| ACKNOWLEDGEMENTS | 第1-10页 |
| LIST OF TABLES | 第10-11页 |
| LIST OF FIGURES | 第11-12页 |
| ABSTRACT | 第12-14页 |
| ABSTRACT(IN CHINESE) | 第14-16页 |
| CHAPTER 1 Introduction | 第16-21页 |
| ·Research problem | 第16-17页 |
| ·Research objectives | 第17-19页 |
| ·Hypothesis | 第19-21页 |
| CHAPTER 2 Literature Review | 第21-34页 |
| ·Heavy metal toxicity in plants | 第21-28页 |
| ·Chromium in the environment | 第21-22页 |
| ·Sources and phytotoxic effects of Cr | 第22-23页 |
| ·Chromium uptake,translocation and accumulation in plants | 第23-24页 |
| ·Cadmium and phytotoxicity | 第24-26页 |
| ·Lead and phytotoxicity | 第26-27页 |
| ·Copper and phytotoxicity | 第27-28页 |
| ·Remediation of metal polluted soil | 第28-29页 |
| ·Phytoextraction | 第29-32页 |
| ·Natural or continuous phytoextraction using hyperaccumulators | 第30-31页 |
| ·Artificial or chemically enhanced phytoextraction using chelating agents | 第31-32页 |
| ·Wetland plants | 第32页 |
| ·Cattails | 第32-34页 |
| CHAPTER 3 Evaluation of T.angustifolia for Cr toxicity tolerance and its possible role in phytoremediation | 第34-45页 |
| ·Introduction | 第34-37页 |
| ·Materials and methods | 第37-38页 |
| ·Results | 第38-43页 |
| ·Plant height and biomass | 第38-39页 |
| ·SOD,POD activities and MDA content | 第39-42页 |
| ·Four microelement concentrations | 第42-43页 |
| ·Correlations between Cr and four microelements | 第43页 |
| ·Discussion | 第43-45页 |
| CHAPTER 4 Comparison of EDTA and citric acid- enhanced phytoextraction of heavy metals in artificially metal contaminated soil by T.angustifolia | 第45-62页 |
| ·Introduction | 第46-48页 |
| ·Materials and methods | 第48-51页 |
| ·Soil collection and artificial heavy metal contamination | 第48-49页 |
| ·Plant materials and chelator treatments | 第49-50页 |
| ·Sampling and measurements | 第50页 |
| ·Soil metal dissolution and as affected by chelators | 第50页 |
| ·Statistical analysis | 第50-51页 |
| ·Results | 第51-59页 |
| ·Effect of chelator addition on plant biomass of T.angustifolia | 第51页 |
| ·Effect of chelators on tissue metal concentration of T.angustifolia plants | 第51-57页 |
| ·Effect of chelators on metal accumulation by plants | 第57页 |
| ·Effects of chelator addition on metal solubility in soil | 第57-59页 |
| ·Discussion | 第59-62页 |
| References | 第62-74页 |
