Department of Geology and Geochemistry, Faculty of Science, Autónoma University of Madrid, Campus Cantoblanco, C/Fco. Tomás y Valiente 7, 28049 Madrid, Spain.
Waste Manag. 2012 Mar;32(3):482-97. doi: 10.1016/j.wasman.2011.11.008. Epub 2011 Dec 12.
The long-term effectiveness of the geological barrier beneath municipal-waste landfills is a critical issue for soil and groundwater protection. This study examines natural clayey soils directly in contact with the waste deposited in three landfills over 12 years old in Spain. Several physicochemical and geological parameters were measured as a function of depth. Electrical conductivity (EC), water-soluble organic carbon (WSOC), Cl(-), NH(4)(+), Na(+) and exchangeable NH(4)(+) and Na(+) were used as parameters to measure the penetration of landfill leachate pollution. Mineralogy, specific surface area and cationic-exchange capacities were analyzed to characterize the materials under the landfills. A principal component analysis, combined with a Varimax rotation, was applied to the data to determine patterns of association between samples and variables not evident upon initial inspection. The main factors explaining the variation in the data are related to waste composition and local geology. Although leachates have been in contact with clays for long time periods (13-24 years), WSOC and EC fronts are attenuated at depths of 0.2-1.5m within the clay layer. Taking into account this depth of the clayey materials, these natural substrata (>45% illite-smectite-type sheet silicates) are suitable for confining leachate pollution and for complying with European legislation. This paper outlines the relevant differences in the clayey materials of the three landfills in which a diffusive flux attenuation capacity (A(c)) is defined as a function (1) of the rate of decrease of the parameters per meter of material, (2) of the age and area of the landfill and (3) of the quantity and quality of the wastes.
垃圾填埋场下方地质屏障的长期有效性是土壤和地下水保护的关键问题。本研究考察了西班牙三个有 12 年历史的垃圾填埋场中直接与废物接触的天然粘性土。测量了几个物理化学和地质参数作为深度的函数。电导率 (EC)、水溶性有机碳 (WSOC)、Cl(-)、NH(4)(+)、Na(+) 和可交换的 NH(4)(+) 和 Na(+) 被用作测量垃圾渗滤液污染穿透的参数。分析了矿物学、比表面积和阳离子交换容量，以表征垃圾填埋场下的材料。应用主成分分析，结合 Varimax 旋转，对数据进行分析，以确定样本与变量之间的关联模式，这些模式在初始检查时并不明显。解释数据变化的主要因素与废物组成和局部地质有关。尽管渗滤液已经与粘土接触了很长时间（13-24 年），但在粘土层内 0.2-1.5m 的深度处，WSOC 和 EC 前缘被衰减。考虑到粘土材料的这个深度，这些天然基质（>45%伊利石-蒙脱石型片状硅酸盐）适合限制渗滤液污染，并符合欧洲法规。本文概述了三个垃圾填埋场中粘土材料的相关差异，其中定义了扩散通量衰减能力 (A(c)) 作为以下函数：(1) 参数每米材料的减少率，(2) 填埋场的年龄和面积，以及 (3) 废物的数量和质量。
