STUDY AND SELECT PLANTS FOR PHYTOREMEDIATION OF HEAVY METALS (Cr, Cu, Zn) CONTAMINATED SEDIMENT FROM TAN HOA – LO GOM CANAL

Abstract

The article presents first results of phytotechnology to remove heavy metals from dredged sediment in Tan Hoa-Lo Gom Canal, HCM City. Maize (Zea mays L.) and elephant grass (Pennisetum purpureum) were selected to assess the heavy metal absorption capacity. Total concentrations of Cr, Cu and Zn in dredged sediments were 2656 mg/kg, 1551 mg/kg, and 2463 mg/kg. After a growth period of 6 weeks, the heavy metals (Cr, Cu, Zn) concentrations were 456 mg/kg, 429 mg/kg and 1327 mg/kg in the maize, and 519 mg/kg, 458mg/kg and 1136 mg/kg in the elephant grass, respectively. After a growth period of 12 weeks, the heavy metals (Cr, Cu, Zn) concentrations were 584 mg/kg, 536 mg/kg and 1668 mg/kg in the maize root, respectively 697 mg/kg, 564 mg/kg and 1460 mg/kg in the elephant grass. Most of heavy metals (Cr, Cu and Zn) were accumulated in roots, 5.1÷130 times concentration higher than in shoots of maize and elephant grass. Results showed that these species could be used for phytotechnology of sediment/soil contaminated by Cr, Cu and Zn, with the minor risk of transferring toxic metals into the food chain.