The effect of soil types on the phytoremediation of heavy metals by Phragmites australis

Abstract

The remediation of heavy metals from contaminated sites by the application of phytoextraction is proving to be efficient and cost-effective. A pot experiment was conducted to ascertain the effect of soil types (sand, loam and clay) in the remediation of copper (Cu), chromium (Cr) and mercury (Hg) using Phragmites australis. The results obtained throughout 60 days of plant growth showed that the copper absorption in the roots of the plant in sandy, loamy and clayey soils was 47, 79.1 and 96 mg/kg, respectively. Chromium absorption in the roots of the plant in sandy, loamy and clayey soils was 136, 180 and 353 mg/kg, respectively, while mercury absorption in sand, loam and clay was 11.7, 14.8 and 19.3 mg/kg. The translocation factor for all metals in the three soil types was less than 1; however, the bioaccumulation factor in all cases was more than 1. The study concluded that the accumulation of chromium in the tissues of the plant was more pronounced than those of copper and mercury. Clayey soil proved to be the favourable soil required for the effective remediation of the metals into the tissues of a plant.