Table of Contents

CHAPTER 1 INTRODUCTION 1
1.1 Unintended consequences of shale gas operations: Environmental risk 1
1.1.1 Chemicals in Wastewater 9
1.1.2 Wastewater Leakage 12
1.2 Human Health Risk Assessment 13
1.2.1 Planning -Planning and Scoping process 13
1.2.2 Step 1 -Hazard Identification 14
1.2.3 Step 2 -Dose-Response Assessment 16
1.2.4 Step 3 -Exposure Assessment 19
1.2.5 Step 4 -Risk Characterization 20
1.2.6 Step 5 Sensitive Analysis 20

CHAPTER 2 MATHMATIC MODELS 22
2.1 Human Health Risk Assessment Model 23
2.2 Monte-Carlo Method 24

CHAPTER 3 RISK ASSESSMENT MODEL APPLICATION 25
3.1 Introduction 25
3.2 Method and materials 27
3.2.1 Initial data 27
3.2.2 Pollutant concentrations in environmental compartments 27
3.2.3 Probabilistic risk assessment 33
3.3 Results 36
3.3.1 Air inhalation risks 36
3.3.2 Surface soil exposure risks 44
3.4 Discussion 47
3.5 Conclusion 48

CHAPTER 4 FLOWBACK WATER TREATMENT 50
4.1 Research progress of heterogeneous Fenton catalyst for organic wastewater treatment 50
4.1.1 Research status of Fenton reaction 50
4.1.2 Performance study of heterogeneous Fenton catalyst 51
4.1.3 Conclusion 55
4.2 Study on fracturing flowback fluid treatment technology for shale gas in Yangzhou 56
4.2.1 Water quality characteristics of the flowback fluid in Yangzhou 56
4.2.2 Experiment design 56
4.2.3 Results and discussions57
4.2.4 Conclusions 63
4.3 Study on treatment of acidified waste liquid by process of neutralization/oxidation/flocculation 63
4.3.1 Experimental methods 64
4.3.2 Results and discussion 64
4.3.3 Conclusions 68
4.4 Advances in the treatment of organic wastewater with heterogeneous supported Fenton catalyst 68
4.4.1 Performance study of heterogeneous supported Fenton catalyst 69
4.4.2 Summary and prospect 73
4.5 Removal of scaling ions from catalytic oxidation and flocculation-treated fracking flowback fluids 74
4.5.1 Materials and Methods 75
4.5.2 Results and Discussion 77
4.5.3 Conclusions 81
4.6 Factors influencing the removal of boron from fracturing fluid flowback by chemical oxidative precipitation 82
4.6.1 Materials and Methods 83
4.6.2 Results and Discussion 85
4.6.3 Conclusions 91
4.7 Method for synergistic degradation treatment of polysaccharide-containing polymer wastewater by controllable ·OH radical 91
4.7.1 Background 91
4.7.2 Results 94
4.7.3 Conclusion 97
4.8 Integrated boron removal and flocculation process for treating fracturing wastewater 99
4.8.1 Background 99
4.8.2 Results 102
4.8.3 Conclusion 104
4.9 Method for preparing superfine calcium carbonate by treatment process of waste liquid in oilfield operations 104
4.9.1 Background 104
4.9.2 Results 106
4.9.3 Conclusion 107
4.10 Method for modified clay assisted microbial treatment of oil-gas field produced water with large amount of scale buildup 108
4.10.1 Background 108
4.10.2 Results 111
4.10.3 Conclusion 114

APPENDIX 116

REFERENCES 120