Removal of heavy metals (Pb²⁺, Cu²⁺ and Cr³⁺) from aqueous solutions using five plants materials

Abstract

The hazardous ill effects of heavy metals on the environment and public health is a matter of serious concern. Biosorption is emerging as a sustainable effective technology.  Heavy metals in water resources are one of the most important environmental problems of countries. The intensification of industrial activity and environmental stress greatly contributes to the significant rise of heavy metal pollution in water resources making threats on terrestrial and aquatic life. The toxicity of metal pollution is slow and interminable, as these metal ions are non bio-degradable. The aim of this study was to investigate the removal of heavy metals (Pb²⁺, Cu²⁺ and Cr³⁺) using five plants materials. These materials were used as sorbent for the removal of Pb, Cu and Cr ions from aqueous media. The five plants were collected different region in Ardabil province and after being dried, were cut into small pieces of size 5 mm. The materials were washed with distilled water, filtered and finally dried overnight at 60°C. They were homogenized to mesh 100 in a mortar and bolter and subsequently used for adsorption experiments. Adsorption studies were performed by batch experiments as a function of process parameters (such as sorption time and pH). Freundlich model fitted best with the experimental equilibrium data among the all tasted adsorption isotherm models. Experimental results showed that the best pH for adsorption was 4 and time was 60 min. This study also showed that absorbent prepared from Arnebia linearifolia and Artemisia fragrans species were suitable adsorbent to remove the Pb and Cr heavy metal ions.

Key words: Plant material, heavy metals, adsorption, removal of metals, adsorption isotherm.