Role of microbial diversity for sustainable pyrite oxidation control in acid and metalliferous drainage prevention

Publication date: Available online 18 February 2020Source: Journal of Hazardous MaterialsAuthor(s): Omy T. Ogbughalu, Sotirios Vasileiadis, Russell C. Schumann, Andrea R. Gerson, Jun Li, Roger St. C. Smart, Michael D. ShortAbstractAcid and metalliferous drainage (AMD) remains a challenging issue for the mining sector. AMD management strategies have attempted to shift from treatment of acid leachates post-generation to more sustainable at-source prevention. Here, the efficacy of microbial–geochemical at-source control approach was investigated over a period of 84 weeks. Diverse microbial communities were stimulated using organic carbon amendment in a simulated silicate-containing sulfidic mine waste rock environment. Mineral waste in the unamended leach system generated AMD quickly and throughout the study, with known lithotrophic iron- and sulfur-oxidising microbes dominating column communities. The organic-amended mineral waste column showed suppressed metal dissolution and AMD generation. Molecular DNA-based next generation sequencing confirmed a less diverse lithotrophic community in the acid-producing control, with a more diverse microbial community under organic amendment comprising organotrophic iron/sulfur-reducers, autotrophs, hydrogenotrophs and heterotrophs. Time-series multivariate statistical analyses displayed distinct ecological patterns in microbial diversity between AMD- and non-AMD-environments. Focused ion beam-TEM micrographs and elemental mapping showed ...
Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research