TY - JOUR
T1 - Physical, chemical, and microbiological characterization of Kettara Mine Tailings, Morocco
AU - Benidire, Leila
AU - Pereira, Sofia I. A.
AU - Loqman , Souad
AU - Castro, Paula M. L.
AU - Boularbah, Ali
N1 - Funding Information:
This study was financially supported by the Convention de coopération CNRST-Morocco/FCT-Portugal, Centre National de Recherche Scientifique et Techniques [grant no. PPR 22/2015] and the project Phy2Sudoe—Advancing in the application of innovative phytomanagement strategies in contaminated areas of the SUDOE space (SOE4/P5/E1021), funded by the European Regional Development Fund (European Commission) through the V Interreg Sudoe Programme.
Funding Information:
The authors would like to thank the scientific collaboration of Fundação Ciência e Tecnologia (FCT) project UIDB/50016/2020. The authors would also thank to T. Hogg for correcting the English of this paper.
Publisher Copyright:
© 2022 by the authors.
PY - 2022/3
Y1 - 2022/3
N2 - The mining industry is of major importance to Morocco’s economy. However, the abandoned pyritic mines are a source of potentially toxic elements that can cause the disruption of the surrounding ecosystems, constituting a huge threat to wellbeing and human health. The present study aimed to analyze the physical and chemical characteristics of different types of tailings and to investigate the microbial populations of acidophilic bacteria involved in the oxidation of pyrite. Coarse and fine tailings collected from different zones of the mine (dike and pond) at two different depths (oxidized and non-oxidized residues) were analyzed for their pH, electrical conductivity, total organic carbon, total nitrogen, available P, major elements, and pseudo-total metal concentrations. The abundance of acidophilic bacteria was determined, and some acidophilic bacterial strains were isolated and tested for their metal tolerance. Tailings showed a pH ≈ 2, very low nutritional content, and high concentrations of Cu, As, Zn, and Pb, which were higher in the non-oxidized samples. The microbial counts of iron- and sulfur-oxidizing bacteria were higher than heterotrophic bacteria, with the highest numbers detected in the oxidized fine tailings. The five acidophilic bacteria isolated from the tailings were affiliated to genera Alicyclobacillus and Sulfobacillus, commonly found in this kind of environment.
AB - The mining industry is of major importance to Morocco’s economy. However, the abandoned pyritic mines are a source of potentially toxic elements that can cause the disruption of the surrounding ecosystems, constituting a huge threat to wellbeing and human health. The present study aimed to analyze the physical and chemical characteristics of different types of tailings and to investigate the microbial populations of acidophilic bacteria involved in the oxidation of pyrite. Coarse and fine tailings collected from different zones of the mine (dike and pond) at two different depths (oxidized and non-oxidized residues) were analyzed for their pH, electrical conductivity, total organic carbon, total nitrogen, available P, major elements, and pseudo-total metal concentrations. The abundance of acidophilic bacteria was determined, and some acidophilic bacterial strains were isolated and tested for their metal tolerance. Tailings showed a pH ≈ 2, very low nutritional content, and high concentrations of Cu, As, Zn, and Pb, which were higher in the non-oxidized samples. The microbial counts of iron- and sulfur-oxidizing bacteria were higher than heterotrophic bacteria, with the highest numbers detected in the oxidized fine tailings. The five acidophilic bacteria isolated from the tailings were affiliated to genera Alicyclobacillus and Sulfobacillus, commonly found in this kind of environment.
KW - Acid mine drainage
KW - Acidophilic bacteria
KW - Metals
KW - Runoff waters
UR - https://www.scopus.com/pages/publications/85146055832
U2 - 10.3390/soilsystems6010023
DO - 10.3390/soilsystems6010023
M3 - Article
SN - 2571-8789
VL - 6
JO - Soil Systems
JF - Soil Systems
IS - 1
M1 - 23
ER -