ABSTRACT
The influx of heavy metal contaminants and pollutants into wetlands and aquatic systems from both natural and anthropogenic sources can be delivered by either eolian, fluvial, or tidal sources. Once within a wetland or aquatic environment, the ability of a metal to be transported depends on a range of abiotic and biotic biogeochemical processes, including adsorption onto and desorption from mineral surfaces; precipitation and coprecipitation; dissolution of minerals; and interaction with microbes, algae and plants. Oxidation state, the formation of oxyanions, sorption to the particulate or sediments, complexation with organic matter, precipitation, and interaction with microorganisms are processes governing the availability or toxicity of heavy metals in wetlands and aquatic systems. Some heavy metals, if present in the environment at excessive concentrations, can be toxic to aquatic organisms and inhibit the activity or role of microbes in key biogeochemical processes in wetlands.
