Anirban Basu

I am an isotope geochemist, with special interest in redox-sensitive metal isotopes. My research focuses on reduction-oxidation (redox) reactions that are critical to many aspects of chemistry involved in energy and environment. The molecular mechanisms of these reactions are relatively poorly understood, and in natural environments, they often require biological intervention to proceed at significant rates.

I develop the use of non-traditional stable isotope systems as indicators of biogeochemical processes in modern and ancient environments. Several redox-sensitive elements (Cr, U, Se, and Mo) show great promise as indicators of environmental cycling of metals, essential nutrients and radionuclides.

My research combines microbiology, geochemistry and hydrogeology; integrates laboratory experiments with field-scale investigations and aims to understand processes responsible for groundwater pollution, radioactive waste management, remediation of emerging contaminants such as tellurium, sustainable management of soils, past ocean chemistry, and the formation of economic ore and strategic metal deposits.

Conceptual model for bacterial uranium removal and associated changed in U isotope ratios.

The uranium reduction is occurring on the bacterial cells. This model suggests that the balance between uranium removal rate and the chemical communication between dissolved uranium and bacterial enzyme will control uranium isotope ratios (Basu et al., 2020, ES&T).

Drilling to collect samples from a roll-front uranium deposit, Rosita, Texas.

Currently, solution mining of roll-fronts accounts for about 50% of the global uranium mining. Solution mining leaves toxic uranium in the groundwater that must be cleaned up to minimize its environmental impact. My research develops isotopic tracers of migration of uranium in groundwater at the mine sites and detect natural remediation uranium.

References:

• Brown, ST, Basu , A, Ding , X, Christensen, JN & DePaolo, DJ 2018, 'Uranium isotope fractionation by abiotic reductive precipitation', Proceedings of the National Academy of Sciences of the United States of America, vol. 115, no. 35, pp. 8688-8693. https://doi.org/10.1073/pnas.1805234115
• Basu, A, Sanford, RA, Johnson, TM, Lundstrom, CC & Löffler, FE 2014, 'Uranium isotopic fractionation factors during U(VI) reduction by bacterial isolates', Geochimica et Cosmochimica Acta, vol. 136, pp. 100-113. https://doi.org/10.1016/j.gca.2014.02.041