The Role of Mercury Chemical Speciation in Sediment Contamination

Published: 1/1/2018

Chemical speciation is defined as the determination of the individual concentrations of the various forms of an element that collectively make up the total concentration of that element.

Determining chemical speciation for sites contaminated with mercury can aid the remediation process. The transformations of inorganic mercury and methylmercury in contaminated sediments are influenced by chemical speciation and environmental conditions. For example, biomagnification in aquatic food webs occurs almost exclusively as mono-methyl mercury. The environmental conditions (e.g. primary productivity and redox conditions) vary substantially among sites and require careful consideration. It is also important to note that the total mercury concentration influences methylmercury production, likely by a control of the concentration of bioavailable inorganic mercury species. For these reasons, measurement of methylmercury concentration and solubility is advised for improved risk assessment of mercury-contaminated sediments.