Ecotoxicological Diagnosis in the Tanning Industry (eBook)

Dr. Mwinyihija's current research interests include impact of salt to the terrestrial/aquatic environment as a pollutant of the tanning industr, recovery mechanisms of river sediment on pollution load, determination of particulate matter and its ecotoxicological potency in the environment, and dynamics of diffuse contamination.

Chapter 1: Introduction 17
1.1 Tanning Industry Perspective 17
1.2 Socio-Economic Importance of the Tanning Industry 18
1.3 Environmental Threats 18
1.4 Critical Pollutants Identified 18
1.5 Ecotoxicology and Diagnostic Trends 19
1.6 Bioavailabilty, Bioaccumulation and Biomagnification 21
1.7 Biochemical Assays for Diagnostic Purposes 22
1.7.1 Biosensors 22
1.8 Measurement of Biomass Activity 25
1.8.1 Dehydrogenase 25
1.8.2 Mode of Action for DHA 26
1.8.3 Application of the DHA Test 27
1.8.4 Limitation in Using DHA Test 27
1.8.5 Addressing the Limitations of DHA Test 27
1.9 Daphnia Test 28
1.10 Organisation of the Book 28
References 28
Chapter 2: Main Pollutants and Environmental Impacts of the Tanning Industry 32
2.1 Introduction 32
2.2 Soaking 34
2.3 Liming 35
2.4 De-liming, Bating and Pickling 36
2.5 Chrome Tanning 36
2.6 NaCl2 37
2.7 Organic Matter 37
2.8 Hydrogen Sulphide (H2S) 37
2.9 Chromium Salts 38
2.9.1 Chemistry of Chromium 38
2.9.2 Trivalent Chromium (Cr3+) 38
2.9.3 Hexavalent Chromium (Cr6+) 40
2.10 Chromium in the Environment 40
2.10.1 Water Systems 40
2.10.2 Soil Systems 41
2.10.3 Atmospheric Systems 42
2.10.4 Chromium Pathways in the Environment 43
2.11 Microorganisms and Plants 43
2.12 Chlorinated Phenols 44
2.12.1 Behaviour of Chlorophenols on Soils and Water 45
References 46
Chapter 3: Ecotoxicological Techniques and Assessment of Environmental Samples 51
3.1 Introduction 51
3.2 Toxicity Dissection 54
3.2.1 Sparging 54
3.2.2 Activated Charcoal Treatment 55
3.2.3 Filtration 55
3.2.4 pH Adjustment 55
3.3 Toxicity Testing Using Escherichia coli HB101 pUCD607 55
3.3.1 Resuscitation of Freeze Dried Cultures 62
3.3.2 Sample Addition and Luminometry Measurements 63
3.3.3 Data Analysis 63
3.4 Dehydrogenase Assay 63
3.4.1 Data Analysis 67
3.5 Daphnia Test 67
3.5.1 Invertebrate Trophic Level (Daphnia Magna) 70
3.6 Chemical Analysis 70
3.6.1 Sample Digestion (Sediments and Dust Samples) 70
3.6.2 Biological Oxygen Demand (BOD)/Dissolved Oxygen (DO) Determination 70
3.6.2.1 Effect of BOD/COD 71
3.6.3 Sulphate and Chloride Determination 72
3.6.4 Total Phenols 72
References 73
Chapter 4: Occupational Risk in the Tanning Industry 77
4.1 Introduction 77
4.2 Kinetic Phase 78
4.3 Dynamic Phase 79
4.4 Techniques Used in Determining Risks and Hazards 82
4.5 Characterisation of Tannery Dust and Image Analysis 82
4.6 Rapid and Efficient Technique to Characterise Hazards from Dusts 82
4.6.1 Dust Sampling Technique 82
4.6.2 Image Analysis 84
4.6.3 Data Analysis 84
4.6.4 Estimating the Concentration of Dust in the Tannery Air Environment 89
4.7 Screening of Tannery Dust Using a Luminescent Based Bacterial Biosensor 90
4.7.1 Solid Phase Ecotoxicity Testing 92
4.7.2 Liquid Phase (Aqueous) Ecotoxicity Testing 94
References 101
Chapter 5: Ecological Risk Assessment (ERA)of a Tanning Industry 105
5.1 Introduction 105
5.2 Categories of Hazardous Waste 107
5.3 Ecological Risk Assessment 107
5.4 Bioassays and Chemical Analysis in Context of ERA 109
5.4.1 Toxicity Test 109
5.4.2 Evaluation of Biomass Activity in Sediments 110
5.5 Weight of Evidence in Ecological Risk Assessment 111
5.6 Risk Questions 111
5.7 Objectives 112
5.8 Methodology 112
5.8.1 Assessment and Measurement End-Points 112
5.8.2 Bioassays 114
5.8.3 Sample Addition and Luminometry Measurements 114
5.8.4 Daphnia Test 114
5.8.5 Dehydrogenase Activity Test 114
5.8.6 Chemical Analysis 114
5.8.7 Data Analysis 114
5.9 Risk Assessment and Identification 115
5.9.1 Hazard Identification and Problem Formulation 115
5.9.2 Effluent Production 117
5.9.3 Effluent Composition and Resulting Stressor Characteristics 119
5.10 Exposure Assessment 122
5.10.1 End-Points and Conceptual Model 122
5.11 Ecological Effects/Toxicity Assessments 126
5.11.1 Contamination Levels for Identified Pollutants 126
5.12 Ecological Risk Characterisation 127
5.13 Ecological Risk Mitigation 128
5.13.1 Mitigation Strategies 129
5.13.2 Mitigation Calculation 129
5.13.3 Achieving the Targets Towards Mitigation Strategies 132
5.14 Conclusion 133
References 134
Chapter 6: General Discussion 138
6.1 Introduction 138
6.2 Suggestion for Future Work 143
References 145
Further Reading 147