Bioconcentration of heavy metals by three plant species growing in Golmarz wetland, in northwestern Iran: The plants antioxidant responses to metal pollutions

In the present study heavy metal contaminations in water and sediments of the Golmarz wetland in northwestern Iran were determined. Moreover, bio-monitoring of metal pollution in the aquatic ecosystem and evaluating the role of some plant species in bioaccumulation and remediation of heavy metals from the environment were performed. The metal(loid) concentrations in water, sediment and plant samples were measured by inductively coupled plasma-mass spectroscopy (ICP-MS). It was established that there was no metal contamination in water samples, but the sediments were highly contaminated by Se and As. Typha latifoila was able to accumulate large amount of Cd, Pb, Ni, and Zn in its root and the amount of its enrichment coefficient of root for the elements was more than 1. Due to its large biomass and its high potential in elements uptake, T. latifolia was a suitable species for metal's phytoremediation. Panicum maximum was capable to uptake and transporting Pb and Cd to its above-ground parts. Moreover, Scirpus lacustris showed good potential to accumulate of Cd and Pb in its root. The obtained results indicated that the activity of antioxidant enzymes and the amounts of phenol and flavonoids in three plant species were high in the most polluted sampling sites. Therefore, the plants try to adapt the existence of heavy metal by induction of their defense systems.