Lead and Chromium Biosorption by Pistia stratiotes Biomass

Abstract

Biosorption using biological materials has been extensively studied as a promising technology to contain the environmental impacts caused by heavy metals. Among the alternative biosorbents evaluated macrophytes shows high affinity by metal ions. In addition, this kind of material are from renewable sources, biodegradable and easy to grow, supporting wide ranges of pH and temperature. Therefore, theaim of this study is to evaluate the performance of macrophyte Pistia stratiotes in Cr³⁺ and Pb²⁺ removal.
Equilibrium isotherms data were fitted to Langmuir model and the maximum uptake capacities were 0.317 and 0.225 mmol.g^-1 for Cr³⁺ and Pb²⁺, respectively. In order to know the biosorption mechanism FT-IR analyses were performed for P. stratiotes before and after uptake of metal ions. The results showed different functional groups on the biomass surface and the ability of these groups bind with Cr⁺³ and Pb²⁺ ions in aqueous solution.