Ritzkowski M, Heyer K-U, Stegmann R
Institute of Waste Management, Hamburg University of Technology, Harburger Schlossstr. 36, D-21079 Hamburg, Germany.
Waste Manag. 2006;26(4):356-72. doi: 10.1016/j.wasman.2005.11.009. Epub 2006 Jan 26.
Results of investigations from many old landfills in Germany and Europe indicate that significant emissions occur under conventional landfill operating conditions (i.e., anaerobic conditions). Significant emissions via the gas phase are predicted to last at least three decades after landfill closure, while leachate emissions are predicted to continue for many decades, potentially even lasting for centuries. When considering the specific type and quality, and quite often lack of, protection barriers associated with old landfills, these leachate and gas emissions may result in a significant negative impact on the environment. However, complete sealing of the landfill only temporarily reduces emissions because dry-conservation of the biodegradable waste fraction results, thus not allowing any severe reduction in the emission and hazardous potential of the landfill to occur. If noticeable damage of the surface capping system occurred in these landfills, infiltrating water would restart the interrupted emission formation. In contrast, aerobic in situ stabilization by means of low pressure aeration attempts to stabilize and modify the inventory of organic matter inside the landfill, acting to reduce the emission potential in a more sustainable manner. By enabling faster and more extensive aerobic degradation processes in the landfill (compared with anaerobic processes), the organics (e.g., hydrocarbons) are degraded significantly faster, resulting in an increased carbon discharge via the gas phase, as well as reduced leachate concentrations. Because carbon dioxide (CO(2)) is the main compound in the extracted off-gas (instead of methane (CH(4)), which dominated under anaerobic landfill conditions), the negative impact of diffuse LFG emissions towards an increased global warming effect may be significantly lowered. With respect to leachate quality, a reduction of organic compounds as well as ammonia-nitrogen can be expected. In addition to these positive ecological effects, aerobic in situ stabilization is associated with significant cost savings potential due to both quantitative and qualitative reductions in the aftercare period. This paper describes the fundamental processes and implications of in situ landfill aeration. Additionally, possible criteria for defining an endpoint of the active aeration process are presented and discussed.
来自德国和欧洲许多老垃圾填埋场的调查结果表明，在传统垃圾填埋场运行条件下（即厌氧条件）会产生大量排放。预计在垃圾填埋场关闭后，气相中的大量排放将持续至少三十年，而渗滤液排放预计将持续数十年，甚至可能持续数百年。考虑到老垃圾填埋场相关的特定类型和质量，以及通常缺乏的保护屏障，这些渗滤液和气体排放可能会对环境造成重大负面影响。然而，对垃圾填埋场进行完全密封只能暂时减少排放，因为这会导致可生物降解废物部分的干保存，从而无法大幅降低垃圾填埋场的排放和危险潜力。如果这些垃圾填埋场的表面覆盖系统出现明显损坏，渗入的水将重新启动中断的排放形成。相比之下，通过低压曝气进行好氧原位稳定化试图稳定和改变垃圾填埋场内的有机物存量，以更可持续的方式降低排放潜力。通过在垃圾填埋场中实现比厌氧过程更快、更广泛的好氧降解过程，有机物（如碳氢化合物）的降解速度显著加快，导致气相中的碳排放量增加，同时渗滤液浓度降低。由于提取的废气中的主要化合物是二氧化碳（CO₂）（而不是在厌氧垃圾填埋场条件下占主导的甲烷（CH₄）），扩散的垃圾填埋气排放对全球变暖效应增加的负面影响可能会显著降低。关于渗滤液质量，可以预期有机化合物以及氨氮会减少。除了这些积极的生态影响外，由于后期维护期在数量和质量上的减少，好氧原位稳定化还具有显著的成本节约潜力。本文描述了垃圾填埋场原位曝气的基本过程和影响。此外，还提出并讨论了定义主动曝气过程终点的可能标准。
