1、Designation:D551102 Designation: D5511 11Standard Test Method forDetermining Anaerobic Biodegradation of Plastic MaterialsUnder High-Solids Anaerobic-Digestion Conditions1This standard is issued under the fixed designation D5511; the number immediately following the designation indicates the year of
2、original 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 test method covers the determination of the degree and
3、 rate of anaerobic biodegradation of plastic materials inhigh-solids anaerobic conditions. The test materials are exposed to a methanogenic inoculum derived from anaerobic digestersoperating only on pretreated household waste. The anaerobic decomposition takes place under high-solids (more than 30 %
4、 totalsolids) and static non-mixed conditions.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 found in high-solids anaerobic digesters, treating municipal solid waste (1, 2, 3, 4).2This test method may alsores
5、embles omther anaerobic conditions in biologically active landfills where the gas generated is recovered and biogas productionis even actively promoted, for example, promoted by inoculation (for example, codeposition of anaerobic sewage sludge, anaerobicleachate recirculation), moisture control in t
6、he landfill (leachate (for example, leachate recirculation), and temperature control (forexample, short-term injection of oxygen, heating of recirculated leachate) (5, 6, 7).1.3 This test method is designed to be applicable to all plastic materials that are not inhibitory to the microorganisms prese
7、ntin anaerobic digesters operating on household waste.1.4The values given in SI units are to be regarded as the standard.1.5This test method is equivalent to ISO DIS15985.1.4 Claims of performance shall be limited to the numerical result obtained in the test and not be used for unqualified“biodegrad
8、able” 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 given in SI units are to be regarded as t
9、he 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 and health practices and determine the applicability of regulatorylimitations prior to use. Spec
10、ific hazards are given in Section 8.NOTE 1This test method is equivalent to ISO 15985.2. Referenced Documents2.1 ASTM Standards:3D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1293 Test Methods for pH of WaterD1888 Test Methods for Particulate and Dissolved
11、Matter, Solids, or Residue in WaterD2908 Practice for Measuring Volatile Organic Matter in Water by Aqueous-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 Dete
12、ctionE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relationships2.2 APHA-AWWA-WPCF Standards:1This test method is under the jurisdiction of ASTM Committee of D20 on Plastics and is the direct responsibility of Subcommittee D20.96 on EnvironmentallyD
13、egradable Plastics and Biobased Products.Current edition approved Aug. 10, 2002. Published October 2002. Originally published as D551194. Last previous edition D551194. DOI: 10.1520/D5511-02.Current edition approved Feb. 1, 2011. Published February 2011. Originally approved in 1994. Last previous ed
14、ition approved in 2002 as D5511 02. DOI:10.1520/D5511-11.2The boldface numbers is parentheses refer to a list of references at the end of the text.3For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standards
15、volume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to
16、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 considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
17、ohocken, PA 19428-2959, United States.2540 D D Total Suspended Solids Dried at 103105C42540 E E Fixed and Volatile Solids Ignited at 550C4212 Nitrogen Ammonia42.3 ISO Standard:ISO DIS 15985Plastics Determination of the Ultimate Anaerobic Biodegradability and Disintegration Under High-SolidsAnaerobic
18、-Digestion Conditions Method by Analysis of Released Biogas5ISO 13641-1 Water qualityDetermination of inhibition of gas production of anaerobic bacteriaPart 1: General testISO 15985 PlasticsDetermination of the ultimate anaerobic biodegradability and disintegration under high-solids anaerobic-digest
19、ion conditionsMethod by analysis of released biogas3. Terminology3.1 Definitions Definitions of terms applying to this test method appear in Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 methanogenic inoculumanaerobically digested organic waste containing a high concentra
20、tion of anaerobic methane-producing microorganisms.4. Summary of Test Method4.1 This test method consists of selection and analysis of material for testing, obtaining a concentrated anaerobic inoculum froman anaerobic laboratory-scale digester, exposing the material to an anaerobic-static-batch ferm
21、entation at more than 20 % solids,measuring total carbon in the gas (CO2and CH4) evolved as a function of time, and assessing the degree of biodegradability.4.2 The percentage of biodegradability is obtained by determining the percent of conversion of carbon from the test materialto carbon in the ga
22、seous phase (CH4and 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 CO2and CH4.5. Significance and Use5.1 Biodegradation of a plastic within a high-solids anaerobic diges
23、tion unit is an important phenomenon because it will affectthe decomposition of other waste materials enclosed by the plastic and the resulting quality and appearance of the compost afteran anaerobic digestion process. Biodegradation of plastics could allow for the safe disposal of these plastics th
24、rough aerobic andanaerobic solid-waste-treatment plants. This procedure has been developed to permit the determination of the rate and degree ofanaerobic biodegradability of plastic products when placed in a high-solids anaerobic digester for the production of compost frommunicipal solid waste.5.2 L
25、imitationsBecause there is a wide variation in the construction and operation of anaerobic-digestion systems and becauseregulatory requirements for composting systems vary, this procedure is not intended to simulate the environment of any particularhigh-solids anaerobic-digestion system. However, it
26、 is expected to resemble the environment of a high-solids anaerobic-digestionprocess operated under optimum conditions. More specifically, the procedure is intended to create a standard laboratoryenvironment that will permit a rapid and reproducible determination of the anaerobic biodegradability un
27、der high-solids digestionconditions.6. Apparatus6.1 Inverted Graduated Cylinder or Plastic Column, in water or other suitable device for measuring gas volume. The water incontact with the gas must be at a pH of less than two during the whole period of the test to avoid CO2loss through dissolutionin
28、the water. The gas-volume-measuring device, as well as the gas tubing, shall be of sufficient quality to prevent gas migrationand diffusion between the system and the surrounding air (see Fig. 1).6.2 Gas Chromatograph, (optional) or other apparatus, equipped with a suitable detector and column(s) fo
29、r measuring methaneand carbon dioxide concentration in the evolved gases.6.3 Incubator, or hot-water bath capable of maintaining the test bottles at 52C (62C) for the duration of the test.6.4 Erlenmeyer Flasks, with sufficient capacity for the experiment and openings of at least 7-cm diameter, set u
30、p so that no lossof gas occurs.6.5 pH Meter, precision balance (60.1 g), analytical balance (60.1 mg), thermometer, and barometer.6.6 Devices, suitable for determining volatile fatty acids by aqueous-injection chromatography, total Kjeldahl nitrogen,ammonia nitrogen, dry solids (105C) and volatile-s
31、olids (550C) concentrations.7. Reagents and Materials7.1 Anaerboic Inoculum, derived from a properly operating anaerobic digester with pretreated household waste as a solesubstrate.4Standard Methods for the Examination of Water and Wastewater, 17th Edition, 1989, American Public Health Association,
32、1740 Broadway, New York, NY 10018.5Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.D5511 1127.2 Analytical-Grade Cellulose , for thin-layer chromatography as a positive control.7.3 Polyethylene, as a negative control (optional). It should be
33、is optimal if it is in the same form as the form in which the sampleis tested (for example, film polyethylene for film samples, pellets of polyethylene if the sample is in the form of pellets, etc.).8. Hazards8.1 The procedure given in this test method involves the use of an inoculum composed of bio
34、logically and possibly chemicallyactive materials known to produce a variety of diseases.Avoid contact with these materials by wearing gloves and other appropriateprotective garments. Use good personal hygiene to minimize exposure.8.2The 8.2 It is possible that the solid-waste mixture may containcon
35、tains sharp objects. Take extreme care when handling thismixture to avoid injury.8.3 The biological reactor is not designed to withstand high pressures; operate it at close to ambient pressure.8.4 This test method includes the use of hazardous chemicals. Avoid contact with the chemicals and follow t
36、he manufacturersinstructions and Material Safety Data Sheets.8.5 The methane produced during this 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 must be derived fr
37、om a properly operating anaerobic digester functioning with a pretreated household wasteas a sole substrate. The pretreated household waste shouldshall come from an existing waste treatment facility treating municipalsolid waste, where through sorting, shredding, sieving, or other means, a fairly ho
38、mogeneous organic fraction is produced of lessthan 60 mm. The digester shouldshall be operating for a period of at least four months on the organic fraction, with a retentiontime of a maximum of 30 days under thermophilic conditions (52 6 2C). Gas-production yields shouldshall be at least 15 mLat st
39、andard temperature and pressure of biogas per gram of dry solids in the digester and per day on the average for at least 30days.9.1.1The inoculum should be derived preferably 9.1.1 It is preferable to derive the inoculum from a digester operating underdry (20 % total solids) conditions, or can be de
40、rived but it is acceptable to derive it from a wet fermentation whereby theanaerobically digested sludge is dewatered through centrifugation, with a press or through drying at a maximum temperature of55C to a dry-solids content of at least 20 %.9.2 The prepared inoculum shouldshall undergo a short p
41、ost-fermentation of approximately seven days at the same operatingtemperature from which it was derived. This means that the inoculum is not fed but allowed to post-ferment anaerobically by itself.This is to ensure that large easily biodegradable particles are degraded during this period and also to
42、 reduce the background levelof degradation of the inoculum itself.9.2.1 The most important biochemical characteristics of the inoculum shall be as follows:9.2.1.1 pHBetween 7.5 and 8.5 (in accordance with Test Methods D1293),9.2.1.2 Volatile Fatty Acids (VFA)Below 1 g/kg wet weight (in accordance wi
43、th Practice D2908), and9.2.1.3 NH4+-NBetween 0.5 and 2 g/kg wet weight (in accordance with APHA Test Method 212 and Test Method D3590).9.3 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. T
44、est Specimen10.1 The test specimen shouldshall be of sufficient carbon content, analyzed in accordance with Test Method D4129, to yieldcarbon dioxide and methane volumes that can be accurately measured by the trapping devices described. Add more test specimenFIG. 1 Test SetupD5511 113when low biodeg
45、radability is expected, up to 100 g on a dry weight basis of the test specimen.10.2The 10.2 It is acceptable if the test specimen may beis in the form of films, powder, pellets, formed articles, or in the formof a dog bone and conforming to Practice D618. The test set-up shouldshall be able to handl
46、e articles that are 100 mm by 50 mmby 4 mm thick.11. Procedure11.1 Inoculum Medium:11.1.1 Remove enough inoculum (approximately 15 kg) from the post-fermentation vessel and mix carefully and consistentlyby hand in order to obtain a homogeneous medium.11.1.2 Test three replicates each of a blank (ino
47、culum only), positive control (thin-layer chromatography cellulose), negativecontrol (polyethylene), and the test substance being evaluated.11.1.2.1 Manually mix 1000 g wet weight (at least 20 % dry solids) of inoculum in a small container for a period of 2 to 3 minwith 15 to 100 g of volatile solid
48、s of the test substance or the controls for each replicate. (Determine dry solids and volatile solidsin accordance with APHA Standards 2540 D and 2540 E, ;, and Test Method D1888).11.1.2.2 For the three blanks containing inoculum only, manually mix 1000 g of the same inoculum in a small container fo
49、r aperiod of 2 to 3 min with the same intensity as was done for the other vessels containing test substance or controls.11.1.2.3 Determine the weight of the inoculum and test substance added to each individual Erlenmeyer flask accurately.11.1.2.4 If formed plastic articles are added, it is possible that a specific number of articles may be added and retrieved at theend of the digestion period.11.1.3 Add the mixtures to a 2-L wide-mouth Erlenmeyer flask and gently spread and compact the material evenly in the flaskto a uniform density.11.1.4 After placing
