Micronutrient and heavy metal concentrations observed in natural wetland macrophytes in Arizona

Abstract

The use of macrophytes for the treatment of wastewater in constructed wetlands has caused concern over the possible concentration of elements within plant tissues. To better understand the potential of constructed wetland systems for adverse impacts, research was conducted to determine ranges at which micronutrients and heavy metals naturally exist in the root, shoot and leaf tissues of wetland plants in southern Arizona. Lemna sp., Anemopsis californica and Scirpus americanus concentrated the highest levels of micronutrients and heavy metals. Leaves of tree and shrub species usually had the lowest micronutrient and heavy metal concentrations of the plants analyzed in this study. Root tissues generally had higher concentrations of most elements, although elevated concentrations of micronutrients and heavy metals were found in the shoots of Typha domingensis and the leaf tissues of Anemopsis californica.