1、Designation: D5975 17Standard Test Method forDetermining the Stability of Compost by Measuring OxygenConsumption1This standard is issued under the fixed designation D5975; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 covers the stability of a compostsample by measuring oxygen consumption after exposure ofthe test co
3、mpost to a well-stabilized compost under controlledcomposting conditions on a laboratory scale involving activeaeration. This test method is designed to yield reproducible andrepeatable results under controlled conditions that resemble theend of the active composting phase. The compost samples areex
4、posed to a well-stabilized compost inoculum that is preparedfrom the organic fraction of municipal solid waste or wastesimilar to the waste from which the test materials are derived.The aerobic composting takes place in an environment wheretemperature, aeration, and humidity are monitored closely an
5、dcontrolled.1.2 This test method yields a cumulative amount of oxygenconsumed/g of volatile solids in the samples over a four-dayperiod. The rate of oxygen consumption is monitored as well.1.3 This test method is applicable to different types ofcompost samples including composts derived from wastes,
6、such as municipal solid waste, yard waste, source-separatedorganics, biosolids, and other types of organic wastes that donot have toxicity levels that are inhibitory to the microorgan-isms present in aerobic composting systems.1.4 The values stated in SI units are to be regarded asstandard. No other
7、 units of measurement are included in thisstandard.1.5 There is no similar or equivalent ISO method.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, health,
8、 and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 8.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decisi
9、on on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1293 Test Methods for pH of WaterD2908 Practi
10、ce for Measuring Volatile Organic Matter inWater by Aqueous-Injection Gas ChromatographyD3590 Test Methods for Total Kjeldahl Nitrogen in WaterD4129 Test Method for Total and Organic Carbon in Waterby High Temperature Oxidation and by CoulometricDetectionD5338 Test Method for Determining Aerobic Bio
11、degrada-tion of Plastic Materials Under Controlled CompostingConditions, Incorporating Thermophilic TemperaturesD5907 Test Methods for Filterable Matter (Total DissolvedSolids) and Nonfilterable Matter (Total Suspended Solids)in WaterD8001 Test Method for Determination of Total Nitrogen,Total Kjelda
12、hl Nitrogen by Calculation, and Total Phos-phorus in Water, Wastewater by Ion Chromatography2.2 APHA-AWWA-WPCF Standards:32540 D Total Suspended Solids Dried at 103105 C2540 E Fixed and Volatile Solids Ignited at 550 C3. Terminology3.1 Definitions of terms in this test method appear inTerminology D8
13、83.4. Summary of Test Method4.1 This test method consists of the following:4.1.1 Selecting a compost sample for the determination ofthe stability.1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03 on Treatment,
14、Recovery and Reuse.Current edition approved Dec. 1, 2017. Published December 2017. Originallyapproved in 1996. Last previous edition approved in 2010 as D5975 96 (2010).DOI: 10.1520/D5975-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serv
15、iceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Standard Methods for the Examination of Water and Wastewater, 17th Edition,1989, American Public Health Association, 1740 Broadway, New York, NY, 19919.Copyright ASTM In
16、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standard
17、s, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.14.1.2 Producing a fully stabilized compost from a similarwaste stream under well-controlled laboratory conditions.4.1.3 Exposing the compost test samples to the fully stabi-lized compost
18、 under controlled composting conditions.4.1.4 Measuring the oxygen consumption rate and deter-mining the cumulative oxygen consumption.4.2 Obtaining the level of stability from the cumulativeoxygen consumption.5. Significance and Use5.1 A measurement of compost stability is needed forseveral reasons
19、. It aids in assessing whether the compostingprocess has proceeded sufficiently far to allow the finishedcompost to be used for its intended application. A differentcompost stability may be required for different applications ofthe compost.5.2 A measurement of compost stability also is needed toveri
20、fy whether a composting plant is processing the waste topreviously agreed levels of stability. This measurement isuseful in the commissioning of composting plants and theverification of whether plant operators are satisfying permitrequirements.5.3 The level of compost stability also will indicate it
21、spotential to cause odors if the compost is stored withoutaeration, as well as the level to which it has been hygienizedand how susceptible the compost is to renewed bacterial andpossible pathogenic activity. Compost stability is an importantparameter with regard to phytotoxicity and plant tolerance
22、 ofthe compost.5.4 The determination of compost stability will allow theselection of well-performing composting technologies, as wellas the safe application of compost in its various markets. Themethod indicates a degree of stability, but does not necessarilyindicate that one level is preferable ove
23、r another level ofstability.6. Apparatus6.1 Stabilized Compost Inoculum Preparation Bin (see Fig.1):6.1.1 A stabilized compost inoculum preparation bin with avolume of 100 to 200 L, with insulation sufficient to maintaincomposting temperatures of 50 to 65 C during a period of atleast two weeks when
24、composting similar waste as the wastefrom which the samples were derived, and equipped with airdistribution plate, inlet and outlet, and airtight lid.6.1.2 Pressurized Air, provided to the composting bin at aprecise and controllable rate up to 200 L/kg waste/day.6.1.3 Thermometer, with temperature m
25、easurement up to80 C (62 C).6.1.4 Suitable devices for measuring oxygen and CO2(optional) concentrations in the exhaust air of the compostingbin, such as sensors or appropriate gas chromatography.FIG. 1 Optional Set-Up Compost Preparation BinD5975 1726.2 Composting Apparatus (see Fig. 2):6.2.1 A ser
26、ies of at least nine composting vessels (one testsubstance, one blank, one positive reference, all in threereplicates) of 2 to 5 L of volume.6.2.2 Incubators, water baths, or other temperature control-ling means capable of maintaining the temperature of thecomposting vessels at 25 C (62 C).6.2.3 Pre
27、ssurized Air System, providing H2O-saturated airto each of the composting vessels at the appropriate aerationrates.6.2.4 Suitable devices for measuring oxygen concentrationin the exhaust air of the composting vessels, such as specificsensors or appropriate gas chromatography.6.3 Miscellaneous:6.3.1
28、Balance (61 mg), to weigh sample and stabilizedcompost.6.3.2 Scales (60.1 kg), to weigh composting waste forstabilized compost production.6.3.3 Normal laboratory glassware, equipment, and chemi-cals.6.3.4 Suitable devices and analytical equipment for measur-ing dry solids (at 105 C), volatile solids
29、 (at 550 C), volatilefatty acids by aqueous-injection chromatography, and totalKjeldahl nitrogen.7. Reagents and Materials7.1 Analytical-grade cellulose (microcrystalline, as used inthin-layer chromatography) with a particle size of less than10 m, for use as a positive control.8. Hazards8.1 This tes
30、t method requires the use of hazardous chemi-cals. Avoid contact with the chemicals and follow manufactur-ers instructions and Safety Data Sheets (SDS).8.2 The waste materials used for the production of stabilizedcompost, or the compost samples may contain sharp objects.Take care when handling.8.3 T
31、he composting vessels are not designed to withstandhigh pressures. The system should be operated at close toambient pressure.8.4 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 app
32、ro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.9. Stabilized Compost9.1 The stabilized compost, which serves as an inoculumand the test matrix, should be well-aerated compost two to fourmonths old, coming from the organic
33、 fraction of municipalsolid waste or source-separated organics, and sieved over ascreen of 10 mm. It is recommended that the stabilizedcompost control consumes 15 to 80 mg of oxygen/g of volatilesolids over the four-day test period. The stabilized compostmust have a total solids content between 50 a
34、nd 60 % on wetweight, an ash content of less than 70 % on total solids, a pHbetween 7 and 8, and be free of volatile fatty acids (less thanFIG. 2 Optional Set-Up Using Gas Chromatograph (see also Test Method D5338)D5975 173100 mg/L as acetic acid). The C/N ratio should be between 10and 20 and the C/
35、P ratio between 30 and 60.9.2 The stabilized compost should be as free as possible oflarger inert materials (for example, glass, stones, metals).These items should be removed manually to produce a homo-geneous material.10. Test Samples10.1 The test sample must be representative of the compostthat is
36、 being assessed for compost quality. Preferably the testsample should be a composite of various grab samples takenthroughout the pile. Otherwise, take samples at various depthsof a compost pile and analyze these compost samples sepa-rately to assess any variations within the compost pile itself.10.2
37、 When adding the test sample compost to the stabilizedcompost, all basic composting parameters, such as oxygen inthe composting vessel, porosity, and moisture content shouldbe adjusted so as to make a good composting process possible.Oxygen levels in the composting vessel should be at least 6 %at al
38、l times and no free-standing water nor clumps of materialshould be present.11. Procedure11.1 Preparation of the Samples:11.1.1 Obtain the stabilized compost inoculum from aproperly operating laboratory-scale composting bin processinga waste similar to the waste from which the test samples arederived
39、.11.1.1.1 Screen the stabilized compost to less than 10 mmand manually remove and discard any large inert items (piecesof glass, stone, wood) that went through the 10-mm screen.Determine on the fraction less than 10 mm the volatile solids,dry solids, and carbon, nitrogen, and phosphorus contentsacco
40、rding to Test Methods D8001, D5907, D3590, D4129, andAPHA Test Methods 2540 D and 2540 E. Also determine pHand volatile fatty acids as described in 11.4.2. Add ammoniumchloride if the C/N ratio is more than 20 and adjust to a C/Nratio of 15.Add NaH2PO4if the C/P is more than 60 and adjustto a C/P ra
41、tio of 45.11.1.1.2 Compost samples stored for more than a few daysshould be refrigerated.11.1.1.3 Samples obtained from compost operating at ther-mophilic temperatures should be held at room temperature for24 h to allow re-establishment of mesophilic microorganisms.411.1.2 Determine the volatile sol
42、ids and dry solids of all thetest sample composts in accordance with APHA Test Meth-ods 2540 D and 2540 E.11.1.3 Weigh out precise amounts of stabilized compostinoculum and test sample compost (roughly 500 g of each percomposting vessel) and mix thoroughly. The relation betweenthe dry weight of the
43、stabilized compost and the dry weight oftest material should be about 1:1. Adjust with water the drysolids content of the mixture to approximately 50 %, and addthe mixture to three composting vessels. Weigh the vesselswith contents.11.1.4 The blank consists of the stabilized compost only,containing
44、about 1000 g wet weight/composting vessel foreach of the three replicates. For the positive control, add 50 gof microcrystalline cellulose to 1000 g of stabilized compostfor each of the three replicates.11.2 Start-Up ProcedureInitiate aeration of the compost-ing vessels with airflow rates that are s
45、ufficiently high to ensurethat oxygen levels do not drop below 6 % in the exhaust air.Oxygen levels should be closely controlled during the first 36h and measured at least four times daily. Adjust air-flow ratesas needed for the remainder of the test.11.3 Operating Procedure:11.3.1 Incubate the comp
46、osting vessels in the dark for aperiod of four days. Keep the temperature at 25 C (62 C) forthe duration of the test. The incubation time may be extendedif the rate of oxygen consumption during the last 24 h is higherthan during the previous 24 h in the vessels containing thesamples.11.3.2 Check O2c
47、oncentrations in the outgoing air, fourtimes daily, with a maximum time interval of 5 h.11.3.3 Check airflow daily at the connections before andafter the composting vessels and at the outlets, ensuring that noleaks are present in the complete system. Adjust airflow tomaintain an oxygen concentration
48、 of at least 6 % v/v in theexhaust air.11.3.4 Ensure proper composting conditions and shakecomposting vessels after the first day of testing.11.4 End of the Test:11.4.1 At the end of the test, weigh the vessels with thecontents and determine the dry solids content remaining in thecompost.11.4.2 Meas
49、ure the pH in conformance with Test MethodsD1293. Measure the pH by diluting the sample to a 5:1 w/wmixture of distilled water to compost, mix by shakingmanually, and measure immediately. If the pH is less than 7,measure the volatile fatty acids in accordance with PracticeD2908 in the liquid phase after centrifugation of the dilutedsample at 3000 G forces. The volatile fatty acids must be below2000 mg/L as acetic acid.12. Calculation12.1 Determine the volumetric cumulative oxygen con-sumption for each composting vessel over the whole testperiod, usi
