Professional Education

  • Ph.D., University of Rennes, France, Earth Sciences (Hydrogeology) (2016)
  • M.S., University of Rennes, France, Earth Sciences (2013)
  • B.A., University of Rennes, France, Earth Sciences (2011)

All Publications

  • Stratification of reactivity determines nitrate removal in groundwater. Proceedings of the National Academy of Sciences of the United States of America Kolbe, T. n., de Dreuzy, J. R., Abbott, B. W., Aquilina, L. n., Babey, T. n., Green, C. T., Fleckenstein, J. H., Labasque, T. n., Laverman, A. M., Marçais, J. n., Peiffer, S. n., Thomas, Z. n., Pinay, G. n. 2019


    Biogeochemical reactions occur unevenly in space and time, but this heterogeneity is often simplified as a linear average due to sparse data, especially in subsurface environments where access is limited. For example, little is known about the spatial variability of groundwater denitrification, an important process in removing nitrate originating from agriculture and land use conversion. Information about the rate, arrangement, and extent of denitrification is needed to determine sustainable limits of human activity and to predict recovery time frames. Here, we developed and validated a method for inferring the spatial organization of sequential biogeochemical reactions in an aquifer in France. We applied it to five other aquifers in different geological settings located in the United States and compared results among 44 locations across the six aquifers to assess the generality of reactivity trends. Of the sampling locations, 79% showed pronounced increases of reactivity with depth. This suggests that previous estimates of denitrification have underestimated the capacity of deep aquifers to remove nitrate, while overestimating nitrate removal in shallow flow paths. Oxygen and nitrate reduction likely increases with depth because there is relatively little organic carbon in agricultural soils and because excess nitrate input has depleted solid phase electron donors near the surface. Our findings explain the long-standing conundrum of why apparent reaction rates of oxygen in aquifers are typically smaller than those of nitrate, which is energetically less favorable. This stratified reactivity framework is promising for mapping vertical reactivity trends in aquifers, generating new understanding of subsurface ecosystems and their capacity to remove contaminants.

    View details for DOI 10.1073/pnas.1816892116

    View details for PubMedID 30692250

  • Inherent relevance of MRMT models to concentration variance and mixing-induced reactivity ADVANCES IN WATER RESOURCES Babey, T., de Dreuzy, J., Rapaport, A., Rojas-Palma, A. 2017; 110: 291–98
  • Spatiotemporal simulations of 2,4-D pesticide degradation by microorganisms in 3D soil-core experiments ECOLOGICAL MODELLING Babey, T., Vieuble-Gonod, L., Rapaport, A., Pinheiro, M., Garnier, P., de Dreuzy, J. 2017; 344: 48–61
  • From conservative to reactive transport under diffusion-controlled conditions WATER RESOURCES RESEARCH Babey, T., de Dreuzy, J., Ginn, T. R. 2016; 52 (5): 3685–3700
  • Multi-Rate Mass Transfer (MRMT) models for general diffusive porosity structures ADVANCES IN WATER RESOURCES Babey, T., de Dreuzy, J., Casenave, C. 2015; 76: 146–56
  • Influence of porosity structures on mixing-induced reactivity at chemical equilibrium in mobile/immobile Multi-Rate Mass Transfer (MRMT) and Multiple INteracting Continua (MINC) models WATER RESOURCES RESEARCH de Dreuzy, J., Rapaport, A., Babey, T., Harmand, J. 2013; 49 (12): 8511–30