Metal contaminant source, transport and fate in the environment and phytoremediation methods

Heavy metal pollution due to anthropogenic sources is on the rise causing great environmental and human health problems. Although remediation of metal contaminants can be via excavation or stabilization of the soil or sediments, these methods can be quite costly in the long run and it is not efficient for the small-scale removal of heavy metal contaminants. Phytoremediation is a fairly new and "green" technology, and with a focus on heavy metals as the contaminants in question, this method utilizes plants for in-situ reduction and/or removal of contaminants from soil, sediments and water. The process of phytoremediation is quite simple, and with the proper selection of plants and appropriate site conditions, the risk from these contaminants can be reduced and minimized over time. Phytoremediation is energy efficient, and an aesthetically pleasing method of remediating sites with low to moderate levels of contamination. The purpose of this paper is to provide a general review of metal contaminant source, transport and fate as well as current phytoremediation methods including their advantages and disadvantages, and the future directions in research using these methods.