ASTM_E_2170_-_01_2008.pdf

Designation:E 2170 01(Reapproved 2008)Standard Test Method forDetermining Anaerobic Biodegradation Potential of OrganicChemicals Under Methanogenic Conditions1This standard is issued under the fixed designation E 2170;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 covers screening procedures for thedetermining the biodegradation potential of organic chemicalsunder methanogenic conditions using an inoculum fromanaerobic sewage treatment.The conditions described in thistest method are not necessarily optimal for biodegradation,since it involves a dilute inoculum and a relatively highconcentration of test chemical.1.2 The test method is applicable to most organic chemicals,assuming that they can be accurately dosed into the testsystems.The test is not applicable to chemicals that areinhibitory at the concentration used in the test or those whosevolatility generates significant head pressure in the test vessels.1.3 This standard does not purport to address all of thesafety concerns,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 hazardstatements are given in Section 8.2.Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 5904 Test Method for Total Carbon,Inorganic Carbon,and Organic Carbon in Water by Ultraviolet,PersulfateOxidation,and Membrane Conductivity Detection3.Terminology3.1 Definitions:3.1.1 biodegradation potentialthe ability of an organicchemical to undergo partial or complete biodegradation underthe conditions of the test.In the context of this test,biodegra-dation is evidenced by the production of methane and carbondioxide,which is measured as an increased pressure in theheadspace and increased dissolved inorganic carbon in themedium.3.1.2 digester sludgesludge which is obtained from ananaerobic reactor used to reduce the solids recovered andproduced during the treatment of wastewater.Such reactors aregenerally operated at 35C with a typical retention time of 25to 30 days.4.Summary of Test Method4.1 The test chemical and an anaerobic digester sludgeinoculum are suspended in a defined anaerobic medium andincubated in a sealed vessel at 35C.The increase in headspacepressure resulting from the production of carbon dioxide andmethane is measured at various time intervals using a pressuremeasuring device.At the termination of the test,the level ofdissolved carbon dioxide is assayed by measuring dissolvedinorganic carbon in the medium.The amount of total gasproduced from the test chemical is determined by comparingtotal gas production in the experimental treatments and theblanks.5.Significance and Use5.1 Biodegradation is an important process for the removalof many chemical substances in anaerobic environments.Inmethanogenic environments,this process involves dissimila-tion to carbon dioxide and methane.5.2 This test method has been developed to screen organicchemicals for anaerobic biodegradation potential under metha-nogenic conditions,where there is no ingress of oxygen.Ahigh-biodegradability result in this test method is good evi-dence that the test substance will be biodegradable in wastetreatment plant anaerobic digesters and in many natural envi-ronments.Conversely,a low-biodegradation result may havecauses other than poor biodegradability of the test substance.Inhibition of the microbial inoculum by the test substance mayhave occurred at the concentrations tested,or conditions in thetest may have been inappropriate for the development of anacclimated microbial population.Toxicity should be suspectedwhen the gas production in the blanks exceeds that in the testvessels.In such cases,further work is needed to assess the1This test method is under the jurisdiction of ASTM Committee E47 onBiological Effects and Environmental Fate and is the direct responsibility ofSubcommittee E47.04 on Environmental Fate and Transport of Biologicals andChemicals.Current edition approved Feb.1,2008.Published March 2008.Originallyapproved in 2001.Last previous edition approved in 2001 as E 217001.2For referenced ASTM standards,visit the ASTM website,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.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.w w w.b a b a k e.n e t 巴巴客免费下载anaerobic biodegradation potential of the chemical.An esti-mate of the expected environmental concentration will help toput any observed toxic effects into perspective.6.Apparatus6.1 Incubator,