Abstract—In this research we studied the feasibility of applying phytoremediation in the mine tailings at La Concha site. The extraction efficiency of heavy metals was studied, as well as the tolerance to high pollution and biomass generation of Lolium multiflorum, known as Italian ryegrass, in the aggressive soils composed almost entirely by mine wastes. Ryegrass seeds were grown in mine tailings containing Cu, Mn, Zn, and Pb concentrations of around 800, 4600, 3200, and 5400 ppm respectively. Triplicate analyses of soils without treatment and with treatments consisting in organic matter (OM) additions were carried out during 90 days. Italian ryegrass has a high tolerance to polluted mine tailings, although the addition of small quantities of organic matter improves the extraction of metals. The highest metals uptake from tailings was achieved through treatment with 20 % OM additions, with varying efficiencies of around 50% for Zn and Pb in 90 days, although for Cu and Mn these were smaller, namely of 28 and 14% respectively. These results show that phytoremediation of mine tailings is possible through grass planting that was able to remove the heavy metals. Index Terms—La Concha, México, phytoremediation, ryegrass, heavy metals. I. INTRODUCTION Environmental pollution caused by mining activities is a widespread problem throughout the world, which has negative consequences to human beings health, though largely to the environment. In México, the mining industry contributes with the 4.9% of the Gross Domestic Product [1]. Nevertheless this industry produces a considerably adverse environmental impact through each single production step: exploration, chemical and physical treatments affecting the soils during operations often have irreversible effects in soil properties, causing frequently its infertility, as well as inducing an important decrease in biodiversity [2], [3]. Furthermore, mining wastes contain high quantities of heavy metals that should be treated to avoid health risks to exposed populations. Taxco mines in the State of Guerrero, México are among the most important producers of silver ever since colonial times, but in the XX century they also became important Manuscript received April 28, 2014; revised July 17, 2014. This project was supported by the Universidad Autónoma Metropolitana, Azcapotzalco. V. Mugica-Alvarez and V. Domínguez-Soria are with the Department of Basic Sciences, Universidad Autónoma Metropolitana-Azcapotzalco, México (e-mail: vma@correo.azc.uam.mx, vdds@correo.azc.uam.mx). V. Cortés-Jiménez is with the Universidad Autónoma Metropolitana- Azcapotzalco (e-mail: lizvero@gmail.com). M. Vaca-Mier is with the Department of Energy, Universidad Autónoma Metropolitana-Azcapotzalco, México (e-mail: mvm@correo.azc.uam.mx). zinc and lead producers, consequently, tons of tailings from the benefit of minerals over several decades have been dumped nearby the producing mines, such as the sites known as La Concha and El Fraile, where less than 10% of the exposed surface has some kind of plant covering [4]. A brief visit to this site was enough to verify that at close quarters, to within than half a mile, there are dwellings and a secondary school. Next to and surrounding small agriculture lands and houses where their owners live, there are two large heaps of mine tailings: some of these inhabitants carry out their usual activities at distances less than 100 meters away from the said tailings. This means that people, animals and flora are highly exposed to high metal concentrations not only from wind and hydric dispersion, but also because the agricultural products grown at the sites could well contain metals; this situation represents a high risk to the population and the environment [5]. Phytoremediation is a biotechnological proposal that uses plants to stabilize, volatilize, extract or inactivate heavy metals and metalloids from polluted sites, reducing environmental risks; this is a cost-benefit technology, which is more attractive when compared to others that require intensive earth moving and expensive equipment [3], [6]. Phytoextraction is one of the mechanisms of phytoremediation that uptakes metals through the roots and to accumulate them subsequently in leaves and stems. Phytoremediation revegetates first polluted sites creating thus a plant covering that diminishes further dispersion of polluted dust through wind or water erosion [7], [8]. Phytoremediation is conducted taking advantage of native plants that tolerate the site‟s high pollution [9]. Nevertheless, it is necessary to make a study in the area to determine the feasibility of phytoremediation of such native plants, which should be grown off-site and then transplanted into the polluted ground and subsequently conserved [10]. Other alternative is the use of resistant species that can grow quickly, which apart from extracting metals can form a vegetal coverage to prevent soil erosion and dispersion. This is the case of grasses capable of growing in many places with different adverse climate conditions, having massive and deep root systems, examples of which are the vetiver grass (Vetiveria zizanioides) [11], tropical grass (Brachiaria brizantha) [12], smilo grass (Piptatherum miliaceum) [13], Italian ryegrass (Lolium multiflorium) [14], (Zhang, 2005) and English ryegrass (Lolium perenne) [15]. Despite the studies mentioned the use of grasses has not been widely recognized or investigated in detail Therefore, the aim of this paper is the application of phytoremediation at La Concha mine tailings using Italian ryegrass (Lolium multiflorum) in order to provide a green coverage that reduces the dispersion of polluted soil and Phytoremediation of Mine Tailings Using Lolium Multiflorum Violeta Mugica-Alvarez, Verónica Cortés-Jiménez, Mabel Vaca-Mier, and Victor Domínguez-Soria International Journal of Environmental Science and Development, Vol. 6, No. 4, April 2015 246 DOI: 10.7763/IJESD.2015.V6.599