Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
Waste Manag. 2013 Oct;33(10):2108-15. doi: 10.1016/j.wasman.2013.01.032. Epub 2013 Mar 7.
Sanitary landfills for Municipal Solid Waste (MSW) disposal have been identified as one of the most important anthropogenic sources of methane (CH4) emissions; in order to minimize its negative effects on the environment, landfill gas (LFG) recovery is a suitable tool to control CH4 emissions from a landfill site; further, the measurement of CH4 emissions can represent a good way to evaluate the effectiveness of LFG recovering systems. In general, LFG will escape through any faults in the landfill capping or in the LFG collection system. Indeed, some areas of the capping can be more permeable than others (e.g. portions of a side slope), especially when considering a temporarily capped zone (covered area that is not expected to receive any further waste for a period of at least 3 months, but for engineering reasons does not have a permanent cap yet). These areas, which are characterized by abnormal emissions, are usually defined as "features": in particular, a feature is a small, discrete area or an installation where CH4 emissions significantly differ from the surrounding zones. In the present study, the influence that specific features have on CH4 emissions has been investigated, based on direct measurements carried out in different seasons by means of a flux chamber to the case study of Palermo (IT) landfill (Bellolampo). The results showed that the flux chamber method is reliable and easy to perform, and the contoured flux maps, obtained by processing the measured data were found to be a suitable tool for identifying areas with abnormal (high) emissions. Further, it was found that a relationship between methane emission rates and landfill side slope can be established. Concerning the influence of the temporary HDPE cover system on CH4 recovery efficiency, it contributed to a significant decrease of the free surface area available for uncontrolled emissions; this aspect, coupled to the increase of the CH4 volumes collected by the LFG recovery system, led to a significant increase of the recovery efficiency.
卫生填埋场是城市固体废物（MSW）处置的重要人为甲烷（CH4）排放源之一；为了将其对环境的负面影响降至最低，垃圾填埋气（LFG）回收是控制垃圾填埋场 CH4 排放的合适工具；此外，CH4 排放量的测量可以作为评估 LFG 回收系统效果的良好方法。一般来说，LFG 会通过垃圾填埋场覆盖层或 LFG 收集系统中的任何故障逸出。事实上，覆盖层的某些区域可能比其他区域更具渗透性（例如边坡的一部分），特别是在考虑临时覆盖区域（预计在至少 3 个月内不会接收任何其他废物的覆盖区域，但出于工程原因尚未设置永久覆盖层）时。这些区域的 CH4 排放量异常，通常被定义为“特征”：特别是，特征是指 CH4 排放量与周围区域明显不同的小而离散的区域或设施。在本研究中，基于在不同季节通过通量室对巴勒莫（意大利）垃圾填埋场（Bellolampo）案例研究进行的直接测量，研究了特定特征对 CH4 排放的影响。结果表明，通量室方法可靠且易于实施，通过处理测量数据获得的等高通量图是识别具有异常（高）排放的区域的合适工具。此外，还发现甲烷排放率与垃圾填埋场边坡之间存在关系。关于临时高密度聚乙烯覆盖系统对 CH4 回收效率的影响，它有助于显著减少自由表面面积，从而减少不受控制的排放；这一方面，加上 LFG 回收系统收集的 CH4 体积增加，导致回收效率显著提高。
