Uptake of Pb, Zn and Cu by roots and shoots of fast growing plants grown in contaminated soil in Vietnam

The phytoremediation of soil contaminated with lead (Pb), zinc (Zn) and copper (Cu) from industrial wastewater discharge in a farming village near Hanoi City was investigated. The first growing plant species tested were the Spanish needle, water primrose, common willow herb, and water spinach. Uptake by roots and shoots per unit land area for each species was calculated and compared. The uptake of the heavy metals per unit area was higher in shoots than in roots for each plant species and was affected by the higher biomass production of the shoots. For the roots, the uptake did not differ by species, but did differ by heavy metal. For the shoots, the uptake differed by both plant species and heavy metal with the common willow herb having higher Pb and Zn uptake compared to those of the other three species. For the common willow herb, the uptake of heavy metal was in order of Pb > Zn > Cu. The results indicate that common willow herb has a superior phytoremediation capacity among the plants tested, particularly for the uptake of Pb.   Key words: Plant biomass, farming village, industrial wastewater, phytoremediation.