Phytoremediation of heavy metal contaminated soil by selection of plant species

摘要

Phytoremediation is an effective and promising solution to remediate polluted soils.This paper evaluates Solanum nigrum L.for its hyperaccumulative characteristics in mixed heavy metal contaminated soil in greenhouse pot trial and different Cd concentrations in hydroponic setup.Pot experiment showed preferential Zn uptake in all parts of the plant,concentration in stems ＞ leaves ＞ roots ＞fruits,followed by Pb and Cd.In hydroponic setup,Solanum nigrum L showed clear signs of stress with increases in Cd concentration in solution.It showed reduction in shoot biomass,but root biomass and root length were not affected.Increase in Cd uptake in stems and leaves was evidenced when exposing up to 50 μmol/L Cd concentration,then decline.On the contrary,Cd in root remained high indicating its greater tolerance.Result also confirms that Solanum nigrum L is effective in Cd remediation in soil and water due to the much larger fibrous root system covered with extremely large surface areas.