Interaction of Elemental Mercury with Environmentally Relevant Surfaces

English Abstract:

Elemental Mercury (Hg(0)) is a toxic global pollutant with a tendency to bio-magnify and cause severe physiological impairments. Once released into the atmosphere, Mercury, has the ability to be transported over synoptic scales by global wind flows and contaminate sites geographically well separated from source regions. Of importance to the long range transport of mercury are terrestrial-atmospheric Hg exchange interactions and associated redox reactions of Mercury. Modelling attempts to characterize the global transport of mercury is limited by the lack of fundamental laboratory kinetic data on these redox interaction, in particular, heterogeneous reactions. The abundance of environmental aerosols and surfaces (natural and anthropogenic) in the troposphere can impact the speciation of Hg(0) (Mercury bound to particulate matter) and alter the kinetics of Mercury redox reactions. To this extent we present data on the interactions of gas phase Hg(0) on commonly found natural (Iron Oxides) and anthropogenic (Fly-Ash) nano-particulate surfaces at environmentally relevant conditions of Ozone, Irradiation and Humidity. We have employed the use of GC-MS (operating in SIM mode) to quantitatively monitor Hg(0) in our systems and performed phase and size characterizations of our solid phases using XRD and Nano-particle Tracking Analysis (NanoSight, Malvern). We will further discuss the possible implications of this on mercury transport mechanisms.