Impact of bacterial activities on release and speciation of heavy metals in anaerobic contaminated sediments

摘要

In this work, the impacts of autochtonous microorganisms on the dissolution and the speciation of heavy metals in anaerobic sediments were studied. Results obtained during the incubation of river sediments under anaerobic conditions indicated that metal solubilisation was correlated to microbial activity. In particular, Fe and Mn speciation confirmed a Fe and Mn reducing bacteria's activity. By reducing Fe and Mn oxides, these microorganisms contributed to the dissolution of their associated heavy metals (Co, Cu, Ni) leading to changes in the speciation of these metals in the sediments. Furthermore, sulphate-reducing bacteria were responsible for sulphide formation, leading to the formation of iron sulphides.