Kinetics of Iron Uptake by Wetland Plants

Abstract

The aim of this study was to assess the kinetics of Fe removal by broad-leaved cattail, soft stem bulrush, soft rush and wool grass plants from contaminated wastewater under laboratory conditions. The approach used was based on a first order kinetic model which allowed for the evaluation of the specific metal uptake rate and the maximum accumulation of the metal in each plant species. The results showed that the model is capable of predicting the experimental data with relatively high confidence (R² = 0.98). The specific Fe uptake rate and the maximum amount of Fe that can accumulate in each plant species were affected by the initial Fe concentration in the wastewater and the plant species. As the initial concentration of Fe in the water increased, the specific Fe uptake rate of each species decreased with the exception of broad-leaved cattail. Soft stem bulrush displayed the highest specific Fe uptake rates followed by soft rush, cattail and wool grass. The maximum amount of Fe that accumulated in each species also increased as the initial Fe concentration in the wastewater increased. The results showed that soft stem bulrush plants would accumulate the highest amount of Fe in their tissues followed by broad-leaved cattail, wool grass and soft rush.