ASTM_D_2667_-_95_2001.pdf

Designation:D 2667 95(Reapproved 2001)Standard Test Method forBiodegradability of Alkylbenzene Sulfonates1This standard is issued under the fixed designation D 2667;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 method2covers the determination of the degreeof biodegradability of alkylbenzene sulfonates.It serves as anindex of the suitability of the sulfonate for general use as asurfactant.1.2 In general,this test method distinguishes between sul-fonates in which the alkyl side chains are linear and those inwhich they are branched,since the former are more readilybiodegradable.If the alkylbenzene sulfonate in fully formu-lated products is to be examined,it must be extracted using themethod noted in Annex A1.(See Appendix X1 for data.)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.Material SafetyData Sheets are available for reagents and materials.Reviewthem for hazards prior to usage.2.Referenced Documents2.1 ASTM Standards:D 1293 Test Methods for pH of Water3D 2330 Test Method for Methylene Blue Active Sub-stances4E 1625 Test Method for Determining Biodegradability ofOrganic Chemicals in Semi-Continuous Activated Sludge(SCAS)53.Summary of Test Method3.1 The sample is first subjected to a presumptive test basedon shake culture.When necessary,the sample may be sub-jected to a confirming test based on semicontinuous treatmentwith activated sludge.3.2 In the presumptive test,microorganisms are inoculatedinto a flask that contains a chemically defined microbial growthmedium(basal medium)and the surfactant to be tested.Aeration is accomplished by continuous shaking of the flask.Following two adaptive transfers,biodegradation is determinedby measuring the reduction in surfactant content during the testperiod.3.3 In the confirming test,activated sludge obtained from asewage treatment plant is used.The sludge,the surfactant to betested,and a synthetic sewage used as an energy source for thesludge microorganisms are all placed in a specially designedaeration chamber.The mixture is aerated for 23 h,allowed tosettle,and the supernatant material removed.The sludgeremaining in the aeration chamber is then brought back tovolume with fresh surfactant and synthetic sewage and thecycle repeated.Biodegradation is determined by the reductionin surfactant content during each cycle.4.Significance and Use4.1 This test method is designed to determine whether thesulfonate tested will be removed sufficiently by usual methodsof sewage treatment for the effluent to be safely discharged tothe environment without further treatment.4.2 If the surfactant reduction in the presumptive test equalsor exceeds 90%,the material is considered to be adequatelybiodegradable without further testing.4.3 If the surfactant reduction in the presumptive test isbetween 80 and 90%,the material should be subjected to theconfirming test.4.4 If the surfactant reduction in the presumptive test isbelow 80%,the material is considered inadequately biode-gradable.4.5 If it is necessary to run the confirming test,the surfactantreduction in this test must be at least 90%for the material tobe considered adequately biodegradable.1This test method is under the jurisdiction of ASTM Committee E-47 onBiological Effects and Environmental Fate and is the direct responsibility ofSubcommittee E47.04 on Environmental Fate of Chemical Substances.Current edition approved Oct 10,1995.Published December 1995.Originallypublished as D 2667 67 T.Last previous edition D 2667 89.2This test method is based on“AProcedure and Standards for the Determinationof the Biodegradability of Alkyl Benzene Sulfonate and Linear Alkylate Sulfonate”by the Committee on Biodegradation Test Methods of the Soap and the DetergentAssociation,Journal of the Americal Oil Chemists Society,Vol 42,1965,p.986.3Annual Book of ASTM Standards,Vol 11.01.4Annual Book of ASTM Standards,Vol 11.02.5Annual Book of ASTM Standards,Vol 11.05.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.4.6 An example of data from both the presumptive andconfirming test can be found in Appendix X4.PRESUMPTIVE TEST(SHAKE CULTURE)5.Apparatus5.1 Shaking MachineA reciprocating shaker operating atabout 128 strokes of 51 to 101.6 mm(2 to 4 in.)/min or agyrator shaker operating at 225 to 250 r/min with an amplitudeof 25 to 51 mm(1 to 2 in.)should be used.(Other shakers maybe used if equivalent aeration can be demonstrated.)6.Reagents and Materials6.1 Purity of WaterEither distilled or deioniz