ASTM D4839-2003 Standard Test Method for Total Carbon and Organic Carbon in Water by Ultraviolet or Persulfate Oxidation or Both and Infrared Detection《用紫外线法或过硫酸盐氧化法或同时使用两种方法以及红外线法.pdf

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1、Designation: D 4839 03Standard Test Method forTotal Carbon and Organic Carbon in Water by Ultraviolet, orPersulfate Oxidation, or Both, and Infrared Detection1This standard is issued under the fixed designation D 4839; the number immediately following the designation indicates the year oforiginal ad

2、option 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 the determination of totalcarbon (TC), inorga

3、nic carbon (IC), and total organic carbon(TOC) in water, wastewater, and seawater in the range from 0.1mg/L to 4000 mg/L of carbon.1.2 This test method was used successfully with reagentwater spiked with sodium carbonate, acetic acid, and pyridine.It is the users responsibility to ensure the validit

4、y of this testmethod for waters of untested matrices.1.3 This test method is applicable only to carbonaceousmatter in the sample that can be introduced into the reactionzone. The syringe needle or injector opening size generallylimit the maximum size of particles that can be so introduced.1.4 In add

5、ition to laboratory analyses, this test method maybe applied to stream monitoring.1.5 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 d

6、etermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 1129 Terminology Relating to Water2D 1192 Specification for Equipment for Sampling Waterand Steam2D 1193 Specification for Reagent Water2D 2777 Practice for Determination of Precision and B

7、ias ofApplicable Methods of Committee D-19 on Water2D 3370 Practices for Sampling Water from Closed Con-duits2D 4129 Test Method for Total and Organic Carbon in Waterby Oxidation and Coulometric Detection3D 5847 Practice for the Writing Quality Control Specifica-tions for Standard Test Methods for W

8、ater Analysis23. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminology D 1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 inorganic carbon (IC)carbon in the form of carbondioxide, carbonate ion, or bicarbonate ion.3.2.2 total organic car

9、bon (TOC)carbon in the form oforganic compounds.3.2.3 total carbon (TC)the sum of IC and TOC.3.2.4 refractory materialthat which cannot be oxidizedcompletely under the test method conditions.4. Summary of Test Method4.1 FundamentalsCarbon can occur in water as an inor-ganic and organic compound. Thi

10、s test method can be used tomake independent measurements of IC, TOC, and TC, and canalso determine IC by the difference of TC and TOC, and TOCas the difference of TC and IC.4.2 The essentials of this test method are: (a) removal of IC,if desired, by acidification of the sample and sparging bycarbon

11、-free gas; (b) conversion of remaining carbon to CO2byaction of persulfate, aided either by elevated temperature orultraviolet (UV) radiation; (c) detection of CO2that is sweptout of the reactor by a gas stream; and (d) conversion ofdetector signal to a display of carbon concentration in mg/L. Adiag

12、ram of suitable apparatus is given in Fig. 1.5. Significance and Use5.1 This test method is used for determination of the carboncontent of water from a variety of natural, domestic, andindustrial sources. In its most common form, this test methodis used to measure organic carbon as a means of monito

13、ringorganic pollutants in industrial wastewater. These measure-ments are also used in monitoring waste treatment processes.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in

14、 Water.Current edition approved Jan. 10, 2003. Published January 2003. Originallyapproved in 1988. Last previous edition approved in 1994 as D 4839 94.2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 11.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700

15、, West Conshohocken, PA 19428-2959, United States.5.2 The relationship of TOC to other water quality param-eters such as chemical oxygen demand (COD) and total oxygendemand (TOD) is described in the literature.46. Interferences and Limitations6.1 The oxidation of dissolved carbon to CO2is broughtabo

16、ut at relatively low temperatures by the chemical action ofreactive species produced by hot or UV-irradiated persulfateions. Even if oxygen is used as the sparging gas, it makes amuch lower contribution to oxidation than in high-temperature(combustive) systems. Not all suspended or refractory materi

17、almay be oxidized under these conditions; analysts should takesteps to determine what recovery is being obtained. This maybe done by several methods: (a) by monitoring reactionprogress to verify that oxidation has been completed; (b)byrerunning the sample under more vigorous reaction conditions;(c)

18、by analyzing the sample by an alternative method, such asTest Method D 4129, known to result in full recovery; or (d)byspiking samples with known refractories and determiningrecovery.6.2 Chloride ion tends to interfere with oxidative reactionmechanisms in this test method, prolonging oxidation times

19、and sometimes preventing full recovery. Follow manufactur-ers instructions for dealing with this problem. See AppendixX1 for supporting data.6.3 Homogenizing or sparging of a sample, or both, maycause loss of purgeable organic compounds, thus yielding avalue lower than the true TOC level. (For this

20、reason, suchmeasurements are sometimes known as nonpurgeable organiccarbon (NPOC). The extent and significance of such lossesmust be evaluated on an individual basis. This may be done bycomparing the TOC by difference (TC-IC) with the direct TOCfigure, that is, that obtained from a sparged sample. T

21、hedifference, if any, between these TOC figures representspurgeable organic carbon (POC) lost during sparging. Alterna-tively, direct measurement of POC can be made duringsparging, using optional capabilities of the analyzer.6.4 Note that error will be introduced when the method ofdifference is used

22、 to derive a relatively small level from twolarge levels. For example, a ground water high in IC and lowin TOC will give a poorer TOC value as (TC-IC) than by directmeasurement.7. Apparatus7.1 Homogenizing ApparatusA household blender is gen-erally satisfactory for homogenizing immiscible phases inw

23、ater.7.2 Sampling DevicesMicrolitre-to-millilitre syringes aretypically required for this test method. Alternatives includemanually operated or automatically operated sampling valves.Sampling devices with inside diameters as small as 0.15 mmmay be used with samples containing little or no particulat

24、ematter. Larger inside dimensions such as 0.4 mm will berequired for samples with particulate matter.NOTE 1See 6.1 concerning oxidation of particulate matter.7.3 Apparatus for Carbon DeterminationThis instrumentconsists of reagent and sample introduction mechanism, agas-sparged reaction vessel, a ga

25、s demister or dryer, or both, anoptional CO2trap, a CO2-specific infrared detector, a controlsystem, and a display. Fig. 1 shows a diagram of such anarrangement.7.3.1 Sparging requires an inert vessel with a capacity of atleast double the sample size with provision for sparging with50 to 100 mL/min

26、of carbon free gas. This procedure willremove essentially all IC in 2 to 10 min, depending on design.7.3.2 OxidationThe reaction assembly contains reagentand sample introduction devices, and a reactor vessel withsparging flow of carbon-free gas. The vessel may be heated byan external source, and may

27、 contain a UV lamp. The reactionvessel and sparging vessel (see 6.3) may be combined.7.3.3 Gas ConditioningThe gas passing from the reactoris dried, and the CO2produced is either trapped and laterreleased to the detector, or routed directly to the detectorthrough a chlorine-removing scrubber.7.3.4 D

28、etectorThe CO2in the gas stream is detected by aCO2-specific nondispersive infrared (NDIR) detector.7.3.5 Presentation of ResultsThe NDIR detector output isrelated to stored calibration data and then displayed as milli-grams of carbon per litre.8. Reagents and Materials8.1 Purity of ReagentsReagent

29、grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,5where such specifications are available. Other grades may beused, provided it is first ascerta

30、ined that the reagent is ofsufficient purity to permit its use without lessening the accu-racy of the determination.4Handbook for Monitoring Industrial Wastewater, Section 5.3, U.S. Environ-ment Protection Agency, August 1973, pp. 512.5Reagent Chemicals, American Chemical Society Specifications, Ame

31、ricanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (U

32、SPC), Rockville,MD.FIG. 1 Diagram of ApparatusD48390328.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193, Type I or Type II. The indicatedspecification does not actually specify inorganic carbon ororganic carb

33、on levels. These levels can affect the results of thistest method, especially at progressively lower levels of thecarbon content in the samples to be measured. Where inorganiccarbon in reagent water is significant, CO2-free water may beprepared from reagent water by acidifying to pH 2, thensparging

34、with fritted-glass sparger using CO2-free gas (timewill depend on volume and gas flow rate, and should bedetermined by test). Alternatively, if the carbon contribution ofthe reagent water is known accurately, its effect may beallowed for in preparation of standards and other solutions.CO2-free water

35、 should be protected from atmospheric contami-nation. Glass containers are required for storage of water andstandard solutions.8.3 AcidVarious concentrated acids may be used foracidification of samples and of the oxidizing reagent. Acidssuch as phosphoric (sp gr 1.69), nitric (sp gr 1.42), or sulfur

36、ic(sp gr 1.84) are suitable for most applications. Sulfuric acidshould be used in the form of a 1 + 1 dilution, for safetyreasons. Hydrochloric acid is not recommended.8.4 Organic Carbon, Standard Solution (2000 mg/L)Choose a water-soluble, stable reagent grade compound, suchas benzoic acid or anhyd

37、rous potassium hydrogen phthalate(KHC8H4O4). Calculate the weight of compound required tomake 1 L of organic carbon standard solution; for example,KHC8H4O4= 0.471 g of carbon per gram, so one litre of 2 g/Lof standard requires 2/0.471, or 4.25, grams of KHP. Dissolvethe required amount of standard i

38、n some CO2-free water in a1-L volumetric flask, add 1 mL of acid, and dilute to volume.This stock solution, or dilutions of it, may be used to calibrateand test performance of the carbon analyzer.8.5 Persulfate SolutionPrepare by dissolving the appro-priate weight of potassium or sodium persulfate i

39、n 1 Lof water,to produce the concentration specified by the instrumentmanufacturer. If specified, add 1 mL of phosphoric acid (sp gr1.69) and mix well. Store in a cool, dark place. Recipes for thisreagent solution may be modified by manufacturers to meet theneeds of specific applications, for exampl

40、e, high chloridesamples.8.6 Gas SupplyA gas free of CO2and of organic matter isrequired. Use a purity as specified by the equipment manufac-turer. The use of oxygen is preferred for the UV-persulfatemethod, and nitrogen or helium is preferred if a CO2trap isused between reactor and detector.9. Sampl

41、ing and Sample Preservation9.1 Collect the sample in accordance with SpecificationD 1192 and Practice D 3370.9.2 To preserve samples for this analysis, store samples inglass at 4C. To aid preservation, acidify the samples to a pHof 2. It should be noted that acidification will enhance loss ofinorgan

42、ic carbon. If the purgeable organic fraction is important,fill the sample bottles to overflowing with a minimum ofturbulence and cap them using a fluoropolymer-lined cap,without headspace.9.3 For monitoring of waters containing solids or immis-cible liquids that are to be injected into the reaction

43、zone, usea mechanical homogenizer or ultrasonic disintegrator. Filteringor screening may be necessary after homogenization to rejectparticle sizes that are too large for injection. Volatile organicsmay be lost. See 6.3.9.4 For wastewater streams where carbon concentrations aregreater than the desire

44、d range of instrument operation, dilutethe samples as necessary.10. Instrument Operation10.1 Follow the manufacturers instructions for instrumentwarm-up, gas flows, and liquid flows.11. Calibration11.1 Use the stock solution of 2000 mg/L of carbon, andvarious dilutions of it, for calibration.NOTE 2D

45、ilutions should be made with CO2-free water (see 8.2).11.2 Calibration protocols may vary with equipment manu-facturers. However, in general, calibrate the instrument inaccordance with the manufacturers instructions, and usestandards to verify such calibration in the specific range ofinterest for ac

46、tual measurements. Plots of standard concentra-tion versus instrument reading may be used for calibration or toverify linearity of response.11.3 Establish instrument blank according to the manufac-turers instructions.12. Procedure12.1 Mix or blend each sample thoroughly and carry out anynecessary di

47、lution to bring the carbon content within range ofthe instrument.12.2 If inorganic carbon is to be measured directly, injectthe sample into the analyzer under appropriate conditions.12.3 If inorganic carbon is to be removed by sparging priorto sample introduction, acidify to approximately pH 2 withc

48、oncentrated acid (if not already done) and sparge with anappropriate flow of gas. Samples with high alkali content orbuffer capacity may require larger amounts of acid. In suchcases, incorporate this dilution into the calculation. If incom-plete sparging of CO2from IC is suspected, sparge and analyz

49、ethe sample and then repeat the procedure until appropriateconditions are established. In difficult conditions, use of afritted-glass sparger may help.12.4 To measure TOC, inject an appropriate volume of thesample into the analyzer. If external sparging is required toremove IC, inject a sparged sample for the TOC measurement.See 6.3.12.5 To measure TC, inject an appropriate volume ofunsparged sample.13. Calculation13.1 Read carbon values directly from a digital display orprinter, or both.D483903314. Precision and Bias614.1 Collaborative TestThis test method