1、Designation: D5929 96 (Reapproved 2009)Standard Test Method forDetermining Biodegradability of Materials Exposed toMunicipal Solid Waste Composting Conditions by CompostRespirometry1This standard is issued under the fixed designation D5929; the number immediately following the designation indicates
2、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 test method covers the biodegradation prope
3、rties ofa material by reproducibly exposing materials to conditionstypical of municipal solid waste (MSW) composting. A mate-rial is composted under controlled conditions using a syntheticcompost matrix and determining the acclimation time, cumu-lative oxygen uptake, cumulative carbon dioxide produc
4、tion,and percent of theoretical biodegradation over the period of thetest. This test method does not establish the suitability of thecomposted product for any use.1.2 The values stated in both inch-pound and SI units are tobe regarded separately as the standard. The values given inparentheses are fo
5、r information only.1.3 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
6、use.2. Referenced Documents2.1 ASTM Standards:2D513 Test Methods for Total and Dissolved Carbon Diox-ide in WaterD1129 Terminology Relating to WaterD1293 Test Methods for pH of WaterD2908 Practice for Measuring Volatile Organic Matter inWater by Aqueous-Injection Gas Chromatography2.2 APHA-AWWA-WEF
7、Standard Methods:2540G Total, Fixed, and Volatile Solids in Solid and Semi-solid Samples33. Terminology3.1 DefinitionsDefinitions of terms applying to this testmethod appear in Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 acclimation time, nthe time required for the oxy
8、genuptake to reach 10 % of the total measured cumulative oxygenuptake.43.2.2 oxygen uptake, nthe cumulative oxygen consumedby the organisms during the test.3.2.3 theoretical carbon dioxide production (ThCDP),nthe maximum carbon dioxide that can be produced by amaterial as calculated by the carbon co
9、ntent of the material.3.2.4 theoretical oxygen uptake (ThOU), n the maximumoxygen consumption required to fully oxidize a material basedon the elemental content of the material.3.2.5 virgin newsprintnonprinted newspaper roll stock.4. Summary of Test Method4.1 This test method consists of the followi
10、ng:4.1.1 The samples are prepared by cutting or forming thematerial into the form it would most likely be seen in the wastestream. A theoretical maximum carbon dioxide production andoxygen uptake are determined from an elemental analysis.4.1.2 An inoculum is obtained from a municipal MSW oryard wast
11、e compost facility. It is procured from a static pilethat has been composting for at least two months.4.1.3 The synthetic MSW is prepared from virgin newsprint,pine bark or wood chips, corn starch, corn oil, bovine casein,and urea. A buffer/dilution water is prepared from magnesium,calcium, iron and
12、 a phosphate buffer.4.1.4 The test material, synthetic compost, inoculum, anddilution water are combined and placed in a highly insulatedreactor which monitors oxygen consumption and temperatureand captures all evolved carbon dioxide.4.1.5 The system is monitored, and oxygen uptake rates,temperature
13、 profiles, and total carbon dioxide produced arerecorded.1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03 on Treatment,Recovery and Reuse.Current edition approved Sept. 1, 2009. Published November 2009. Origi
14、nallyapproved in 1996. Last previous edition approved in 2004 as D5929-96(2004). DOI:10.1520/D5929-96R09.2For 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 standar
15、ds Document Summary page onthe ASTM website.3Available from American Public Health Assoc., 1015 15th Street, NW,Washington, DC 20005, Standard Methods for the Examination of Water and WasteWater, 18th ed., 1992.4Tabak, Henry H. and Lewis, Ronald F., CEC/OECD Ring Test of RespirationMethod for Determ
16、ination of Biodegradability, U. S. Environmental ProtectionAgency, pp. 13.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.6 The total oxygen uptake and carbon dioxide producedare compared with the theoretical values obtained from
17、 theelemental analysis, and a percent of biodegradation is gener-ated. Possible negative effects of the material are evaluated byobserving the acclimation time of the synthetic MSW andevaluating the oxygen uptake rate.5. Significance and Use5.1 As the crisis in solid waste continues to grow, MSWcomp
18、osting is increasingly being considered as one componentin the overall solid waste management strategy. The volumereduction achieved by composting, combined with the produc-tion of a usable end product, is resulting in increasing numbersof municipalities analyzing and selecting MSW composting asan a
19、lternative to incineration or to reduce reliance on landfilldisposal. This test method will help determine the effect ofmaterials on the compost process and establish if the materialcan be properly disposed through solid waste compostingfacilities.55.2 This test method attempts to provide a simulati
20、on of theoverall compost process while maintaining reproducibility.Exposing the test material with several other types of materialsthat are typically in MSW provides an environment whichprovides the key characteristics of composting: material not ina sole carbon source environment which allows co-me
21、tabolism, compost system is self heating, and provides adirect measurement of organism respiration.6. Apparatus6.1 Compost Respirometry Apparatus (see Fig. 1):6.1.1 A minimum of six reactors, 2 to 6-L volume, with thetest material in triplicate and the controls in triplicate. Thereactors should be s
22、urrounded with efficient insulation tominimize heat loss and be gastight. Insulation should be 8 cmof urethane foam or equivalent.6.1.2 Tubing, with high resistance to gas permeation.6.1.3 Peristaltic Pump, to control and maintain gas flowthrough each reactor.6.1.4 4-L Scrubber Vessel, for each reac
23、tor fitted with ascrubber solution sampling port.6.1.5 Differential Pressure Switch, for each reactor thatactuates between 2 and 5 in. (51 and 127 mm) of water.6.1.6 Solenoid and Mass Flowmeter, to control and measurethe addition of pure (99.997 + ) oxygen to system.6.1.7 Temperature Probe, situated
24、 in the middle of thecompost.6.1.8 Data Acquisition and Control System, for the measure-ment of temperature and the control and measurement of theoxygen addition.6.2 Miscellaneous:6.2.1 Temperature Control Room, or hood to maintain theexternal temperature of the apparatus at 40C.6.2.2 Flow Meter, to
25、 measure recirculation flow in eachreactor (optional).6.2.3 Computer Control of Peristaltic Pump, for automaticrecirculation flow control (optional).6.3 Suitable devices for the measurement of pH, dry solids(105C), elemental analysis of material, carbon dioxide contentof scrubbers, weight, and volum
26、e of the final compost material.7. Test Materials7.1 The test materials can be in any form as long as itsdimensions do not exceed 3 by 3 by 12 cm. The test materialsshould be in the form that they would be seen in the wastestream. A representative sample must be obtained by usingappropriate ASTM met
27、hods or other documented method.7.2 Analyze the test materials for carbon, hydrogen, nitro-gen, oxygen, phosphorus, sulfur, and any other elements thatare suspected to be present at a level to effect oxygen uptake.The ThOU must be calculated for each material.7.3 Calculate the ThCDP from the carbon
28、content of the testmaterial.7.4 The nitrogen content of the synthetic MSW should beadjusted if the C/N ratio is greater than 40:1. This is accom-plished by adjusting the urea content of the synthetic MSW.The synthetic MSW has adequate nitrogen to support theaddition of up to 35 g of carbon before th
29、e ratio exceeds 40:1.If the urea content is adjusted, all reactors including controlsmust contain the same concentration of urea.5Biocycle: Journal of Waste Recycling Staff, eds., The Biocycle Guide toComposting Municipal Wastes, JG Press, Inc., 1989.NOTE 1The compost respirometer features a 4-L rea
30、ctor vessel (A)insulated with 8 cm of urethane foam. The atmosphere is drawn throughthe reactor by a peristaltic pump (B) to maintain aeration. The effluentgases are passed through a 4-L scrubber vessel (C) containing 1.5 L of 5M NaOH to remove any carbon dioxide from the effluent gas stream.Samples
31、 are drawn from this scrubber solution during the evaluation todetermine the carbon dioxide released by the compost. As the microor-ganisms consume the oxygen in the system, a pressure drop occurs and isdetected by a highly sensitive pressure switch (D). This signals the dataacquisition and control
32、system (G) and the oxygen is replaced with purebottled oxygen by a solenoid (E) and the amount added is measured by amass flowmeter (F). The gasses are then returned to the reactor. Athermocouple (H) is centered in the test reactor to monitor the temperatureof the compost. The system is sealed to pr
33、event interference frombarometric fluctuations.FIG. 1 Compost Respirometer Functional DiagramD5929 96 (2009)28. Reagents and Materials8.1 Scrubber Solution, containing 3.25 N NaOH in distilledwater. Store in a gas-tight plastic container. Add 30 mg ofphenolphthalein to the solution to indicate scrub
34、ber exhaustion.8.2 Dilution/Buffer Solution, containing the following:Chemical Purpose Concentration, g/LKH2PO4phosphate buffer 6.8Na2HPO47H2O phosphate buffer 55.6MgSO47H2O nutrient 0.0225CaCl2nutrient 0.0275FeCl36H2O nutrient 0.000258.3 Synthetic Municipal Solid Waste, containing the follow-ing:6,
35、7Constituent Chemical Used Dry Weight, %Cellulosics shredded, virgin newsprint 41Inerts pine bark or wood chips 39Carbohydrates corn starch 5.2Lipids corn oil 5.4Proteins bovine casein 2.0Organic nitrogen urea 1.4Buffer/Nutrient as listed 5.88.4 Polyethylene, or another nonbiodegradable material ist
36、he negative control material. It should be in the same form asthe test materials to provide the same physical conditions in allreactors. The synthetic MSW acts as a positive control to verifythe viability of the inoculum, see 13.4 for requirements.9. Hazards9.1 This test method requires the use of h
37、azardous chemi-cals. Avoid contact with the chemicals and follow the manu-facturers instructions and Material Safety Data Sheets.9.2 This test method does not address all of the health andsafety issues related to its use. It is the responsibility of theuser to establish appropriate safety measures.9
38、.3 High-purity high-pressure gases can be dangerous if nothandled correctly. Follow all safety precautions and monitorthe system often to ensure proper operation.10. Inoculum10.1 The inoculum should be obtained from MSW or yardwaste that has properly composted for two to four months. Thecompost shou
39、ld be screened with a 2g/kg, the reactors havesoured and the results are invalid.12. Calculation12.1 Calculate the theoretical oxygen uptake from the per-cent by weight of each of the elements:ThOU mg O2/mg! 5 C/37.5 1 H/12.5 1 N/29.21 P/48.4 1 S/66.7 2 O/100 (1)12.2 The theoretical carbon dioxide p
40、roduction is alsodetermined from the elemental analysis and is calculated asfollows:ThCDP mg CO2/mg! 5 %byweight carbon! 3.667! (2)12.3 Calculate the oxygen uptake due to the test material bysubtracting the mean of the control reactors from each of thetest reactors at each data point.12.4 Calculate
41、the total carbon dioxide produced by sub-tracting the mean of the control analytical results from each ofthe test reactors.12.5 Calculate the percent of theoretical of the total oxygenuptake and carbon dioxide by dividing the measured totals bythe calculated ThOU or ThCDP and multiplying by 100.12.6
42、 The acclimation time for the test material and compostmatrix can be determined at the point which the oxygen uptakeexceeded 10 % of the total oxygen uptake for that reactor.12.7 If the test materials oxygen uptake curve shows anegative slope at the beginning of the curve, the test materialacclimati
43、on time is calculated at the point were the slope of theoxygen uptake curve becomes positive for a minimum of 24 h.13. Interpretation of Results13.1 The acclimation time can provide valuable informationon the toxicity or inhibition effects of the test material.13.2 The percent of theoretical oxygen
44、uptake is an excel-lent measure of the biodegradability of the test material sinceit represents the mineralization of carbon in addition to allother oxidative reactions.13.3 The percent of theoretical carbon dioxide productioncan be used to measure biodegradability (with limitations) andcan be used
45、to correlate results with other carbon dioxide basedtest methods.13.4 To ensure an active and viable inoculum, the totaloxygen uptake for the control reactors should exceed 80 g. Ifthis is not observed over the 45 days then the test must beregarded as invalid and should be repeated with new inoculum
46、.14. Report14.1 Report the following information and data with stan-dard deviations and 95 % confidence intervals when appropri-ate:14.1.1 Information on source, dry solids, storage conditions,and age of the inoculum,14.1.2 The ThOU and ThCDP of test materials with elemen-tal analysis results,14.1.3
47、 Test material physical characterization includingsize, shape, weight, dry weight, initial and final reactorobservations, and sampling technique used,14.1.4 Percent of ThOU and ThCDP for each test material,14.1.5 Total oxygen uptake and oxygen uptake versus timeplots for entire reactors and test mat
48、erials only. Rate plots ifapplicable,14.1.6 Acclimation times for test materials,14.1.7 Total carbon dioxide produced and carbon dioxideversus time plots if multiple samples were analyzed during thetest,14.1.8 Temperature plots of each reactor,14.1.9 Total weight loss of reactor contents and dry wei
49、ghtof end reactor contents,14.1.10 Final pH of compost, investigative results if pH isbelow seven, and14.1.11 Full description of test apparatus and documenta-tion of any variations from this test method.15. Precision and Bias15.1 The precision and bias of this test method is beingdetermined.15.2 Typical oxygen uptake and temperature plots are pre-sented in Fig. 2 and Fig. 3. Within-test reproducibility fromthree different test runs are presented in Table 1.Run1isthecontrol reactors with pine bark, Run 2 is with fresh wood chips,and Run 3 is with previously used wo
