Phytoremediation and absorption isotherms of heavy metal ions by Convolvulus tricolor (CTC)

ABSTRACT

In recent years, use of plants for remediation of contaminated soils, especially removal of heavy metals, is considered. The current study tends to investigate the removal of lead and nickel ions by the Convolvulus tricolor (CTC), was grown for 30 days in different concentrations of lead and nickel ions. Then concentration of them in soil and different organs of the plant was measured by atomic absorption spectrometry.

The highest absorbed of them occurred in concentration 0.001N, which highest Pb²⁺ accumulation is in the aerial parts of the plant: leaf > stem > root and for Ni²+: root > stem > leaf. No ion was observed into the flowers and nickel ion absorption is more of lead ion in different plant organs of CTC.

The experimental isotherm data were investigated using isotherms of Langmuir, Freundlich, BET, Temkin and Dubinin–Radushkevich (DRK). The correlation coefficient for all of them is calculated that show the best correlation coefficient for Ni²⁺ adsorption is obtained BET model, whereas for Pb²⁺ adsorption in root is Freundlich model but for its leaf and stem is BET model. The results show, CTC is suitable for Pb²⁺ and Ni²⁺ and this technique is in-situ method, simple, and low cost.

KEYWORDS:

• phytoremediation
• contaminated soils
• heavy metal ions
• Convolvulus tricolor (CTC)
• absorption isotherm equations

Acknowledgment

I would like to thank from Doroud branch of Islamic Azad University, for providing me with all the necessary facilities for the research.