Effects of vegetations on the removal of contaminants in aquatic environments: A review

This paper reviews the removal of contaminants including nutrients,metals and organic pollutants by vegetations in aquatic environments.The removal efficiencies are considered with respect to 16,19 and 14 kinds of different aquatic plants,respectively in three tables.Due to different characteristics,the removal effects of plants on contaminants from the overlying water differ greatly.The vegetation can improve the water quality mainly through two ways:(1)to adsorb and absorb pollutants from water,(2)to prevent pollutants from releasing from sediment.The contaminant removal mechanisms of vegetations and related physical,chemical and biological effects are discussed.The effects of vegetations on the contaminant removal are found to depend on the environmental conditions,the number and the type of plants,the nature and the chemical structure of the pollutants.In addition,the contaminant release and removal by vegetations under hydrodynamic conditions is specially addressed.Further research directions are suggested.