1、Designation:D634098(Reapproved 2007)Standard Test Methods forDetermining Aerobic Biodegradation of Radiolabeled PlasticMaterials in an Aqueous or Compost Environment1This standard is issued under the fixed designation D6340;the number immediately following the designation indicates the year oforigin
2、al 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 These test methods directly determine the rate anddegree of biological o
3、xidation of carbon in plastic materialswhen placed in a composting environment containing simu-lated municipal solid waste or an aqueous environment underlaboratory conditions.1.2 Test Method A utilizes a mixed culture derived from thetarget environment(waste water,sewage sludge,composteluant,and ot
4、her environmental sources).Temperature,mixing,and aeration are monitored and controlled.1.2.1 This method has the sensitivity to determine biodeg-radation at concentrations commonly found in these environ-ments.1.3 Test Method B starts with fresh compost and proceedsthrough the normal composting pro
5、cess to an early maturestage.Temperature,aeration;and moisture are monitored andcontrolled.1.3.1 This method can determine biodegradation at levels ofthe plastic commonly expected in municipal solid waste.1.4 These test methods require that the target component ofthe plastic material be synthesized
6、using the radioactive isotopecarbon-14.Depending upon the objective,either a portion ofthe components of the plastic or all of the carbon can beuniformly labeled with carbon-14.The test method will deter-mine how that labeled portion will be metabolized and bio-logically oxidized by the microorganis
7、ms in the system tested.1.5 These test methods can be applied to any carbon-14labeled compound as well as for plastic materials that havebeen formulated to biodegrade in a natural aerobic environ-ment.1.6 The synthesis and preparation of the radiolabled plasticis beyond the scope of these methods.Ca
8、rbon-14 labeledpolymers may be purchased from a number of commerciallabs.1.7 There are no ISO test methods that are equivalent to thetest methods in this standard.1.8 The safety problems associated with compost and radio-activity are not addressed in this standard.It is the responsi-bility of the us
9、er of this standard to establish appropriate safetyand health practices.It is also incumbent on the user toconform to all the regulatory requirements,specifically thosethat relate to the use of open radioactive sources.1.9 This standard does not purport to address all of thesafety concerns,if any,as
10、sociated 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD5209 Test Method fo
11、r Determining the Aerobic Biodegra-dation of Plastic Materials in the Presence of MunicipalSewage Sludge(Withdrawn 2001)3D5296 Test Method for Molecular Weight Averages andMolecular Weight Distribution of Polystyrene by HighPerformance Size-Exclusion ChromatographyD5338 Test Method for Determining A
12、erobic Biodegrada-tion of Plastic Materials Under Controlled CompostingConditions,Incorporating Thermophilic TemperaturesD5512 Practice for Exposing Plastics to a Simulated Com-post Environment Using an Externally Heated Reactor(Withdrawn 2002)33.Terminology3.1 DefinitionsFor definitions of terms us
13、ed in these testmethods as they relate to composting,see Terminology D883.3.1.1 specific activity,SA,nrefers to the quantity ofradioactivity per mass unit of compound(polymer,etc.),that isdpmh%.1These test methods are under the jurisdiction of Committee D20 on Plastics andare the direct responsibili
14、ty of Subcommittee D20.96 on Environmentally Degrad-able Plastics and Biobased Products.Current edition approved May 1,2007.Published June 2007.Originallyapproved in 1998.Last previous edition approved in 1998 as D6340-98.DOI:10.1520/D6340-98R07.2For referenced ASTM standards,visit the ASTM website,
15、www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,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 Bar
16、r Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2 Acronyms:3.2.1 Bq,nbecquerel;SIunitwhere1curie(Ci)=3.7 1010Bq.3.2.2 dpm,ndisintegrations per minute,used to measurethe quantity of radioactivity.3.2.2.1 DiscussionThe measure dpm is derived fromcounts per minute(cpm)where dpm=cmp-bkgd countingefficiency.There are 2.2 106dpm/Ci.3.2.3 mCi,nmillicurie;1/1000th of a curie(standard unit).3.2.4 Ci,nmicrocurie;1/1000th of a millicurie.3.2.5 MSW,nmunicipal solid waste(organic
