ASTM_D_5209_-_92.pdf

Designation:D 5209 92Standard Test Method forDetermining the Aerobic Biodegradation of Plastic Materialsin the Presence of Municipal Sewage Sludge1This standard is issued under the fixed designation D 5209;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the degreeand rate of aerobic biodegradation of synthetic plastic materials(including formulation additives that may be biodegradable)onexposure to activated-sewage sludge inoculum under labora-tory conditions.1.2 This test method is designed to index plastic materialsthat are more or less biodegradable relative to a standard in anaerobic environment.1.3 This test method is designed to be applicable to allplastic materials that are not inhibitory to the bacteria presentin the activated sewage sludge.1.4 The values stated in SI units are to be regarded as thestandard.1.5 This standard does not purport to address all of thesafety problems,if any,associated 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.Specific hazards aregiven in Section 8.2.Referenced Documents2.1 ASTM Standards:D 618 Practice for Conditioning of Plastics and ElectricalInsulating Materials for Testing2D 883 Terminology Relating to Plastics2D 1193 Specification for Reagent Water3D 1898 Practice for Sampling of Plastics2D 2667 Test Method for Biodegradability of AlkylbenzeneSulfonates4D 3593 Test Method for Molecular Weight Averages andMolecular Weight Distribution of Certain Polymers byLiquid Size-Exclusion Chromatography(Gel PermeationChromatography-GPC)Using Universal Calibration53.Terminology3.1 Definitions:3.1.1 Definitions of terms applicable to this test methodappear in Terminology D 883D 883.4.Summary of Test Method4.1 The test method described consists of selection ofplastic material for the determination of aerobic biodegradabil-ity,obtaining activated sewage sludge from a municipal-wastewater-treatment plant and preparing inoculum,exposingplastic material to the aerated inoculum,measuring carbondioxide evolved as a function of time,soluble organic carbon(SOC)content and residual polymer weight,and assessingdegree of biodegradability.4.2 The percent of theoretical gas production based onmeasured or calculated carbon content is reported with respectto time from which the degree of biodegradability is assessed.5.Significance and Use5.1 The degree and rate of aerobic biodegradability of aplastic material in the environment determines to what extentand in what time period that plastic may be eliminated from theenvironment.With increasing use of plastics,disposal isbecoming a major issue and the results of this test method maypermit an estimation of the degree of biodegradability and overwhat time period plastics will remain in an aerobic environ-ment.This test method determines the degree of aerobicbiodegradation by measuring evolved carbon dioxide,SOC,and residual polymeric material as a function of time,when theplastic is exposed to activated sewage-sludge.5.2 Activated sewage-sludge from a sewage-treatment plantthat treats principally municipal waste is considered an accept-able active aerobic environment available over a wide geo-graphical area in which to test a broad range of plasticmaterials.Because of the enriched environment of activated1This test method is under the jurisdiction ofASTM Committee D-20 on Plasticsand is the direct responsibility of Subcommittee D20.96 on EnvironmentallyDegradable Plastics.Current edition published July 31,1992.Approved September 1992.Originallypublished as D 5209 91.Last previous edition D 5209 91.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 11.01.4Annual Book of ASTM Standards,Vol 15.04.5Annual Book of ASTM Standards,Vol 08.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Please contact ASTM International(www.astm.org)for the latest information.sewage-sludge,the inoculum may be more diverse in compo-sition than a typical aerobic environment that plastics encoun-ter in usual disposal methods.6.Apparatus6.1 Carbon Dioxide Scrubbing Apparatus(See Fig.1)foreach specimen the following is required:6.1.1 A series of twelve 4 L Erlenmeyer flasks(three testmaterials,and four Erlenmeyer flasks per test)requires thefollowing6.1.1.1 Four 1-L plastic bottles,containing 700 mL of 10Nsodium hydroxide(NaOH),6.1.1.2 Two empty 1-L Erlenmeyer flasks,to prevent liquidcarry over,and6.1.1.3 One 1-L Erlenmeyer flask,containing 700 mL of0.025N bariu