Transferencia de elementos traza potencialmente tóxicos en cultivos desarrollados en suelos con influencia minera

Résumé

ABSTRACT: In the restoration and recovery projects of contaminated areas by mining activities, it should be highlighted those affecting agricultural areas, by the transference of the potentially toxic trace elements (PTEs) soil to biota in the soil-plant-biotic chain sequence. In this PhD thesis, an experimental study is carried out in a greenhouse in order to be able to model processes that can take place in restored soils with a mining origin. The study is developed with different consumption plant species, "Baby" lettuce, leek, onion, broccoli, alfalfa, iceberg lettuce and spinach, on natural soil (T1) or ground reference; Technosoils: T2 (contaminated soil: 50% vegetable + mining soil), T3 (75% contaminated soil + 25% construction and demolition waste), T4 (75% contaminated soil + 25% limestone Filler) and contaminated soil mining (TC). The purpose of this is to appraise the construction and demolition waste (CDW) and other waste with a high concentration in filler limestone and establish the arsenic accumulation factors for the selected plant species. It is observed that in the studied soils are limiting factors for the growth of crops, which prevent their normal development, being related to soil salt content, pH and carbonate content. The arsenic content of the experimental species, grown in uncontaminated soil and reclaimed soils are within the value ranges found in the literature. However, when contaminated soil is grown, its content varies widely depending on the species and even the variety, being the highest one for alfalfa (Fabaceas), chard (Amarantacea), and iceberg lettuce (Asteracea). The accumulation factors (FA) for arsenic calculated from those contained in plant and rhizosphere of the plants studied, present values generally lower than 0.01 and the arsenic transference to the plant will depend on the arsenic content, which is bioavailable in the soil. In areas influenced by mining sites, and in order to reduce the exposure of arsenic in the diet, it would be necessary to require exhaustive zoning pollution surveys of such places for an agricultural use. Making Technosoils with limestone filler and CDWs can replace the action of the natural attenuation of pollution, which takes place in the surrounding areas of mining sites when there are soils with calcium carbonate and clay.