| ACKNOWLEDGEMENTS | 第4-16页 |
| List of Abbreviations | 第16-18页 |
| ABSTRACT | 第18-20页 |
| 摘要 | 第21-23页 |
| CHAPTER Ⅰ Research background and review of literature | 第23-61页 |
| 1.1 Research background | 第23-24页 |
| 1.2 Presence of heavy metals in the environment and their health effects | 第24-25页 |
| 1.3 Sources of contaminants | 第25-26页 |
| 1.3.1 Airborne sources | 第25页 |
| 1.3.2 Process solid wastes | 第25-26页 |
| 1.3.3 Sludges | 第26页 |
| 1.4 Heavy metals pollution in China | 第26-27页 |
| 1.5 Cadmium | 第27-33页 |
| 1.5.1 Chemical properties of cadmium | 第28页 |
| 1.5.2 Isotopes | 第28页 |
| 1.5.3 Cadmium in China | 第28-29页 |
| 1.5.4 Cadmium in soil | 第29-31页 |
| 1.5.5 Factor affecting cadmium in soil | 第31-32页 |
| 1.5.6 Cadmium in plants | 第32-33页 |
| 1.6 Lead | 第33-40页 |
| 1.6.1 Chemical properties of lead | 第33-34页 |
| 1.6.2 Isotopes | 第34页 |
| 1.6.3 Lead in China | 第34-35页 |
| 1.6.4 Lead in soil | 第35-36页 |
| 1.6.5 Factor affecting lead in soil | 第36-38页 |
| 1.6.6 Lead in plants | 第38-40页 |
| 1.7 Remediation technologies | 第40-41页 |
| 1.8 Passivators | 第41-57页 |
| 1.8.1 Mechanism of passivators | 第42-44页 |
| 1.8.2 Biochar | 第44-49页 |
| 1.8.3 Slag | 第49-54页 |
| 1.8.4 Ferrous manganese ore | 第54-57页 |
| 1.9 Research Gap | 第57-58页 |
| 1.10 Specific objectives | 第58-61页 |
| Chapter Ⅱ Comparative effects of biochar, slag and ferrous-Mn ore on lead and cadmium immobilization in soil | 第61-76页 |
| 1.11 Introduction | 第61-62页 |
| 1.12 Materials and methods | 第62-65页 |
| 1.12.1 Characterization of red brown soil | 第62-63页 |
| 1.12.2 Incubation | 第63-64页 |
| 1.12.3 Sequential extraction | 第64页 |
| 1.12.4 Toxicity characteristic leaching procedure (TCLP) | 第64页 |
| 1.12.5 CaCl_2 single extraction | 第64-65页 |
| 1.12.6 Ammonium nitrate | 第65页 |
| 1.12.7 Statistical analysis | 第65页 |
| 1.13 Results | 第65-71页 |
| 1.13.1 Soil EC and pH | 第65-66页 |
| 1.13.2 BCR fractions of lead and cadmium | 第66-68页 |
| 1.13.3 TCLP-extractable cadmium and lead | 第68-70页 |
| 1.13.4 NH_4NO_3 and CaCl_2-extractable lead and cadmium | 第70-71页 |
| 1.14 Discussion | 第71-75页 |
| 1.15 Conclusion | 第75-76页 |
| Chapter Ⅲ Leaching behaviour of Pb and Cd and transformation of their speciation in co-contaminated soilreceiving different passivators | 第76-95页 |
| 1.16 Introduction | 第76-77页 |
| 1.17 Materials and methods | 第77-80页 |
| 1.17.1 Preparation of soil | 第77-78页 |
| 1.17.2 Soil column construction | 第78-79页 |
| 1.17.3 Analytical Analysis | 第79-80页 |
| 1.18 Results | 第80-90页 |
| 1.18.1 Total metals contents of corresponding soil column layers | 第80页 |
| 1.18.2 pH and EC of corresponding soil column layers | 第80-82页 |
| 1.18.3 Fractionation of Pb and Cd of corresponding soil column layers | 第82-85页 |
| 1.18.4 CaCl_2 extractable Pb and Cd of corresponding soil column layers | 第85页 |
| 1.18.5 TCLP extractable Pb and Cd of corresponding soil column layers | 第85-88页 |
| 1.18.6 pH of the leachate collected | 第88页 |
| 1.18.7 Total metal contents of leachate | 第88页 |
| 1.18.8 Adhesion efficiency of passivators | 第88-90页 |
| 1.19 Discussion | 第90-94页 |
| 1.20 Conclusion | 第94-95页 |
| Chapter Ⅳ Passivators application improving physical, chemical and microbial biomass properties in Pb andCd co-contaminated acidic soils | 第95-113页 |
| 1.21 Introduction | 第95-97页 |
| 1.22 Materials and methods | 第97-101页 |
| 1.22.1 Description of study area | 第97-98页 |
| 1.22.2 Characterization of passivators analysis by using SEM, XRD, and FTIRspectroscopy | 第98页 |
| 1.22.3 Experimental layout | 第98页 |
| 1.22.4 Laboratory analysis | 第98-101页 |
| 1.22.5 Analysis of data | 第101页 |
| 1.23 Results | 第101-108页 |
| 1.23.1 Passivators characteristics | 第101-104页 |
| 1.23.2 Passivators changes the Pb and Cd-induced inhibition of soil physical properties | 第104-105页 |
| 1.23.3 Passivators changes soil chemical properties under Pb and Cd stress | 第105页 |
| 1.23.4 Passivators changes soil biological properties under Pb and Cd stress | 第105-108页 |
| 1.24 Discussion | 第108-111页 |
| 1.25 Conclusion | 第111-113页 |
| Chapter Ⅴ Lead and cadmium mobility, uptake and anti-oxidative response of sesame (Sesamum Indicum L.)under biochar, slag and ferrous manganese ore as amendments | 第113-142页 |
| 1.26 Introduction | 第113-115页 |
| 1.27 Materials and methods | 第115-119页 |
| 1.27.1 Characterization soil and passivators | 第115页 |
| 1.27.2 Experimental design, plant sampling and analysis | 第115-117页 |
| 1.27.3 Extraction and assay of antioxidant enzymes | 第117页 |
| 1.27.4 Extraction and assessment of glutathione (GSH) contents | 第117页 |
| 1.27.5 Assessment of photosynthetic pigments, soluble protein, and proline contents | 第117页 |
| 1.27.6 Estimation of H_2O_2, MDA and electrolyte leakage | 第117页 |
| 1.27.7 Analysis of relative expression of genes by using RT-qPCR | 第117-118页 |
| 1.27.8 Soil and plant nutrients | 第118页 |
| 1.27.9 Soil laboratory analysis | 第118-119页 |
| 1.27.10 Statistical analysis | 第119页 |
| 1.28 Results | 第119-134页 |
| 1.28.1 Passivators enhances the Pb and Cd-induced inhibition of sesame seedling growthand photosynthesis pigments | 第119-120页 |
| 1.28.2 Passivators maintains the membrane integrity by suppressing the H_2O_2, MDAcontent and EL under Pb and Cd stress | 第120页 |
| 1.28.3 Passivators efficiently downregulate the activities of enzymatic and non-enzymatic antioxidant | 第120-123页 |
| 1.28.4 Impact of Passivators, Pb and Cd on genes expression | 第123页 |
| 1.28.5 Effect of passivators on soluble protein and proline content under Pb and Cd stress | 第123-127页 |
| 1.28.6 Passivators application improves soil and plant nutrients and suppresses Pb andCd uptake | 第127-128页 |
| 1.28.7 pH and EC of soll | 第128页 |
| 1.28.8 SBET, CaCl_2 and TCLP extractable Pb and Cd of soil | 第128-134页 |
| 1.29 Discussion | 第134-140页 |
| 1.30 Conclusion | 第140-142页 |
| Chapter Ⅵ Conclusions and future directions | 第142-146页 |
| 1.31 General conclusions | 第142-144页 |
| 1.32 Future perspectives | 第144-146页 |
| References | 第146-181页 |
| Publications arising from this dissertation | 第181页 |
