Speaker
Description
Mercury methylation is a microbially mediated process that occurs in anaerobic soils, sediments, and at the water-sediment interface. Sulfur-reducing bacteria (SRB) uptake substrates, namely sulfate and dissolved organic carbon for growth, and transform inorganic mercury into methylmercury. Methylmercury is the most abundant and toxic organic mercury compound that bio-accumulates in tissues and bio-magnifies in the food chain. It is a neurotoxin that is a threat to all trophic levels and all stages of human life.
We present a model of the mercury methylation process that considers the governing chemical reactions; the production of methylmercury by SRB and the inhibition by sulfide, the product of the redox reaction that supports SRB proliferation, at high enough concentrations. In a first study, the model is studied in a chemostat setting. We perform model analysis and validation, and numerical simulation experiments to explore the system dynamics.
