1、Designation: D5511 12D5511 18Standard 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 oforiginal ado
2、ption 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. Scope Scope*1.1 This test method covers the determination of the degree and rate
3、 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 % tota
4、lsolids) 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).2 This test method may also resemb
5、lesome conditions in biologically active landfills where the gas generated is recovered and biogas production is actively promotedby inoculation (for example, codeposition of anaerobic sewage sludge, anaerobic leachate recirculation), moisture control (forexample, leachate recirculation), and temper
6、ature control (for example, short-term injection of oxygen, heating of recirculatedleachate) (5, 6, 7).1.3 This test method is designed to be applicable to all plastic materials that are not inhibitory to the microorganisms presentin anaerobic digesters operating on household waste.1.4 Claims of per
7、formance shall be limited to the numerical result obtained in the test and not be used for unqualified“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 n
8、ot be extrapolated past the actual duration of the test.1.5 The values given in SI units are to 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 app
9、ropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use. Specific hazards are given in Section 8.NOTE 1This test method is equivalent to ISO 15985.1.7 This international standard was developed in accordance with internat
10、ionally recognized principles on standardizationestablished in the Decision on 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 Pract
11、ice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1293 Test Methods for pH of WaterD1888 Methods Of Test for Particulate and Dissolved Matter in Water (Withdrawn 1989)4D2908 Practice for Measuring Volatile Organic Matter in Water by Aqueous-Injection Gas ChromatographyD3
12、590 Test Methods for Total Kjeldahl Nitrogen in Water1 This test method is under the jurisdiction of ASTM Committee of D20 on Plastics and is the direct responsibility of Subcommittee D20.96 on EnvironmentallyDegradable Plastics and Biobased Products.Current edition approved May 1, 2012Jan. 15, 2018
13、. Published June 2012February 2018. Originally published asapproved in D5511 94.1994. Last previous editionapproved in 2012 as D5511 11.D5511 12. DOI: 10.1520/D5511-12.10.1520/D5511-18.2 The boldface numbers is parentheses refer to a list of references at the end of the text.3 For referencedASTM sta
14、ndards, visit theASTM website, 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.4 The last approved version of this historical standard is referenced on www.astm.org
15、.This 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 adequately depict all changes accurately, ASTM recommends that users consult prior ed
16、itions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29
17、59. United States1D4129 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 Relationships2.2 APHA-AWWA-WPCF Standards:2540 D Total Suspended Solids
18、 Dried at 103105C52540 E Fixed and Volatile Solids Ignited at 550C5212 Nitrogen Ammonia52.3 ISO Standard:6ISO 13641-1 Water qualityDetermination of inhibition of gas production of anaerobic bacteriaPart 1: General testISO 15985 PlasticsDetermination of the ultimate anaerobic biodegradability and dis
19、integration under high-solids anaerobic-digestion conditionsMethod by analysis of released biogas3. Terminology3.1 DefinitionsDefinitions 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 diges
20、ted organic waste containing a high concentration 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 t
21、he material to an anaerobic-static-batch fermentation at more than 20 % solids,measuring total carbon in the gas (CO2 and 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 ca
22、rbon from 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 Biodegradation o
23、f a plastic within a high-solids anaerobic digestion 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 digestate afteran anaerobic digestion process. Biodegradation of plastics coul
24、d allow for the safe disposal of these plastics through 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 pro
25、duction of digestate frommunicipal solid waste.5.2 LimitationsBecause 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 particula
26、rhigh-solids anaerobic-digestion system. However, it 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 reproducibl
27、e determination of the anaerobic biodegradability under 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
28、 of the test to avoid CO2 loss through dissolutionin 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 apparatu
29、s, equipped with a suitable detector and column(s) for measuring methaneand carbon dioxide concentration in the evolved gases.6.3 Incubator, or hot-water bath capable of maintaining the test bottles at 37C (62C) or 52C (62C) for the duration of thetest.6.4 Erlenmeyer Flasks, with sufficient capacity
30、 for the experiment and openings of at least 7-cm diameter, set up so that no lossof gas occurs.6.5 pH Meter, precision balance (60.1 g), analytical balance (60.1 mg), thermometer, and barometer.5 Standard Methods for the Examination of Water and Wastewater, 17th Edition, 1989, American Public Healt
31、h Association, 1740 Broadway, New York, NY 10018.6 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.D5511 1826.6 Devices, suitable for determining volatile fatty acids by aqueous-injection chromatography, total Kjeldahl ni
32、trogen,ammonia nitrogen, dry solids (105C) and volatile-solids (550C) concentrations.7. Reagents and Materials7.1 Anaerboic Inoculum, derived from a properly operating anaerobic digester with pretreated household waste as a solesubstrate.7.2 Analytical-Grade Cellulose, for thin-layer chromatography
33、as a positive control.7.3 Polyethylene, as a negative control (optional). It is optimal if it is in the same form as the form in which the sample is 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 proced
34、ure given in this test method involves the use of an inoculum composed of biologically 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 e
35、xposure.8.2 It is possible that the solid-waste mixture contains sharp objects. Take extreme care when handling this mixture to avoidinjury.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 hazardo
36、us chemicals. Avoid contact with the chemicals and follow the 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
37、or to a hood.9. Inoculum9.1 The inoculum must be derived from a properly operating anaerobic digester functioning with a pretreated household wasteas a sole substrate. The pretreated household waste shall come from an existing waste treatment facility treating municipal solidwaste, where through sor
38、ting, shredding, sieving, or other means, a fairly homogeneous organic fraction is produced of less than60 mm. The digester shall be operating for a period of at least four months on the organic fraction, with a retention time of amaximum of 30 days under thermophilic conditions (52 6 2C). Gas-produ
39、ction yields shall be at least 15 mL at standardtemperature and pressure of biogas per gram of dry solids in the digester and per day on the average for at least 30 days.9.1.1 It is preferable to derive the inoculum from a digester operating under dry (20 % total solids) conditions, but it isaccepta
40、ble to derive it from a wet fermentation whereby the anaerobically digested sludge is dewatered through centrifugation,with a press or through drying at a maximum temperature of 55C to a dry-solids content of at least 20 %.9.2 The prepared inoculum shall undergo a short post-fermentation of approxim
41、ately 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 reduce the background level
42、of degradation of the inoculum itself.9.2.1 The most important biochemical characteristics of the inoculum shall be as follows:FIG. 1 Test SetupD5511 1839.2.1.1 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 with
43、 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. Tes
44、t Specimen10.1 The test specimen shall be of sufficient carbon content, analyzed in accordance with Test Method D4129, to yield carbondioxide and methane volumes that can be accurately measured by the trapping devices described. Add more test specimen whenlow biodegradability is expected, up to 100
45、g on a dry weight basis of the test specimen.10.2 It is acceptable if the test specimen is in the form of films, powder, pellets, formed articles, or in the form of a dog boneand conforming to Practice D618. The test set-up shall be able to handle articles that are 100 mm by 50 mm by 4 mm thick.11.
46、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 (inoculum only), positive control (thin-layer chromatogra
47、phy 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 solids of the test substance or the controls for each repl
48、icate. (Determine dry solids and volatile solidsin accordance with APHA Standards , 2540, 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 for aperiod of 2 to 3 min with the same intensity as was done for the
49、 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 be added and retrieved at the endof 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 the Erlenmeyer flask in a water bath or incubator, connect it with
