Seed Germination and Seedling Growth of Five Plant Species for Assessing Potential Strategies to Stabilizing or Recovering Metals from Mine Tailings

Abstract

This study evaluated the seed germination and dry mass accumulation of five plant species (Brassica napus L., Brassica rapa L., Celosia cristata L., Tagetes erecta L., and Calendula officinalis L.) grown in five mine tailings collected from Zacatecas, Mexico. Sampled mines were El Bote, Noria de San Pantaleon, Noria de Angeles, Vetagrande, and El Bordo-El Lampotal, in which Pb (3.9–69.7 mg kg−1), As (0.7–26.2 mg kg−1), Hg (0.05–0.10 mg kg−1), and Au (0.01–0.02 mg kg−1) were detected. The most abundant elements at each mine site were as follows: Pb and Au (3.9 and 0.023 mg kg−1, respectively) for El Bote; As, Pb, and Hg (7.4, 6.1, and 0.10 mg kg−1, respectively) for the Noria de San Pantaleon; Pb, As, and Hg (69.7, 26.2, and 0.08 mg kg−1, respectively) for Noria de Angeles; Pb (20.8 mg kg−1) for Vetagrande; and Pb (5.3 mg kg−1) for El Bordo-El Lampotal. Both Noria de Angeles and Vetagrande mine tailings had high values of sodium, sulfates, and electrical conductivity, chemical properties that impaired seed germination and dry mass accumulation. Regardless the mining tailings, B. napus showed high seed germination (66 %), tolerance, growth, and total dry mass accumulation (0.041 g). Either B. napus or C. cristata has good potential for stabilizing or recovering metals from mine tailings.