructure of the polymer, for example,percent crystallinity,4.1.2.3 Whether the condition at which diffusion is takingplace is above or below the glass transition temperature of thepolymer,4.1.2.4 The other constituents in the geomembranecompound,4.1.2.5 Variation in manufact
29、uring processes,4.1.2.6 The flexibility of the polymer chains,4.1.2.7 The size and shape of the diffusing molecules,TABLE 1 Applicable Test Method for Measuring Permeability of Geomembranes to Various PermeantsFluid Being Contained Example of Permeant Example of Field ApplicationApplicable Test Meth
30、od and PermeantDetector and QuantifierSingle-Component Fluids:Gas H2,O2Barriers, pipe, and hose liners D815N2,CH4D1434-VCO2D1434-PWater vapor H2O Moisture vapor barriers, water reservoircoversE96/E96M, D653Liquid water H2O Liners for reservoirs, dams, and canals Soil-type permeameter with hydraulicp
31、ressureOrganic vapor Organic species Secondary containment for organic sol-vent and gasolineD814, E96/E96M, F372Organic liquid Organic solvents species Containers, tank liners secondary con-tainmentD814, E96/E96MMulticomponents Fluids:Gases CO2/CH4Barriers, separation of gases F372, GC, GCMSAqueous
32、solutions of inorganic, forexample, brines, incinerator ashleachates, leach pad leachateIons, salts Pond liners Pouch, osmotic cell, ion analysisMixtures of organics, spills, hydrocar-bon fuelsOrganic species Liners for tanks and secondary contain-mentE96/E96M with headspace, GCAqueous solutions of
33、organics Organic species, H2O Liners for ponds and waste disposal Pouch, Multicompartment cell withanalysis by GC on GCMSComplex aqueous solutions of organicsand inorganic speciesH2O, organic species, dissolved salts Liners for waste disposal Pouch, Multicompartment cell, osmoticcell, analysis by he
34、ad-space GCD5886 95 (2018)24.1.2.8 The temperature at which diffusion is taking place,and4.1.2.9 The geomembrane.4.1.3 The movement through a hole-free geomembrane ofmobile species that would be encountered in service would beaffected by many factors, such as:4.1.3.1 The composition of the geomembra
35、ne with respectto the polymer and to the compound,4.1.3.2 The thickness of the geomembrane,4.1.3.3 The service temperature,4.1.3.4 The temperature gradient across the geomembranein service,4.1.3.5 The chemical potential across the geomembrane,that includes pressure and concentration gradient,4.1.3.6
36、 The composition of the fluid and the mobileconstituents,4.1.3.7 The solubility of various components of an organicliquid in the particular geomembrane that increase concentra-tion of individual components on the upstream side of thegeomembrane and can cause swelling of the geomembraneresulting in i
37、ncreased permeability,4.1.3.8 The ion concentration of the liquid, and4.1.3.9 Ability of the species to move away from the surfaceon the downstream side.4.1.4 Because of the great number of variables, it is impor-tant to perform permeability tests of a geomembrane underconditions that simulate as cl
38、osely as possible the actualenvironmental conditions in which the geomembrane will be inservice.5. Significance and Uses5.1 The principal characteristic of geomembranes is theirintrinsically low permeability to a broad range of gases, vapors,and liquids, both as single-component fluids and as comple
39、xmixtures of many constituents. As low-permeable materials,geomembranes are being used in a wide range of engineeringapplications in geotechnical, environmental, and transportationareas as barriers to control the migration of mobile fluids andtheir constituents. The range of potential permeants is b
40、roadand the service conditions can differ greatly. This guide showsusers test methods available for determining the permeabilityof geomembranes to various permeants.5.2 The transmission of various species through a geomem-brane is subject to many factors that must be assessed in orderto be able to p
41、redict its effectiveness for a specific service.Permeability measurements are affected by test conditions, andmeasurements made by one method cannot be translated fromone application to another.Awide variety of permeability testshave been devised to measure the permeability of polymericmaterials; ho
42、wever, only a limited number of these procedureshave been applied to geomembranes. Test conditions andprocedures should be selected to reflect actual service require-ments as closely as possible. It should be noted that fieldconditions may be difficult to model or maintain in thelaboratory. This may
43、 impact apparent performance of geomem-brane samples.5.3 This guide discusses the mechanism of permeation ofmobile chemical species through geomembranes and the per-meability tests that are relevant to various types of applicationsand permeating species. Specific tests for the permeability ofgeomemb
44、ranes to both single-component fluids and multicom-ponent fluids that contain a variety of permeants are describedand discussed.6. Basis of Classification6.1 Even though geomembranes are nonporous and cannotbe permeated by liquids as such, gases and vapors of liquidscan permeate a geomembrane on a m
45、olecular level. Thus, evenif a geomembrane is free of macroscopic holes, some compo-nents of the contained fluid can permeate and might escape thecontainment unit.6.2 The basic mechanism of permeation through geomem-branes is essentially the same for all permeating species. Themechanism differs from
46、 that through porous media, such assoils and concrete, which contain voids that are connected insuch a way that a fluid introduced on one side will flow fromvoid to void and emerge on the other side; thus, a liquid canflow through the voids and carry dissolved species.6.3 Overall rate of flow throug
47、h saturated porous mediafollows Darcys equation that states that the flow rate isproportional to the hydraulic gradient, as is shown in thefollowing equation:Q 5 kiA (1)where:Q = rate of flow,k = constant (Darcys coefficient of permeability),A = total inside cross-sectional area of the samplecontain
48、er, andi = hydraulic gradient.6.4 With most liquids in saturated media, the flow followsDarcys equation; however, the flow can deviate due tointeractions between the liquid and the surface of the soilparticles. These interactions become important in the escape ofdissolved species through a low-perme
49、ability, porous linersystem in a waste facility. Dissolved chemical species, eitherorganic or inorganic, not only can permeate such a mediumadvectively (that is, the liquid acts as the carrier of thechemical species), but also by diffusion in accordance withFicks two laws of diffusion.6.5 Even though polymeric geomembranes are manufac-tured as solid homogeneous nonporous materials, they containinterstitial spaces between the polymer molecules throughwhich small molecules can diffuse. Thus, all polymericgeomembranes are permeable to a degree.Apermeant migratesthrough the
