Skip to main content

Key Roles of Relativity in Hg Biogeochemical Transformations


EMSL Project ID
49868

Abstract

Mercury (Hg) is a toxic element that is interconverted among various chemical forms and transported throughout the environment through both biotic and abiotic processes. Mercury can be methylated by anaerobic microorganisms to form methylmercury (MeHg), which bioaccumulates in the food web, endangering humans and other biota. Conversely, other bacteria possessing bacterial resistance genes can demethylate methylmercury and reduce Hg(II) to elemental Hg(0). A primary goal of the DOE-funded "Biogeochemical Transformations at Critical Interfaces" Science Focus Area (SFA) project at Oak Ridge National Laboratory is to determine the fundamental mechanisms and environmental factors that control Hg biogeochemical transformations at critical interfaces in terrestrial and aquatic ecosystems. Task 4 of the SFA is primarily concerned with (bio)chemical Hg transformations at the molecular scale. The chemical properties of heavy elements such as Hg are known to be strongly influenced by relativistic effects. Thus, in this work we propose to leverage EMSL resources to carry out relativistic quantum mechanical calculations on the Cascade supercomputer to investigate the detailed molecular mechanisms of mercury methylation, enzymatic and photochemical demethylation and other chemical transformations.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2017-10-01
End Date
2018-09-30
Status
Closed

Team

Principal Investigator

Jerry Parks
Institution
Oak Ridge National Laboratory

Co-Investigator(s)

Jeremy Smith
Institution
Oak Ridge National Laboratory

Team Members

Peng Lian
Institution
Oak Ridge National Laboratory

Related Publications

Kanzler C.R., P. Lian, E.L. Trainer, X. Yang, N. Govind, J.M. Parks, and A.M. Graham. 2018. "Emerging Investigator Series: Methylmercury Speciation and Dimethylmercury Production in Sulfidic Solutions." Environmental Science Processes & Impacts 20, no. 4:584-594. PNNL-SA-130738. doi:10.1039/C7EM00533D