Phytoremediation And Its EDTA-Enhanced Techniques For Mined Lands Contamination With Lead By Typha Orientalis Presl

There are about 474 metal mines in Hunan Province. Most of the tailings have been left without any management in these mines. It has become the main source of heavy metal contamination in the mining areas, which including soil substrates contaminated, soil texture destroyed, short of nutrient, ecological landscape destroyed, water pollution and biological diversity decrease. Work should do to restore the ecology on mined areas.Accumulation of lead in the different tissues of Typha orientalis P., a dominant plant species growing on the Yongzhou Pb/Zn/Cu mine tailings, Hu'nan Province, has been studied through a series of field investigations and hydroponic culture. The results of tissue analyses on the plants collected from this high lead environment determined that Typha orientalis P. had a strong accumulation of lead. The average lead concentrations in the leaves and roots dry matter were 619 mg/kg and 1233 mg/kg, respectively. The hydroponic culture results ulteriorly demonstrated the high- accumulating ability. The maximum Pb concentrations in the leaves and roots dry matter were 12413 mg/kg and 30508 mg/kg, respectively, at 300 mg/L Pb(NO3)2. We also studied the effects of EDTA on the accumulation of Pb by Typha orientalis P.. Adding more EDTA in the medium not only increased the amount of Pb taken up by plants but also speeded up the metal translocation from roots to leaves, as well as lowering Pb phytotoxicity, which resulted in increased IT value and plant fresh weight.The other aim of our research was to demonstrate how the presence of EDTA affects resistance of Typha orientalis P. to Pb and Pb-EDTA presence, and to show the chemical forms of Pb in it. The influence of Pb and Pb-EDTA on physiological and biochemical growth parameters was studied to elucidate the mechanism of lead resistance in Typha orientalis P.. The effects of EDTA ranging in concentration from 0.1 to 0.5 mmol/L, on the mechanism of accumulation under Pb2+ stress (range 0.15-0.3 mmol/L) in Typha orientalis P. grown hydroponically were investigated in order to offer a referenced evidence for an understanding of the mechanism by which EDTA relive the damage to plants by heavy metal and improve the phytoremediation efficiency of heavy metal-contaminated water. It can be seen in the presented research results that addition of the chelator with Pb limited metal phytotoxicity. The mean total chlorophyll concentration and protein content were increased with the addition of EDTA in Pb2+ solution. We also demonstrated a significant effect of EDTA on the...