Related Experiment Video
Updated: Jun 27, 2026

An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Importance of elemental mercury in lake sediments
1Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec H3C3J7, Canada.
Abstract:
Mercury (Hg) redox changes in sediments are poorly studied and understood, even though they potentially control Hg availability for methylation and can alter sediment-water Hg exchange. Elemental Hg (Hg(0)) concentrations in sediments of two Canadian Shield lakes were assessed by thermodesorption. Hg(0) concentrations in sediments varied between 6.3 and 60.3 pg g(-1) (wet weight) which represented 7.4-28.4% of total mercury (HgT) concentration. Hg(0) concentrations were similar in both lakes. Hg(0) was rapidly adsorbed on sediments in controlled adsorption experiments and surface sediments sampled in summer had a stronger affinity for Hg(0) than deeper sediments and sediments sampled in fall. This adsorption was positively correlated to organic matter content and negatively related to particle grain size, pH and oxygen concentration in overlying water. This study demonstrates that Hg(0) is a prevalent species in sediments, but not in porewater, because of the high sorptive capacity of sediments towards Hg(0). Its potential availability towards Hg methylating bacteria remains to be determined.
Related Concept Videos
Microbes and Other Elemental Cycles
The Periodic Table and Organismal Elements
Periodic Table Provides Information...
Deep Sea Microbial Ecology
Freshwater Microbial Ecology
Preparation of Samples for Electron Microscopy
Voltammetry: Overview
A voltammetric cell uses three electrodes: a working electrode, a reference electrode, and an auxiliary electrode. The redox reactions occur in the working...
