1、Designation: D6784 16Standard Test Method forElemental, Oxidized, Particle-Bound and Total Mercury inFlue Gas Generated from Coal-Fired Stationary Sources(Ontario Hydro Method)1This standard is issued under the fixed designation D6784; the number immediately following the designation indicates the y
2、ear 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 applies to the determination ofeleme
3、ntal, oxidized, particle-bound, and total mercury emis-sions from coal-fired stationary sources.1.2 This test method is applicable to elemental, oxidized,particle-bound, and total mercury concentrations ranging fromapproximately 0.5 to 100 g/Nm3.1.3 This test method describes equipment and procedure
4、sfor obtaining samples from effluent ducts and stacks, equip-ment and procedures for laboratory analysis, and proceduresfor calculating results.1.4 This test method is applicable for sampling elemental,oxidized, and particle-bound mercury in flue gases of coal-firedstationary sources. It may not be
5、suitable at all measurementlocations, particularly those with high particulate loadings, asexplained in Section 16.1.5 Method applicability is limited to flue gas streamtemperatures within the thermal stability range of the samplingprobe and filter components.1.6 The values stated in SI units are to
6、 be regarded as thestandard. The values in parentheses are for information only.1.7 This standard requires users to be familiar with EPAstack-gas sampling procedures as stated in EPA Methods 14,Method 5, and Method 17.1.8 The method requires a high level of experience andquality control both in the
7、field testing and analytical proce-dures in order to obtain high quality data.1.9 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 deter
8、mine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3154 Test Method for Average Velocity in a Duct (PitotTube Method)D3685/D3685M Test Methods
9、 for Sampling and Determina-tion of Particulate Matter in Stack GasesD3796 Practice for Calibration of Type S Pitot TubesD4840 Guide for Sample Chain-of-Custody ProceduresD7036 Practice for Competence of Air Emission TestingBodiesE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Ha
10、zard Precision Liquids2.2 Other Standards:3EPAMethod 1 Sample and Velocity Traverses for StationarySourcesEPA Method 2 Determination of Stack Gas Velocity andVolumetric Flow Rate (Type S Pitot Tube)EPA Method 3 Gas Analysis for the Determination of DryMolecular WeightEPA Method 4 Determination of Mo
11、isture Content in StackGasesEPA Method 5 Determination of Particulate Emissions fromStationary SourcesEPA Method 12 Determination of Inorganic Lead Emissionsfrom Stationary SourcesEPA Method 17 Determination of Particulate Emissionsfrom Stationary Sources (In-Stack Filtration Method)EPA Method 29 De
12、termination of Metals Emissions fromStationary Sources1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved March 1, 2016. Published June 2016. Origin
13、allyapproved in 2002. Last previous edition approved in 2008 as D6784 02 (2008).DOI: 10.1520/D6784-16.2For 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
14、Document Summary page onthe ASTM website.3EPA Methods129available from the U.S. Environmental ProtectionAgencys Emission Measurement Technical Information Center or Code of FederalRegulations (40 CFR Part 60, Appendix A), Method 101A in 40 CFR Part 61,Appendix B, Method 301 in 40 CFR 63 Appendix A40
15、 CFR Part 61, Appendix B.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1EPA Method 101A Determination of Particle-Bound andGaseous Mercury Emissions from Sewage Sludge Incin-eratorsEPA Method 301 Field Validation of Pollutant Measure
16、mentMethods from Various Waste MediaEPA SW 846 7470A Mercury in Liquid WasteManualCold Vapor TechniqueEPA Water and Waste 600/4-79-020 Methods for ChemicalAnalysis of Water and Wastes3. Terminology3.1 Definitions other than those given below in 3.2 and 3.3are listed in Terminology D1356.3.2 Definiti
17、ons of Terms Specific to This Standard:3.2.1 elemental mercurymercury in its zero oxidationstate, Hg0.3.2.2 elemental mercury catchmercury collected in theacidified hydrogen peroxide (HNO3H2O2) and potassiumpermanganate (H2SO4KMnO4) impinger solutions employedin this test method. This is gaseous Hg0
18、.3.2.3 front half of the sampling trainall mercury collectedon and upstream of the sample filter.3.2.4 impinger trainsetup including only the impingersand connectors.3.2.5 method detection limitthe minimum concentrationof an analyte, when processed through the complete method,produces a signal with
19、a 99 % probability that is different fromthe blank, based on a standard deviation of greater than sevenreplicate measurements (see Terminology D1356).3.2.6 oxidized mercurymercury in its mercurous or mer-curic oxidation states: Hg22+and Hg2+, respectively.3.2.7 oxidized mercury catchmercury collecte
20、d in theaqueous potassium chloride (KCl) impinger solution employedin this test method. This is gaseous Hg2+.3.2.8 particle-bound mercury catchmercury associatedwith the particulate matter collected in the front half of thesampling train.3.2.9 sample traincomplete setup including nozzle, probe,probe
21、 liner, filter, filter holder, impingers, and connectors.3.2.10 total mercuryall mercury (solid-bound, liquid, orgaseous) however generated or entrained in the flue gas stream(that is, summation of elemental, oxidized, and particle-boundmercury).3.3 Symbols:A = cross-sectional area of stack, m2(ft2)
22、Bws= water vapor in the gas stream, proportion by volumeH = average pressure differential across the orifice meter,kPa (in. H2O)Hgash= concentration of mercury in sample filter ash, g/gHgtp= concentration of particle-bound mercury, g/Nm3Hg0= concentration of elemental mercury, g/Nm3Hg2+= concentrati
23、on of oxidized mercury, g/Nm3IR = instrument reading from mercury analyzer, g/LLp= leakage rate observed during the post test leak check,m3/min (cfm)La= maximum acceptable leakage rateMs= molecular weight of stack gas, wet basis g/g-mole(lb/Lb-mole)Mw= molecular weight of water, 18.0 g/g-mole (18.0
24、lb/Lb-mole)N = Normal conditions, defined as 0C and 101.3 kPa, (Inthe U.S. standard conditions 32F and 1 atmosphere)Pbar= barometric pressure at the sampling site, kPa (in. Hg)Ps= absolute stack gas pressure, kPa (in. Hg)Pstd= standard absolute pressure, 101.3 kPa (29.92 in. Hg)R = ideal gas constan
25、t, 0.008314 kPa-m3/K-g-mole (21.85in. Hg-ft3/R-lb-mole)Tm= absolute average dry gas meter temperature, K (R)Ts= absolute stack temperature, K (R)Tstd= standard absolute temperature, 293 K (528R)VD= total digested volume, mLVm= volume of gas sample as measured by dry gas meter,m3(dscf)Vm(std)= volume
26、 of gas sample measured by the dry gasmeter, corrected to standard conditions, Nm3(dscf)Vw(std)= volume of water vapor in the gas sample, correctedto standard conditions, m3(scf)Wash= total mass of ash on sample filter, gWlc= total weight of liquid collected in impingers and silicagel, g (lb)Y = dry
27、 gas meter calibration factor = total sampling time, min1= sampling time interval, from the beginning of a rununtil the first component change, min4. Summary of Test Method4.1 A sample is withdrawn from the flue gas stream isoki-netically through a probe/filter system, maintained at 120C orthe flue
28、gas temperature, whichever is greater, followed by aseries of impingers in an ice bath. Particle-bound mercury iscollected in the front half of the sampling train. Oxidizedmercury is collected in impingers containing a chilled aqueouspotassium chloride solution. Elemental mercury is collected insubs
29、equent impingers (one impinger containing a chilledaqueous acidic solution of hydrogen peroxide and three im-pingers containing chilled aqueous acidic solutions of potas-sium permanganate). Samples are recovered, digested, andthen analyzed for mercury using cold-vapor atomic absorption(CVAAS) or flu
30、orescence spectroscopy (CVAFS). To achievethe precision specified in this test method, it is necessary thatquality control and quality assurance procedures associatedwith each step of the method be scrupulously performed.Successful performance of the method by air emission testingbodies is best achi
31、eved by following the Practice D7036.5. Significance and Use5.1 The measurement of particle-bound, oxidized,elemental, and total mercury in stationary-source flue gasesprovides data that can be used for emissions assessments andreporting, the certification of continuous mercury monitoringsystems, re
32、gulatory compliance determinations and researchprograms associated with dispersion modeling, depositionD6784 162evaluation, human health and environmental impact assess-ments. Particle-bound, oxidized, and elemental mercury mea-surements before and after control devices may be necessaryfor optimizin
33、g and evaluating the mercury removal efficiencyof emission control technologies.5.2 This test method was developed for the measurement ofmercury in coal-fired power plants and has been extensivelyvalidated for that application. With additional procedures givenin this standard, it is also applicable
34、to sources having a fluegas composition with high levels of hydrochloric acid, and lowlevels of sulfur dioxide.6. Interferences6.1 Chlorine and particulate matter will interfere in speciat-ing flue gas samples for oxidized and elemental mercuryconcentrations. These biases are addressed further in Se
35、ction16 of this test method.7. Apparatus7.1 Sampling TrainSimilar to Test Methods D3685/D3685M, EPA Method 5/EPA Method 17 and EPA Method 29trains, as illustrated in Fig. 1 and Fig. 2.NOTE 1It is recommended that an in-stack filter method (Method 1,Figure 2) be used if possible. The requirement of t
36、he method, that the filterbe maintained at the temperature of the flue gas, is ensured in thisconfiguration. In addition, the instack filter method has the addedadvantage that, only a small portion of the probe/nozzle collects ash thatneeds to be brushed onto the filter. Method 5 procedures must be
37、usedwhen the temperature of the flue gas is below the water dew point (wetstack) In this case an out-of-stack filter must be used and maintained at atemperature of 120C.NOTE 2If sampling is conducted in a wet stack where water dropletsare present, and the nozzle is positioned into the flow, water dr
38、oplets willbe collected and mercury contained in the droplets will be measured.When water droplets are present, the isokinetic sampling rate and percentisokinetic must be calculated accordingly.7.1.1 Probe Nozzle (Probe Tip)Glass nozzles are requiredunless alternate nozzles are constructed of materi
39、als that arefree from contamination and will not interact with the sample.Probe fittings constructed of polytetrafluoroethylene (PTFE),polypropylene, etc., are required instead of metal fittings toprevent contamination.7.1.2 Probe LinerIf the sample train is to be in EPAMethod 5 configuration (out-o
40、f-stack filtration), the probe linermust be constructed of quartz or borosilicate glass. If an EPAMethod 17 (in-stack filtration) sampling configuration is used,the probe/probe liner may be constructed of borosilicate glass,quartz or, depending on the flue gas temperature, PTFE.7.1.3 Pitot Tube, Typ
41、e S pitot tube. Refer to Section 2.2 ofEPA Method 2 for a description.7.1.4 Differential Pressure Gages, inclined manometers orequivalent devices. Refer to Section 2.1 of EPA Method 2 fora description.7.1.5 Filter Holder, constructed of borosilicate glass orPTFE-coated stainless steel with a PTFE fi
42、lter support or othernonmetallic, non-contaminating support. Do not use a glass fritor stainless steel wire screen.Asilicone rubber or PTFE gasket,designed to provide a positive seal against leakage fromoutside or around the filter, may be used.7.1.6 Connecting Umbilical Tube, heated PTFE tubing. Th
43、istube must be heated to a minimum of 120C to help preventwater and acid condensation. (The umbilical tube is defined asany tubing longer than 0.5 m that connects the filter holder tothe impinger train).7.1.7 Probe and Filter Heating System:7.1.7.1 EPA Method 5 ConfigurationFor EPA Method 5configura
44、tion, the temperature of the flue gas, sample probe,and the exit of the sample filter must be monitored usingtemperature sensors capable of measuring temperature towithin 3C (5.4F). The heating system must be capable ofmaintaining the sample gas temperature of the probe and exitof the sample filter
45、to within 615C (627F) of the flue gastemperature. Regardless of the flue gas temperature, to preventwater and acid condensation, the probe temperature, samplefilter exit gas temperature, or the temperature of the connectingumbilical cord shall at no time be less than 120C.FIG. 1 Schematic of Mercury
46、-Sampling Train in the Method 5 ConfigurationD6784 1637.1.7.2 EPA Method 17 ConfigurationFor EPAMethod 17configuration, the sample filter is located in the duct and,therefore, naturally maintained at the flue gas temperature. Theheating system is only required to maintain the probe andconnecting umb
47、ilical cord to at least 120C. If the flue gastemperature is less than 120C, then EPA Method 5 configu-ration must be used.7.1.8 Condensing/Absorbing System, consists of eight im-pingers immersed in an ice bath and connected in series withleak-free ground glass fittings or other non-contaminatingleak
48、-free fittings. (At no time is silicon grease or other greasesto be used for this test method). The first, second, fourth, fifth,sixth, and eighth impingers are of the Greenburg-Smith designmodified by replacing the standard tip with a 1.3-cm (0.5-in.)-ID straight glass tube extending to about 1.3 c
49、m (0.5 in.)from the bottom of the flask. The third and seventh impingersare also Greenburg-Smith design, but with the standard tipincluding the glass impinging plate. The first, second, and thirdimpingers contain aqueous 1 N potassium chloride (KCl)solution. The fourth impinger contains an aqueous solution of5%VV nitric acid (HNO3) and 10 %VV hydrogen peroxide(H2O2). The fifth, sixth, and seventh impingers contain anaqueous solution of 4 %WV potassium permanganate (KMnO4)and 10 %VV sulfuric acid (H2SO4). The last impinger contain
