In situ recovery of uranium — the microbial influence

In situ recovery (ISR) has become an increasingly utilized technology worldwide for the economical extraction of uranium (U). Microorganisms play a significant role in U mobilization/immobilization and have therefore been used for the bioremediation of U contaminated sites. In natural environments a wide range of microorganisms has the ability to oxidize or reduce U compounds as part of their metabolism. Hence, microbiota is very likely to play an important role at all stages of U ISR; however the effect of resident microbial communities subject to ISR has not been investigated. Therefore, this review focuses on the interactions between microorganisms and U and the possible effects this could have on ISR operations. Microorganisms may affect ISR in either a positive or negative way, e.g. assisting in U mobilization via the oxidation of U or immobilizing U by reducing it into an insoluble form. The use of native microbial communities to influence the mobilization/immobilization of U during ISR could help to increase U recovery rates or speed-up post-mining remediation.