1.1 本试验方法用于确定在加速好氧-厌氧生物反应器填埋试验环境中塑料材料的好氧降解程度和速率（如拉伸强度、分子量的损失所示，可能导致崩解和碎裂）和厌氧生物降解。随着填埋深度的增加，它可以模拟从需氧环境到厌氧环境的变化。在Tier 1中，将测试塑料材料与生活垃圾混合，然后在密封容器中，在与垃圾填埋场记录的平均温度范围一致的温度范围内，在空气存在的情况下进行有氧预处理和稳定。 tier是一种加速的降解模拟，伴随着氧气消耗和消耗，就像氧化降解进行一样。在按第1级所述进行有氧预处理的第2级塑料样品中，将其暴露于仅对预处理的生活垃圾进行厌氧消化的产甲烷接种物中。厌氧分解和生物降解发生在干燥条件下（大于30 % 总固体）和静态非混合条件。 1.2 该试验方法生成了几种材料的比较数据，不得用于就在垃圾填埋场中放置可降解或可生物降解塑料的好处提出索赔。 索赔必须限于并取决于从每一层获得的结果。 1.2.1 如果仅运行Tier 1，则声明必须说明:将使用测试方法在给定时间段Y天内修改性能/物理特性（例如，机械特性将退化），达到测量百分比X% D3593 （分子量变化）和试验方法 D3826 （抗拉强度变化）在生物活性“生物反应器”填埋场中。报告测量的性能变化百分比和用于测量测试结果的标准，例如，拉伸强度、质量和分子量的变化，以及第节中的残余粒径范围 14 支持此类索赔的范围。 1.2.2 如果同时运行Tier 1和Tier 2，则索赔应说明:是否会在生物活性“生物反应器”填埋场中生物降解到X%的程度，在Y天内根据测试结果确定，该测试结果基于塑料样品转化为二氧化碳和甲烷形式的气态碳的程度，并应根据第节提供 14 支持此类索赔的范围。应注意的是，生物降解测试非常依赖于本实验室测试中选择的条件，当使用不同接种物进行测试时，可能会有很大差异，报告的结果仅适用于测试条件，不排除在其他条件和真实环境下的潜在生物降解。 1.3 本试验方法的第1级旨在通过测量所述塑料的物理和化学特性损失来估计塑料的需氧降解，即崩解和碎裂。然后将试验环境更改为Tier 2厌氧条件，并通过释放的二氧化碳和甲烷气体的组合测量生物降解，作为塑料样品中碳在类似填埋条件下转化为气态碳的百分比。 本试验方法并不能模拟垃圾填埋场中的所有条件，尤其是生物活性垃圾填埋场中的条件。该试验方法更类似于生物反应器填埋场的类型，其中产生的气体被回收或甚至积极促进，或两者兼有，例如，通过接种（厌氧污水污泥的共沉积和厌氧渗滤液再循环）、填埋场中的水分控制（渗滤液再循环）和温度控制（短期注入氧气和加热垃圾）- 循环渗滤液） ( 1- 7. ) . 2. 1.4 本试验方法产生城市固体废物和塑料的部分降解混合物，必要时用于评估垃圾填埋场中不同阶段的需氧降解和厌氧生物降解后与塑料降解相关的生态毒理学风险。 1.5 该方法的预期用途是对在生物反应器填埋场处置后的塑料的需氧降解和厌氧生物降解进行比较和排序。它的设计或目的不是用来支持建议塑料完全降解价值的主张- 规模化填埋场。活动垃圾填埋场的模拟仅允许在指定时间段内测量需氧降解和厌氧生物降解（沼气进化）的百分比。 1.6 尽管测试方法分为两层，但它们旨在模拟垃圾填埋场中的真实降解循环，最好是连续运行，而不是独立或单独运行。 1.7 需要注意的是，任何实验室垃圾填埋场模拟的结果都不能直接外推到实际的处置环境: 与所有ASTM标准一样，最终需要确认真实暴露。这一确认对于垃圾填埋至关重要，因为垃圾填埋场的类型千差万别，有些甚至是内衬很厚的坟墓，这些将严重限制退化。 1.8 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.9 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 没有已知的ISO等效于本标准。 1.10 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 垃圾填埋场内塑料的分解涉及需氧和厌氧环境条件下的过程，这可能会影响由塑料包围或靠近塑料的其他材料的分解。 从需氧条件到厌氧条件的变化速度可能是特定填埋场、垃圾和填充技术的一个特征，因此难以准确评估。不同来源表示天数到月份（参考文献 ( 8. ) 和 ( 9 ) )对于这种变化，传播取决于什么是需氧或厌氧以及环境变化的速度，在这种方法中选择30天作为折衷时间段。（注意，即使氧含量非常低，远低于正常大气浓度，也会促进氧化降解）。 显然，在任何垃圾填埋场中都会有受保护的（袋装、罐装等）有氧活动。目前没有证据或数据支持以下说法:快速降解塑料（与传统的不可降解塑料相比）可以提高填埋气体回收的经济可行性，最大限度地缩短填埋后护理的时间，并使因垃圾填埋场有效期内的降解和生物降解而导致的垃圾体积减少的回收成为可能。 此外，塑料的快速降解和生物降解可能会在垃圾填埋场中造成危险条件，例如细胞移位和整体稳定性。本标准方法用于测定塑料制品在模拟某些填埋条件的生物活性环境中的需氧降解和厌氧生物降解。 5.2 垃圾填埋场中塑料材料的分解很重要，因为大多数垃圾填埋场具有生物活性，并且是一种日益重要的可再生能源。 由于降解发生在垃圾填埋场中，在垃圾填埋场中发生的各种条件下，塑料材料不会产生有毒的代谢物或最终产品，这是一个直接的问题。试验方法完成后剩余的混合物，包含完全或部分降解的塑料材料或提取物，可在适当情况下，随后提交生态毒性试验，见规程 D5951 和指南 D6954 为了详细评估垃圾填埋场中不同程度的塑料分解造成的环境危害，特别是在发生浸出的情况下。 本试验方法旨在评估最佳和非最佳条件下的需氧降解和厌氧生物降解以及毒性。 5.3 限制- 由于垃圾填埋场的建设和运营存在很大差异，并且垃圾填埋场的监管要求差异很大，因此本程序无意模拟所有垃圾填埋场的环境。然而，预计其与生物活性垃圾填埋场的环境非常相似。更具体地说，该程序旨在创造一个标准的实验室环境，允许在加速填埋条件下快速、可重复测定需氧降解性和厌氧生物降解性，同时生产完全和部分分解的生活垃圾与塑料材料的可重复混合物，用于生态毒理学评估。

1.1 This test method is used to determine the degree and rate of aerobic degradation (as indicated by loss of tensile strength, molecular weight, possibly resulting in disintegration and fragmentation) and anaerobic biodegradation of plastic materials in an accelerated aerobic-anaerobic bioreactor landfill test environment. It can simulate the change from aerobic to anaerobic environments over time as landfill depth increases. In Tier 1, the test plastic material is mixed with household waste, then pretreated and stabilized aerobically in the presence of air, in a sealed vessel in a temperature range that is consistent with the average temperature range of those recorded for landfills. The tier is an accelerated simulation of degradation with concomitant oxygen consumption and depletion with time as if oxidative degradation proceeds. In Tier 2 samples of the plastic materials pretreated aerobically as described in Tier 1, are exposed to a methanogenic inoculum derived from anaerobic digesters operating only on pretreated household waste. The anaerobic decomposition and biodegradation occur under dry (more than 30 % total solids) and static non-mixed conditions. 1.2 This test method generates comparative data for several materials and must not be used to make claims regarding benefits of placing degradable or biodegradable plastics in landfills. Claims must be limited to and dependent on the results obtained from each tier. 1.2.1 If only Tier 1 is run, then the claims must state: Will modify the performance/physical properties (for example, mechanical properties will degrade), up to a measured percent, X%, in a given time period, Y days using Test Methods D3593 (Molecular weight change) and Test Method D3826 (tensile strength change) in a biologically active “bioreactor” landfill. Report measured percent property changes and standards used to measure the test results which are, for example, changes in tensile strength, mass and molecular weight, as well as residual particle size ranges in Section 14 to support the extent of such claims. 1.2.2 If both Tier 1 and Tier 2 are run, then claims shall state: Will biodegrade in a biologically active “bioreactor” landfill to a degree, X%, in Y days established by the test results based on the extent to which the plastic sample is converted to gaseous carbon in the form of carbon dioxide and methane and this shall be made available according to Section 14 to support the extent of such claims. It should be noted that biodegradation testing is very dependent on conditions chosen in this laboratory test and may well vary widely when the test is run with different inoculum, The results reported pertain only to the test conditions run and do not rule out potential biodegradation under other conditions and real world environments. 1.3 Tier 1 of this test method is designed to estimate the aerobic degradation of plastics, that is disintegration and fragmentation, only, by measuring the loss of physical and chemical properties of said plastics. The test environment is then changed to that of Tier 2, an anaerobic condition, and biodegradation is measured by a combination of evolved carbon dioxide and methane gases as a percentage of the conversion of carbon in the plastic sample to carbon in the gaseous form under conditions that resemble landfill conditions. This test method does not simulate all conditions found in landfills, especially those found in biologically inactive landfills. This test method more closely resembles those types of bioreactor landfills in which the gas generated is recovered or even actively promoted, or both, for example, by inoculation (co-deposition of anaerobic sewage sludge and anaerobic leachate recirculation), moisture control in the landfill (leachate recirculation), and temperature control (short-term injection of oxygen and heating of re-circulated leachate) ( 1- 7 ) . 2 1.4 This test method produces partially degraded mixtures of municipal solid waste and plastics that, where required, are used to assess the ecotoxicological risks associated with the degradation of plastics after various stages of aerobic degradation and anaerobic biodegradation in a landfill. 1.5 The intended use of this method is for a comparison and ranking of aerobic degradation and anaerobic biodegradation of plastics after disposal in a bioreactor landfill. It is not designed or intended to be used to support claims recommending the value of plastic degradation in full-scale landfills. This simulation of an active landfill allows measurement of the percentage of aerobic degradation and anaerobic biodegradation (biogas evolution) in specified time periods, only. 1.6 Though the test method is in two tiers, they are meant to simulate a real world cycle of degradation in a landfill and are most preferably run consecutively and not independently or separately. 1.7 It is cautioned that the results of any laboratory landfill simulation cannot be directly extrapolated to actual disposal environments: confirmation to real world exposure is ultimately required as with all ASTM Standards. This confirmation is essential for landfill as the types of landfills vary widely, some are even heavily lined, tombs, and these will limit degradation severely. 1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: There is no known ISO equivalent to this standard. 1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Decomposition of a plastic within a landfill involves processes in aerobic and anaerobic environmental conditions that can affect the decomposition of other materials enclosed by or in close proximity to the plastic. The rate of change from aerobic to anaerobic conditions is probably a characteristic of the particular landfill site, its garbage and the filling technique and is therefore difficult to assess with any degree of accuracy. Different sources indicate days to months (Refs ( 8 ) and ( 9 ) ) for this change with the spread dependent on the perspective of what is aerobic or anaerobic and how fast the environment changes, 30 days is chosen in this method as a compromise time period. (Note, even very low levels of oxygen, far below normal atmospheric concentration can promote oxidative degradation). Obviously, there will be pockets of protected (in bags, cans, etc.) aerobic activity enclosed in any landfill. There is currently no evidence or data to support claims that rapid degradation of the plastic (when compared to conventional non-degradable plastic) can increase the economic feasibility of landfill-gas recovery, minimize the duration of after-care of the landfill, and make possible the recovery of the volume reduction of the waste due to degradation and biodegradation during the active life of the landfill. Additionally, it is possible that the rapid degradation and biodegradation of plastics can create hazardous conditions in landfills, such as the shifting of cells and overall stability. This standard method has been developed to permit determination of the aerobic degradation and anaerobic biodegradation of plastic products when placed in biologically active environments simulating some landfill conditions. 5.2 The decomposition of plastic materials in a landfill is of importance, as most landfills are biologically active and are an increasingly significant source of renewable energy. As degradation occurs in a landfill, it is of immediate concern that the plastic materials do not produce toxic metabolites or end products under the various conditions that occur in a landfill. The mixtures remaining after completion of the test method, containing fully or partially degraded plastic materials or extracts can be, when appropriate, submitted subsequently to ecotoxicity testing, see Practice D5951 and Guide D6954 for details, in order to assess the environmental hazards posed by the breakdown of plastics to varying degrees in landfills, especially if leaching occurs. This test method has been designed to assess aerobic degradation and anaerobic biodegradation under optimum and less-than-optimum conditions and toxicity. 5.3 Limitations— Because a wide variation exists in the construction and operation of landfills, and because regulatory requirements for landfills vary greatly, this procedure is not intended to simulate the environments of all landfills. However, it is expected to closely resemble the environment of a biologically active landfill. More specifically, the procedure is intended to create a standard laboratory environment that permits rapid and reproducible determination of the aerobic degradability and anaerobic biodegradability under accelerated landfill conditions, while at the same time producing reproducible mixtures of fully and partially decomposed household waste with plastic materials for ecotoxicological assessment.