ASTM_D_2010_-_D_2010M_-_98_2010.pdf

Designation:D2010/D2010M98(Reapproved 2010)Standard Test Methods forEvaluation of Total Sulfation Activity in the Atmosphere bythe Lead Dioxide Technique1This standard is issued under the fixed designation D2010/D2010M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods describe the evaluation of the totalsulfation activity in the atmosphere.Because of its oxidizingpower,lead dioxide(PbO2)converts not only sulfur dioxide(SO2),but other compounds,such as mercaptans and hydrogensulfide,into sulfate.It fixes sulfur trioxide and sulfuric acidmist present in the atmosphere(see Note 1).1.2 Test Method A describes the use of a PbO2candle,andTest Method B describes that of a PbO2sulfation plate.21.3 These test methods provide a weighted average effectiveSO2level for a 30-day interval.1.4 The results of these test methods correlate approxi-mately with volumetric SO2concentrations,although thepresence of dew or condensed moisture tends to enhance thecapture of SO2onto the candle or plate.1.5 The values stated in SI units shall be regarded as thestandard.The values given in brackets are for information onlyand may be approximate.NOTE1It has been shown that the rate constant of the chemicalreaction between SO2and PbO2is independent of the concentration ofSO2up to levels of 1000 ppm(v),if 15%or less of the PbO2has beenreduced(1).315%of the PbO2is equivalent to 11 to 12 mg of SO2/cm2per day.1.6 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.For specificprecautionary statements,see Section 8.2.Referenced Documents2.1 ASTM Standards:4D516 Test Method for Sulfate Ion in WaterD1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphereG91 Practice for Monitoring Atmospheric SO2DepositionRate for Atmospheric Corrosivity Evaluation3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,refer to Terminology D1356.3.2 Definitions of Terms Specific to This Standard:3.2.1 sulfationthe process by which sulfur-containingcompounds are oxidized by the action of PbO2.3.2.2 sulfationactivitythecapturerateofsulfur-containing compounds as they are oxidized by PbO2under theconditions of these test methods.4.Summary of Test Methods4.1 Test Method AInert cylinders are coated with PbO2paste and exposed to the atmosphere for an extended period oftime,usually one month.Sulfur oxides react chemically withthe paste,forming lead sulfate(PbSO4)(1-5).4.2 Test Method BSulfation plates consisting of a PbO2paste in an inverted dish are likewise exposed to the atmo-sphere(6).4.3 Test Methods A and BThe cylinders or plates arereturned to a laboratory after the sampling period;the paste isremoved and suspended in hot sodium carbonate(Na2CO3)solution to dissolve the PbSO4and convert the sulfate tosoluble sodium sulfate(Na2SO4).The Na2SO4solution is1These test methods are under the jurisdiction of ASTM Committee D22 on AirQuality and are the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Oct.1,2010.Published March 2011.Originallyapproved in 1962.Last previous edition approved in 2004 as D2010/D2010M 98(2004).DOI:10.1520/D2010_D2010M-98R10.2Test Method B has been adapted from Test Method G91,which is under thejurisdiction ofASTM Committee D22 on Air Quality and is the direct responsibilityof Subcommittee D22.03 on Ambient Atmospheres and Source Emissions.3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.4For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 separated from the PbO2slurry by filtration.The sulfate isdetermined by precipitation with barium chloride(BaCl2)(7).4.4 The chemistry of the process is illustrated,for the caseof SO2,in the following reactions:PbO21SO2PbSO4PbSO41N a2CO3Na2SO41PbCO3Na2SO41BaCl2BaSO412 NaCl5.Significance and Use5.1 Sulfur oxide gases are produced during the combustionof materials containing sulfur.These gases are precursors ofatmospheric sulfuric acid,which has been shown to be injuri-ous to living creatures and plants,as well