Bioavailability and Methylation Potential of Mercury Sulfides in Sediments
Abstract
In this project, we investigated the geochemical processes that control the bioavailability of mercury to methylating bacteria in contaminated sediments. The research tested the hypothesis that kinetically-limited mercury sulfide mineralization reactions, rather than equilibrium porewater chemistry, controls the concentration of bioavailable mercury to sediment bacteria that convert it to methylmercury, the form that bioaccumulates in food webs (Figure E.1). We studied the relationship between mercury speciation and biouptake/methylation in sediments, a relationship that remains poorly understood. The work focused specifically on the microbial methylation potential of nanoparticulate HgS in relation to bulk scale HgS and dissolved Hg-sulfide species. The aim was to establish a premise that links the age and chemical form of Hg in sediment porewater to the rate of MeHg formation. The kinetic data was incorporated in a conceptual model describing the fate of mercury.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2014
- Accession Number
- ADA619410
Entities
People
- Heileen Hsu-Kim
- Marc A Deshusses
Organizations
- Duke University