title: Containment and attenuating layers: An affordable strategy that preserves soil and water from landfill pollution.
abstract: The performance of a widely distributed natural clay to attenuate contaminants released from an old landfill was investigated. The objective is to evaluate its potential use as a barrier for waste containment systems. Core samples of the natural clay were collected below the landfill and their parameters distribution with depth was determined. Partition coefficients, retardation factors and percentage values of pollutants concentrations, revealed a rapid decrease of contaminants with depth. The background values of the pollutants were below the maximum limits for drinking and irrigation water and with no need of reactors, collectors, aeration or recirculation systems. Impermeable waste capping is discouraged in order to decrease leachate toxicity, decomposition time and conservative species, and in order to avoid high-reducing conditions that would mobilize redox-sensitive contaminants. A review on leachate-composition evolution and on natural-attenuation processes was undertaken to understand the interactions leachate-substratum, which is essential to properly estimate the leachate transport and implement the attenuation strategy. This strategy complements the traditional containment one regarding (1) the susceptibility of engineering liners to fail, (2) the inevitable diffusion of contaminants through them, (3) the remaining high number of old landfills before the requirements of liner systems and (4) the low-cost and feasibility for developing countries.
authors: Department of Geology and Geochemistry, Faculty of Science, Autonomous University of Madrid, Campus Cantoblanco, C/Fco. Tomás y Valiente 7, 28049 Madrid, Spain. Electronic address: Mercedes.Regadio@chem.kuleuven.be.
authors: Mercedes
authors: M
authors: Regadío
authors: Department of Geology and Geochemistry, Faculty of Science, Autonomous University of Madrid, Campus Cantoblanco, C/Fco. Tomás y Valiente 7, 28049 Madrid, Spain.
authors: Ana I
authors: AI
authors: Ruiz
authors: Unit of Soils Conservation and Recovery, Department of Environment, CIEMAT, Avda. Complutense, 40, 28040 Madrid, Spain.
authors: Manuel
authors: M
authors: Rodríguez-Rastrero
authors: Department of Geology and Geochemistry, Faculty of Science, Autonomous University of Madrid, Campus Cantoblanco, C/Fco. Tomás y Valiente 7, 28049 Madrid, Spain.
authors: Jaime
authors: J
authors: Cuevas
mesh_terms: D000538:Aluminum Silicates / Q000032:analysis*; D000077215:Clay; D004787:Environmental Pollution / Q000191:economics / Q000517:prevention & control*; D013030:Spain; D064091:Waste Disposal Facilities; D018505:Waste Management / Q000191:economics / Q000379:methods*; D014877:Water Pollution, Chemical / Q000191:economics / Q000517:prevention & control*
chemical_list: D000538:Aluminum Silicates; D000077215:Clay
keywords: Attenuation strategy; Clay; Landfill leachate; Migration; Sorption