ASTM_D_6776_-_02.pdf

Designation:D 6776 02Standard Test Method forDetermining Anaerobic Biodegradability of RadiolabeledPlastic Materials in a Laboratory-Scale Simulated LandfillEnvironment1This standard is issued under the fixed designation D 6776;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is designed to measure the anaerobicbiodegradability of a material under conditions that simulateaccelerated decomposition in a municipal solid waste(MSW)landfill.The test method requires the use of a14C-labeledmaterial so that biodegradability can be determined by moni-toring for methane(14CH4)and gaseous and aqueous carbondioxide(14CO2(g)and14CO2(aq),which are the terminal end-products of methanogenic decomposition.Methanogenic con-ditions typically control decomposition in landfills.NOTE1A more complete description of this decomposition is foundin Reference(3).21.2 This method could be applied to landfills that containmaterials other than MSW.14C-Radiolabeled material will beadded to compost such that between 25 ci and 75 ci activityper 2 litres of test refuse results.NOTE2Adding more radiolabel is desirable because,if the materialbiodegrades,there will be little residual radiolabel left at the end of thedecomposition experiment,which is when the refuse is removed from areactor and analyzed for residual radiolabel to perform a mass balance.Inaddition,if insufficient radiolabel is added,then CH4and CO2(g)produc-tion from the added refuse will dilute the14CH4and14CO2(g)fromdecomposition of the test material,and the labeled gases may not bedetected in the reactor offgas.1.3 This measure of anaerobic biodegradability in the labo-ratory represents what will ultimately occur in a landfill over along period.The test conditions specified here are designed toaccelerate refuse decomposition such that the entire decompo-sition cycle can be completed in six months.NOTE3This cycle may require decades in a landfill depending uponthe actual environmental conditions(moisture content,pH,temperature).1.4 The measured biodegradability obtained here is com-pared to the biodegradability of both pure and lignifiedcellulose,which are chemically similar to office paper andnewsprint,both of which are routinely buried in landfills.NOTE4The degradability of the referenced compounds is describedin References(2)and(5).At this time,there is no standard concerning the extent towhich a compound must biodegrade under the test conditionsdescribed here to be considered biodegradable.Thus,this testis most appropriately used to measure biodegradability relativeto pure and lignified cellulose.1.5 The safety problems associated with refuse and radio-activity are not addressed in this standard.It is the responsi-bility of the user 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.NOTE5There are no corresponding ISO standards.2.Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics3E 170 Terminology Relating to Radiation Measurementsand Dosimetry43.Terminology3.1 Terminology used in this Standard are defined in Ter-minology D 883 or Terminology E 170.3.2 refuse,nwaste material for anaerobic decomposition.May be municipal or agricultural in source but not meant toinclude sludge from water treatment or sewage treatmentfacilities.1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.96 on EnvironmentallyDegradable Plastics.Current edition approved March 10,2002.Published May 2002.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3Annual Book of ASTM Standards,Vol 08.01.4Annual Book of ASTM Standards,Vol 12.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.3 seed,nrefuse material from an active anaerobic de-composition producing methane;which is used for inoculum ofrefuse material to undergo anaerobic decomposition.4.Summary of Test Method4.1 A14C-labeled material is added to a mixture of fresh anddecomposed refuse in a laboratory reactor.The old refuseserves as a seed to rapidly initiate methanogenesis.The volumeof gas produced and the concentrations of14CH4and14CO2(g)are monitored.In addition,the reactor leachate is monitoredfor14C-organics and14CO2(aq).At the conclusion of the refusedecomposition cycle,which typically requires 6 to 9 months,the refuse is removed from the reactor,dried,ground to a finepowder and analyzed for residual14C by combustion.A massbalance on the added14C is then conducted.5.Significance and Use5.1 This method can