TITLE:
Qualitative Assessment of the Biogeochemical Reactivity of Sabodala Mine Tailings by Iron- and Sulphur-Oxidizing Bacteria
AUTHORS:
Maguatte Ndiaye, Mor Diop, Babacar Diouf, Tidiane Diop
KEYWORDS:
Biogeochemical Reactivity, Sulfur Cycle, Sulfur-Oxidizing Bacteria, Iron-Oxidizing Bacteria
JOURNAL NAME:
International Journal of Geosciences,
Vol.16 No.10,
October
15,
2025
ABSTRACT: The reactivity of sulphide mine tailings is generally only considered from a geochemical point of view. However, the biological aspect plays an important role in natural cycles containing carbon and sulphur. Metal mobility in mine tailings is often controlled by sulphides. Chemical reactions or bacterial processes can promote sulphide alteration followed by heavy metal leaching. The aim of the present study is to conduct a qualitative assessment of the biogeochemical reactivity of Sabodala mine tailings. The qualitative assessment in shake flasks consists of a double test: a biotic test containing a mixture of a mass of mine tailings and a substrate with an initial pH adjusted according to the targeted bacterial population, and an abiotic or control test containing the same complete culture medium with sterilized tailings. Following incubation on a rotary shaker, the electrochemical parameters (pH and Oxidation-Reduction Potential (ORP)) of the biotic and abiotic tests were monitored over time. The results of this study show that the activities of iron-oxidizing and sulphur-bacteria were not detected in the Sabodala tailings, even though they can survive in these environments. In other words, the absence of these natural occurrences protects the mining environment from sulphide oxidation, i.e., from the effects of Acid Mine Drainage (AMD).