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 Cu, Cr and Hg using Phragmites australis. The results obtained throughout 60days of the plant’s growth showed that Cu absorption in the roots of the plant in sandy, loamy and clayey soils was; 47 mg/kg, 79.1 mg/kg and 96 mg/kg respectively. Cr absorption in the roots of the plant in sandy, loamy and clayey soils was 136 mg/kg, 180 mg/kg and 353 mg/kg respectively whilst that of Hg absorption in sand, loam and clay were 11.7 mg/kg, 14. mg/kg 8 and 19.3 mg/kg. The translocation factor for all the metals in the three soil types was less than one, however, the Bioaccumulation Factor (BAF) in all cases were more than one. The study concluded that the accumulation of Cr in the tissues of the plant was more pronounced than Cu and Hg. Clayey soil proved to be the favourable soil required for the effective remediation of the metals into the tissues of the plant.