1、Designation: D 6784 02 (Reapproved 2008)Standard 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 D 6784; the number immediately following the designa
2、tion 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 method applies to the determ
3、ination of elemental,oxidized, particle-bound, and total mercury emissions fromcoal-fired stationary sources.1.2 This method is applicable to elemental, oxidized,particle-bound, and total mercury concentrations ranging fromapproximately 0.5 to 100 g/Nm3.1.3 This method describes equipment and proced
4、ures forobtaining samples from effluent ducts and stacks, equipmentand procedures for laboratory analysis, and procedures forcalculating results.1.4 This method is applicable for sampling elemental,oxidized, and particle-bound mercury in flue gases of coal-firedstationary sources. It may not be suit
5、able 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 be
6、regarded as thestandard. The values in parentheses are for information only.1.7 This standard assumes users are familiar with EPAstack-gas sampling procedures as stated in EPA Methods 14,Method 5, and Method 17.1.8 This standard does not purport to address all of thesafety concerns, if any, associat
7、ed 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.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1356 Terminology Rela
8、ting to Sampling and Analysis ofAtmospheresD 2986 Practice for Evaluation of Air Assay Media by theMonodisperse DOP (Dioctyl Phthalate) Smoke Test3D 3154 Test Method for Average Velocity in a Duct (PitotTube Method)D 3685/D 3685M Test Methods for Sampling and Determi-nation of Particulate Matter in
9、Stack GasesE 1 Specification for ASTM Liquid-in-Glass Thermometers2.2 Other Standards:4EPA Method 1 Sample and Velocity Traverses for Station-ary SourcesEPA Method 2 Determination of Stack Gas Velocity andVolumetric Flow Rate (Type S Pitot Tube)EPA Method 3 Gas Analysis for the Determination of DryM
10、olecular WeightEPA Method 4 Determination of Moisture Content in StackGasesEPAMethod 5 Determination of Particulate Emissions fromStationary SourcesEPAMethod 12 Determination of Inorganic Lead Emissionsfrom Stationary SourcesEPA Method 17 Determination of Particulate Emissionsfrom Stationary Sources
11、 (In-Stack Filtration Method)EPA Method 29 Determination of Metals Emissions fromStationary SourcesEPA Method 101A Determination of Particle-Bound andGaseous Mercury Emissions from Sewage Sludge Incin-eratorsEPAMethod 301 FieldValidation of Pollutant MeasurementMethods from Various Waste MediaEPA SW
12、 846 7470A Mercury in Liquid WasteManualCold Vapor TechniqueEPA Water and Waste 600/4-79-020 Methods for ChemicalAnalysis of Water and Wastes1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres a
13、nd Source Emissions.Current edition approved April 1, 2008. Published July 2008. Originallyapproved in 2002. Last previous edition approved in 2002 as D 6784 - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、 of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from the U.S. Environmental Protection Agencys Emission Mea-surement Technical Information Center or Code of Federal Regulations (40 CFRPart 60, Appendix A or 40 CFR Part 61, A
15、ppendix B).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions other than those given below in 3.2 and 3.3are listed in Terminology D 1356.3.2 Definitions of Terms Specific to This Standard:3.2.1 elemental m
16、ercurymercury in its zero oxidationstate, Hg0.3.2.2 elemental mercury catchmercury collected in theacidified hydrogen peroxide (HNO3H2O2) and potassiumpermanganate (H2SO4KMnO4) impinger solutions employedin this method. This is gaseous Hg0.3.2.3 front half of the sampling trainall mercury collectedo
17、n and upstream of the sample filter.3.2.4 impinger trainsetup including only the impingersand connectors.3.2.5 oxidized mercurymercury in its mercurous or mer-curic oxidation states: Hg22+and Hg2+, respectively.3.2.6 oxidized mercury catchmercury collected in theaqueous potassium chloride (KCl) impi
18、nger solution employedin this method. This is gaseous Hg2+.3.2.7 particle-bound mercury catchmercury associatedwith the particulate matter collected in the front half of thesampling train.3.2.8 sample traincomplete setup including nozzle,probe, probe liner, filter, filter holder, impingers, and conn
19、ec-tors.3.2.9 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)Bws= water vapor in the gas stream, proportion by
20、volumeDH = 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+= concentration of oxidized mercury, g/Nm3IR = instrument read
21、ing 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 lb/Lb-mole)N = Normal conditions, defined as 0C a
22、nd 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 constant, 0.008314 kPa-m3/K-g-mole (21.85in. Hg-ft3/R-lb
23、-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 of gas sample measured by the dry gasmeter, corr
24、ected 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 gas meter calibration factoru = total sampling t
25、ime, minu1= 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 gas temperature, whichever is greater, followed
26、 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 insubsequent impingers (one impinger containing a chi
27、lledaqueous 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 fluorescence spectroscopy (CVAFS).5. Significance
28、and Use5.1 The measurement of particle-bound, oxidized, elemen-tal, and total mercury in stationary-source flue gases providesdata that can be used for dispersion modeling, depositionevaluation, human health and environmental impact assess-ments, emission reporting, compliance determinations, etc.Pa
29、rticle-bound, oxidized, and elemental mercury measure-ments before and after control devices may be necessary foroptimizing and evaluating the mercury removal efficiency ofemission control technologies.6. Interferences6.1 There are no known interferences, but certain biasesmay be encountered (see Se
30、ction 16).7. Apparatus7.1 Sampling TrainSimilar to Test Methods D 3685, EPAMethod 5/EPA Method 17 and EPA Method 29 trains, asillustrated in Fig. 1.7.1.1 Probe Nozzle (Probe Tip)Glass nozzles are requiredunless alternate nozzles are constructed of materials that arefree from contamination and will n
31、ot 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-of-stack filtration), the probe linermust be co
32、nstructed of quartz or borosilicate glass. If an EPAMethod 17 (in-stack filtration) sampling configuration is used,D 6784 02 (2008)2the probe/probe liner may be constructed of borosilicate glass,quartz or, depending on the flue gas temperature, PTFE.7.1.3 Pitot Tube, Type S pitot tube. Refer to Sect
33、ion 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 filter support or othernonmetal
34、lic, 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. Thistube must be heated to a mi
35、nimum 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 5configuration, the temperature of the
36、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 to within 615C (627F) of the
37、flue gastemperature. Regardless of the flue gas temperature, to preventwater and acid condensation, at no time must the probetemperature, sample filter exit gas temperature, or the tempera-ture of the connecting umbilical cord be less than 120C.7.1.7.2 EPA Method 17 ConfigurationFor EPAMethod 17conf
38、iguration, 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 umbilical cord to at least 120C. If the flue gastemperature is less than 120C, then EPA Method 5 configu-ration
39、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-free fittings. (At no time is silicon grease or other greasesto be used for this method). The first, second,
40、 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 cm (0.5 in.)from the bottom of the flask. The third and seventh impingersare also Greenburg-Smith design, but with
41、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%V/Vnitric acid (HNO3) and 10 %V/Vhydrogen peroxide(H2O2). The fifth, sixth, and seventh impingers cont
42、ain anaqueous solution of 4 %W/Vpotassium permanganate(KMnO4) and 10 %V/Vsulfuric acid (H2SO4). The last im-pinger contains silica gel or an equivalent desiccant. Refer toNote 1.NOTE 1When flue gas streams are sampled with high moisturecontent (20 %), additional steps must be taken to eliminate carr
43、yover ofimpinger contents from one sample type to the next. These steps mustinclude use of oversized impinger(s) or use of an empty impinger betweenthe KCl and HNO3H2O2. If a dry impinger is used, it must be rinsed asdiscussed in 13.2 of this method and the rinse added to the precedingimpinger.7.1.9
44、 Metering System, vacuum gage, leak-free pump, ther-mometers capable of measuring temperature to within 3C(5.4F), and a dry gas meter or controlled orifice capable ofmeasuring volume to within 2 %.7.1.10 Barometer, capable of measuring atmospheric pres-sure to within 0.33 kPa (0.1 in. Hg). In many c
45、ases, thebarometric reading may be obtained from a nearby NationalWeather Service station, in which case, the station value(which is the absolute barometric pressure) shall be requested.An adjustment for elevation differences between the weatherstation and sampling point shall be applied at a rate o
46、f negativeFIG. 1 Schematic of Mercury-Sampling Train in the Method 5 ConfigurationD 6784 02 (2008)30.33 kPa (0.1 in. Hg) per 30 m (100 ft) elevation increase orvice versa for elevation decrease.7.1.11 Gas Density Determination Equipment, temperaturesensor and pressure gage, as described in Section 2
47、.3 and 2.4 ofEPA Method 2. The temperature sensor shall, preferably, bepermanently attached to the pitot tube or sampling probe in afixed configuration, such that the sensor tip extends beyond theleading edge of the probe sheath and does not touch any metal.Alternative temperature sensor configurati
48、ons are described inSection 2.1.10 of EPA Method 5. If necessary, a gas analyzercan be used to determine dry molecule weight of the gas (referto EPA Method 3).7.2 Digestion Apparatus:7.2.1 Dry Block Heater or Hot Water Bath, a heater capableof maintaining a temperature of 95C is required for digesti
49、onof samples, similar to that described in EPA SW 846 Method7470A.7.2.2 Ice Bath.7.2.3 Digestion FlasksUse 50- to 70-mL glass tubes orflasks with screw caps that will fit a dry block heater. For awater bath, 300-mLbiological oxygen demand glass bottles forSW 846 Method 7470A are to be used. In addition, borosilicateglass test tubes, 35- to 50-mL volume, with rack are needed.7.2.4 Microwave or Convection Oven and PTFE DigestionVessels, 120 mL, or equivalent digestion vessels with capsequipped with pressure relief valves for the dissolutio
