1、Designation: D5526 12D5526 18Standard Test Method forDetermining Anaerobic Biodegradation of Plastic MaterialsUnder Accelerated Landfill Conditions1This standard is issued under the fixed designation D5526; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n 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 test method covers determination of the degree and rate of anaerobic biodegra
3、dation of plastic materials in anaccelerated-landfill test environment. This test method is also designed to produce mixtures of household waste and plasticmaterials after different degrees of decomposition under conditions that resemble landfill conditions. The test materials are mixedwith pretreat
4、ed household waste and exposed to a methanogenic inoculum derived from anaerobic digesters operating only onpretreated household waste. The anaerobic decomposition occurs under dry (more than 30 % total solids) and static nonmixedconditions. The mixtures obtained after this test method can be used t
5、o assess the environmental and health risks of plasticmaterials that are degraded in a landfill.1.2 This test method is designed to yield a percentage of conversion of carbon in the sample to carbon in the gaseous form underconditions that resemble landfill conditions. It is possible that this test
6、method will not simulate all conditions found in landfills,especially biologically inactive landfills. This test method more closely resembles those types of landfills in which the gasgenerated is recovered or even actively promoted, or both, for example, by inoculation (codeposition of anaerobic se
7、wage sludgeand anaerobic leachate recirculation), moisture control in the landfill (leachate recirculation), and temperature control (short-terminjection of oxygen and heating of recirculated leachate) (1-7).21.3 This test method is designed to produce partially degraded mixtures of municipal solid
8、waste and plastics that can be usedto assess the ecotoxicological risks associated with the anaerobic degradation of plastics after various stages of anaerobicbiodegradation in a landfill.1.4 Claims of performance shall be limited to the numerical result obtained in the test and not be used for unqu
9、alified“biodegradable” claims. Reports shall clearly state the percentage of net gaseous carbon generation for both the test and referencesamples at the completion of the test. Furthermore, results shall not be extrapolated past the actual duration of the test.1.5 The values stated in SI units are t
10、o be regarded as the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicabili
11、ty of regulatory limitations prior to use. Specific hazards statements are given in Section 8.NOTE 1There is no known ISO equivalent to this standard.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision o
12、n Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to Plastic
13、sD1293 Test Methods for pH of Water1 This test method is under the jurisdiction ofASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.96 on Environmentally DegradablePlastics and Biobased Products.Current edition approved May 1, 2012Sept. 15, 2018. Published June 2012
14、October 2018. Originally approved in 1994. Last previous edition approved in 20112012 asD5526 94D5526 12.(2011) 1. DOI: 10.1520/D5526-12.10.1520/D5526-18.2 The boldface numbers in parentheses refer to the list of references at the end of this standard.3 For referencedASTM standards, visit theASTM we
15、bsite, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indicat
16、ion of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be cons
17、idered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D1888 Methods Of Test for Particulate and Dissolved Matter in Water (Withdrawn 1989)4D2908 Practice for Measuring Volatile Organic Matter in Water by Aqueous
18、-Injection Gas ChromatographyD3590 Test Methods for Total Kjeldahl Nitrogen in WaterD4129 Test Method for Total and Organic Carbon in Water by High Temperature Oxidation and by Coulometric DetectionE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relat
19、ionships2.2 APHA-AWWA-WPCF Standards:52540D Total Suspended Solids Dried at 103105C2540E Fixed and Volatile Solids Ignited at 550C212 Nitrogen Ammonia3. Terminology3.1 DefinitionsFor definitions of terms used in this test method see Terminology D883.3.2 Definitions of Terms Specific to This Standard
20、:3.2.1 methanogenic inoculumanaerobically digested organic waste containing a high concentration of anaerobic methane-producing microorganisms.4. Summary of Test Method4.1 This test method described consists of the following: (1) selecting and analyzing material for testing; (2) obtaining apretreate
21、d municipal-solid-waste fraction and a concentrated anaerobic inoculum from an anaerobic digester; (3) exposing thematerial to an anaerobic static batch fermentation at more than 30 % solids; (4) measuring total carbon in the gas (CO2 and CH4)evolved as a function of time; (5) removing the specimens
22、 for cleaning (optional), conditioning, testing, and reporting; (6)assessing the degree of biodegradability; and (7) assessing the degree of biodegradability under less than optimum conditions.4.2 The percentage of biodegradability is obtained by determining the percent of conversion of carbon from
23、the test materialto carbon in the gaseous phase (CH4 and CO2). This percentage of biodegradability will not include the amount of carbon fromthe test substance that is converted to cell biomass and that is not, in turn, metabolized to CO2 and CH4.5. Significance and Use5.1 Decomposition of a plastic
24、 within a landfill involves biological processes that will affect the decomposition of othermaterials enclosed by, or in close proximity to, the plastic. Rapid degradation of the plastic has the ability to increase the economicfeasibility of landfill-gas recovery, minimize the duration of after-care
25、 of the landfill, and make possible the recovery of the volumereduction of the waste due to biodegradation during the active life of the landfill. This procedure has been developed to permitdetermination of the anaerobic biodegradability of plastic products when placed in biologically active environ
26、ments simulatinglandfill conditions.5.2 As degradation occurs inevitably in a landfill, it is of immediate concern that the plastic materials do not produce toxicmetabolites or end products under the various conditions that have the potential to occur in a landfill. The mixtures remaining aftercompl
27、etion of the test method, containing fully or partially degraded plastic materials or extracts, can be submitted subsequentlyto ecotoxicity testing in order to assess the environmental hazards posed by the breakdown of plastics to varying degrees inlandfills. This test method has been designed to as
28、sess biodegradation under optimum and less-than-optimum conditions.5.3 LimitationsBecause a wide variation exists in the construction and operation of landfills, and because regulatoryrequirements for landfills vary greatly, this procedure is not intended to simulate the environment of all landfills
29、. However, it isexpected to closely resemble the environment of a biologically active landfill. More specifically, the procedure is intended to createa standard laboratory environment that permits rapid and reproducible determination of the anaerobic biodegradability underaccelerated landfill condit
30、ions, while at the same time producing reproducible mixtures of fully and partially decomposedhousehold waste with plastic materials for ecotoxicological assessment.6. Apparatus6.1 Pressure-Resistant Glass VesselsTwenty-seven, each with a volume of 4 to 6 L, which can be closed airtight and capableo
31、f withstanding an overpressure of two atmospheres. The lids of the reactors are equipped with an overpressure valve (to preventthe overpressure from becoming higher than 2 bars), a manometer that provides a rough indication of the overpressure, a septumthat allows one to take gas samples and measure
32、 the exact overpressure, and, finally, a valve to release the overpressure (Fig. 1).6.2 Incubators, sufficient to store the vessels in the dark at 35 6 2C for the duration of the test.4 The last approved version of this historical standard is referenced on www.astm.org.5 Standard Methods for the Exa
33、mination of Water and Wastewater, 20th ed., 1999, available fromAmerican Public HealthAssociation, 800 I Street, NW, Washington, D.C.20001-3710, or http:/www.standardmethods.org.D5526 1826.3 Pressure Transducer, connected to a syringe needle to measure the headspace pressure in the test vessel.6.4 G
34、as Chromatograph, or other apparatus, equipped with a suitable detector and column(s) for measuring methane and carbondioxide concentrations in the evolved gases.6.5 pH Meter, precision balance (60.1 g), analytical balance (60.1 mg), thermometer, and barometer.6.6 Suitable Devices, for determining v
35、olatile fatty acids by aqueous-injection chromatography, total Kjeldahl nitrogen,ammonia nitrogen, dry solids (105C), and volatile solids (550C) concentrations.7. Reagents and Materials7.1 Pretreated-Household Waste, derived from mixed municipal solid waste or the organic fraction thereof, after hom
36、ogenizing,screening over a screen with holes of a diameter of 40 to 80 mm, and aerobically stabilized over a period of 2 to 4 weeks byblowing air into the material and maintaining a dry-matter content of 50 6 5 % and a temperature of 55 6 10C. (Optional: thepretreated household waste can be replaced
37、 by a similarly pretreated simulated solid waste.)7.2 Anaerobic Inoculum, derived from a properly operating anaerobic digester with pretreated household waste as a solesubstrate or a digester that treats predominantly household waste.7.3 Cellulose, Analytical-Grade, for thin-layer chromatography as
38、a positive control.66 Avicel, available from EM Chemicals, Inc., Hawthorne, NY, was used for development of this test method.1 = Digester.2 = Incubation chamber.3 = Overpressure valve.4 = Manometer.5 = Septum.6 = Valve.1 = Digester.2 = Incubation chamber.3 = Overpressure valve.4 = Manometer.5 = Sept
39、um.6 = Valve.FIG. 1 Setup of Accelerated LandfillD5526 1837.4 Polyethylene (optional), as a negative control. It needs to be in the same form as that in which the sample is tested: filmpolyethylene for film samples, pellets of polyethylene in case the sample is in the form of pellets, etc.8. Hazards
40、8.1 This procedure involves the use of inoculum and municipal solid waste containing biologically and possibly chemicallyactive materials known to produce a variety of diseases.Avoid contact with these materials by wearing gloves and other appropriateprotective equipment. Use good personal hygiene t
41、o minimize exposure.8.2 It is possible that the solid waste mixture will contain sharp objects. Take extreme care when handling this mixture to avoidinjury.8.3 This test method includes the use of hazardous chemicals. Avoid contact with the chemicals and follow the manufacturersinstructions and mate
42、rial safety data sheets.8.4 The methane produced during the procedure is explosive and flammable. Upon release of the biogas from the gas-collectionsystem, take care in venting the biogas to the outside or to a hood.9. Inoculum9.1 The inoculum can be derived either from a laboratory-scale or full-sc
43、ale continuous digester or batch digester, operating at35C and functioning with an organic fraction of household waste as the predominant substrate. In case the inoculum is derivedfrom a continuous laboratory-scale or full-scale digester, the digester must be operating for a period of at least one m
44、onth on theorganic fraction of household waste, with a maximum retention time of 30 days under mesophilic conditions (35 6 2C). Gasproduction yields must be at least 15 mL at standard temperature and pressure of biogas/gram of dry solids in the digester and perday for at least 7 days. In case the in
45、oculum is derived from a batch digester, the gas production rate must have exceeded 1 L/kgwaste/day, and the methane concentration of the biogas being produced must be above 60 %.9.2 The prepared inoculum needs to undergo a short mesophilic post-fermentation of approximately 7 days at the samedry-ma
46、tter content as the digester from which it was derived.This means that the inoculum is not fed but is allowed to post-fermentanaerobically by itself. This is to ensure that large, easily biodegradable particles are degraded during this period and also to reducethe background level of degradation of
47、the inoculum itself.9.3 The biochemical characteristics of the inoculum shall be as follows:9.3.1 pHBetween 7.5 and 8.5 (in accordance with Test Methods D1293);9.3.2 Volatile Fatty Acids (VFA)Below 1 g/kg wet weight (in accordance with Practice D2908); and9.3.3 NH+ 4-NBetween 0.5 and 2 g/kg (in acco
48、rdance with APHA Test 212 and Test Method D3590).9.4 Analyses are performed after dilution of the inoculum with distilled water on a ratio of distilled water to inoculum of 5 to1 on a weight-over-weight basis.10. Test Specimen10.1 The test specimen needs to be of sufficient carbon content, analyzed
49、in accordance with Test Method D4129, to yieldcarbon dioxide and methane volumes that can be measured accurately by the trapping devices described. Add more test specimenwhen low biodegradability is expected, up to 100 g of dry matter of the test specimen.10.2 It is acceptable for the test specimen to be in the form of films, powder, pellets, or formed articles, or in the form of a dogbone and in accordance with Practice D618. The test setup needs to be capable of handling articles that are 100 by 50 by 4 mmthick.11. Procedure11.1 Preparation of the Mixtu
