Hyperaccumulators of mercury in the industrial area of a PVC factory in Vlora (Albania)

Abstract

Contamination by heavy metals is one of the major threats to soil and water as well as human health. Much attention is being paid to metal-accumulating plants that may be used for the phytoremediation of contaminated soils. Some plants can accumulate remarkable levels of metals, 100-1000-fold the levels normally accumulated in most species. This study evaluated the potential of mercury accumulation of 17 plant species growing on contaminated sites in the ex-industrial area of the PVC Factory, Vlora, Albania. Plant roots, shoots and soil samples were collected and analyzed for the selected metal concentration values. The biological accumulation coefficient (BAC) was calculated to evaluate the potential use of plant species for phytoremediation purposes. The concentration of Hg in soils inside the contaminated area varied from 45-301 mg/kg-1. The concentration of Hg in plant shoots and roots varied from 0.1 to 12.9 mg/kg-1 and 0.1 to 4.2 mg/kg-1, respectively. Species Medicago sativa L. and Dittrichia viscosa (L.) W. Greuter were found to be the most suitable plants for phytoremediation of the site contaminated with mercury (BAC values varied from 30-10 percent, respectively). Considering the BAC values, none of the plant species was found to be a hyperaccumulator; however, plants with high BCF (metal concentration ratio of plant root to soil) and low BTC (metal concentration ratio of plant shoots to roots) have the potential for phytostabilization and phytoextraction. The results of this study can be used for the management and decontamination of soils with mercury using plant species having phytoremediation potential/characteristics.

Keywords

• hyperaccumulators
• mercury
• phytoremediation