Biodegradability of Conventional Plastics

Opis

Biodegradability of Conventional Plastics: Opportunities, Challenges, and Misconceptions brings together innovative research on the biodegradability of conventional plastics, providing an extensive overview of approaches and strategies that may be implemented, while also highlighting other methods for alleviating the eventual environmental impact of plastics. The book begins by providing a lifecycle assessment of plastics, the environmental impact of plastic waste, and the factors that affect the biodegradability of plastics. The different categories and terminologies surrounding bio-based plastics and biodegradable plastics are then defined and explained in detail, as are the issues surrounding bioplastics.

Other sections discuss biodegradability, approaches for enhanced biodegradability of various major types of plastics, including polyolefins, polyethylene terephthalate (PET), polystyrene, poly(vinyl chloride), automotive plastics and composites, and agricultural plastic waste. The final part of the book focuses on further techniques and emerging areas, including the utilization of chemical additives, nanomaterials, the role of microbes in terms of microbial degradation and microbial attaching, revalorization of plastic waste through industrial biotechnology, and future opportunities and challenges.

Explains the fundamentals of plastic waste, lifecycle assessment and factors that influence the biodegradability of plastics
Provides novel techniques for improved biodegradability, exploring areas such as pre-treatment, chemical additives, nanomaterials and microbial degradation
Addresses current challenges and limitations in relation to bio-based and biodegradable plastics, microplastics and nanoplastics from bioplastics and plastic waste

Spis treści

Front Cover 2
Biodegradability of Conventional Plastics 3
Biodegradability of Conventional Plastics: Opportunities, Challenges, and Misconceptions 5
Copyright 6
Contents 7
List of contributors 17
1 - Life cycle assessment and environmental impact of plastic waste 21
- Introduction 21
- Life cycle assessment 22
  - Definition of life cycle assessment 22
- Fate of plastics in the environment 23
- Movement of plastic trash: from land to aquatic ecosystem 23
  - Effect of plastic dumping on aquatic ecosystem 24
- Environmental impact of various plastic products 26
- Major repercussions of plastic waste 26

Front Cover 2
Biodegradability of Conventional Plastics 3
Biodegradability of Conventional Plastics: Opportunities, Challenges, and Misconceptions 5
Copyright 6
Contents 7
List of contributors 17
1 - Life cycle assessment and environmental impact of plastic waste 21
- Introduction 21
- Life cycle assessment 22
  - Definition of life cycle assessment 22
- Fate of plastics in the environment 23
- Movement of plastic trash: from land to aquatic ecosystem 23
  - Effect of plastic dumping on aquatic ecosystem 24
- Environmental impact of various plastic products 26
- Major repercussions of plastic waste 26
- Management of plastic wastes 28
- Global production of plastics and generation of waste 28
- Recommendations to reduce and control plastic wastes 30
- Future directions and recommendations 31
- Conclusions 33
- References 33
2 - Composition, properties and other factors influencing plastics biodegradability 37
- Introduction 37
- Microbial degradation of plastic materials 39
  - Mechanisms of biodegradation 39
  - Microorganisms involved in biodegradation 40
  - The plastisphere and future possibilities 41
  - Plastic-degrading enzymes 41
- Influence of plastic properties on biodegradation 43
  - Polymeric composition 43
  - Molecular properties 46
    - Crystallinity 46
    - Molecular weight 47
    - Hydrophobicity and morphology 47
  - Additive chemicals 48
- Influence of environmental and external parameters on plastic biodegradation 49
  - Temperature 51
  - Salinity and pH 52
  - Sunlight and UV exposure 53
  - Dissolved oxygen 53
  - Pressure 53
  - Fragmentation and transport of polymers in the marine environment 54
  - Moisture and humidity 54
  - Adsorption of pollutants to plastic debris 55
  - Biodegradation potentials in marine environments 55
  - Marine micro- and macrofauna involved in plastic degradation 56
  - Ghost fishing 57
- Conclusions, knowledge gaps, and future research 57
- Challenges and misconceptions 57
- References 58
3 - Bioplastics, biodegradable plastics, and degradation in natural environments 67
- Introduction 67
- Types of plastics 68
  - Synthetic plastics 68
  - Bioplastics 68
- Bioplastics classification 69
  - Biobased nonbiodegradable plastics 69
  - Biobased biodegradable plastic 70
    - Bioplastics synthesized from bioderived monomers 70
    - Bioplastics from biomass product 71
      - Starch-based bioplastics 72
      - Cellulosic-based bioplastics 72
      - Bioplastics based on plant and animal proteins 72
    - Bioplastics from microorganisms 71
    - Challenges of starch-based bioplastics 73
      - Hydrophilicity 74
      - Mechanical properties 74
      - Processability of starch-based materials 74
    - Solutions for starch-based bioplastic challenges 74
      - Improvement in hydrophilic property 75
      - Improvement in mechanical property 76
      - Problem statement 77
      - Improved processability 77
      - Thermal stability 77
    - Methodology 79
      - Preparation of starch biobased plastic from banana peels 79
      - Preparation of filler 80
    - Degradation 80
      - Types of degradation 81
        
        Photo (radiation) degradation 81
        
        Chemical degradation 82
        
        Oxo-degradation 82
        
        Thermal degradation 82
        
        Biological degradation (biodegradation) 82
      - Conclusion 83
      - References 83
    - 4 - Bioplastics overview: are bioplastics the panacea for our environmental woes? 89
      - Introduction 89
      - What are bioplastics? 90
      - Could bioplastics tackle the issue of natural plastic accumulation? 92
      - What are the likely environmental dangers of using bioplastics? 95
      - What is the capacity for bioplastics to tackle pollution caused by conventional petroleum-based plastics? 97
        
        Disposable plastic items 97
        
        Agricultural application (biodegradable plastic mulch film) 97
        
        High-end market 98
      - What are the opportunities and difficulties of using bioplastics? 98
      - Conclusion 99
      - References 100
    - 5 - Generation and impact of microplastics and nanoplastics from bioplastic sources 103
      - Introduction 103
      - Bioplastics: sources and sinks 105
      - Bioplastics market 107
        
        Biobased polyethylene 107
        
        Biobased polyvinyl chloride 108
        
        Biobased polypropylene 108
        
        Biobased polyethylene terephthalate 108
        
        Polylactic acid 109
        
        Cellulose acetate 109
      - Microplastics: sizes, forms, and manufacturing 109
      - Nanoplastics 110
      - Distribution of microplastics 110
        
        Aquatic environment 110
        
        Terrestrial environment 111
      - Fate of microplastics and nanoplastics 111
      - Spectroscopic techniques 112
        
        Fourier-transform infrared spectroscopy 112
        
        Raman spectroscopy 112
        
        Thermal degradation 113
      - Quantification of microplastics and nanoplastics 112
        
        Visual sorting 112
      - Mitigation of microplastics and nanoplastics 113
      - Health impacts of microplastics and nanoplastics 114
      - Knowledge gaps and key directions 114
      - References 115
      - Conclusion 115
    - 6 - Biodegradability of synthetic plastics: effective degradation mechanisms 121
      - Introduction 121
      - Market growth of synthetic polymers and challenges in degradation 122
      - Synthetic polymers and biodegradation by microbial species 122
        
        Biodegradation of polyethylene 124
        
        Biodegradation of polystyrene 129
        
        Biodegradation of polyvinyl chloride 129
      - Factors affecting the rate of biodegradation 129
      - Role of enzymes in biodegradation 131
      - Tests for assay of biodegradation of synthetic polymers 134
      - Conclusion 135
      - References 137
      - Further reading 140
    - 7 - Biodegradability of polyolefins: Processes and procedures 141
      - Introduction 141
      - Oxo-biodegradation mechanism of polyolefins 142
        
        What is biodegradation? 142
        
        Biodegradation mechanism of polyolefins 144
        
        Enhanced polyolefin biodegradation 147
        
        Blending and mixing 147
        
        Blending polyolefins with natural biodegradable polymers 147
        
        Blending polyolefins with synthetic biodegradable polymers 149
        
        Additives and prooxidants 150
        
        Pretreating with external conditions 150
        
        Ultraviolet light 152
        
        High energy radiation 152
        
        Thermal treatment 154
        
        Chemical treatment 154
        
        Incorporation with polymer nanocomposites 157
        
        Introduction to microbes and microbial products 158
        
        Genetically modified microorganisms 159
        
        Programmed biodegradation and its consequences 159
        
        Future trends 160
        
        Conclusion 161
        
        References 162
      - 8 - Biodegradability and current status of polyethylene terephthalate 175
        
        Introduction 175
        
        Synthesis and properties of polyethylene terephthalate 176
        
        Polyethylene terephthalate: applications and environmental impact 178
        
        Mechanism of polyethylene terephthalate biodegradation 180
        
        Polyethylene terephthalate-degrading microorganisms 181
        
        Algae 182
        
        Bacteria 182
        
        Actinomycetes 182
        
        Fungi 183
        
        Ideonella sakaiensis—the polyethylene terephthalate specialist 183
        
        Polyethylene terephthalate-hydrolyzing enzymes 184
        
        Bioeconomy of polyethylene terephthalate biodegradation and bioproduction 185
        
        Recent advances in polyethylene terephthalate production and degradation 187
        
        Future prospects 188
        
        References 189
      - 9 - Biodegradability and bioremediation of polystyrene-based pollutants: An overview of biological degradation of polystyrene an 199
        
        Introduction 199
        
        What are the forms of polystyrene? 201
        
        Why are polystyrene-based pollutants so hard to biodegrade? 203
        
        Biodegradability of polystyrene-a review of known methods 204
        
        Microorganisms (fungi, bacteria, and archaea) in biodegradation 204
        
        Larvae in biodegradation 207
        
        Invertebrates in biodegradation 211
        
        Plastic depolymerizing enzymes 212
        
        Advantages and implications of PS biodegradation 213
        
        Future perspectives 214
        
        References 215
      - 10 - Biodegradability of Polyvinyl chloride 221
        
        Introduction 221
        
        Types and properties of PVC 222
        
        PVC waste and environmental challenges 223
        
        PVC disposal methods 224
        
        Physical treatment 225
        
        Chemical treatment 226
        
        Biological treatment 226
        
        Stages of PVC biodegradation 226
        
        Colonization 227
        
        Biodeterioration 227
        
        Biofragmentation 228
        
        Assimilation and mineralization 228
        
        Factors affecting PVC biodegradability 228
        
        PVC-degrading insects 230
        
        PVC-degrading microorganisms 230
        
        Bacteria 230
        
        Fungi 231
        
        PVC-degrading enzymes 231
        
        Conclusion and prospects 233
        
        References 234
      - 11 - Biodegradability of automotive plastics and composites 241
        
        Introduction 241
        
        Plastic biodegradation challenges 245
        
        Plastic pollution, an environmental health concern 245
        
        Remediation methods for plastics 246
        
        Plastics biodegradation 246
        
        Polypropylene 247
        
        Polyurethane 247
        
        Polyvinyl chloride 249
        
        Best practices for plastics biodegradation 250
        
        Factors affecting plastics biodegradation by microbes 251
        
        Biodegradation of plastics: steps and mechanism 251
        
        Biodeterioration 251
        
        Mineralization 251
        
        Biofragmentation 251
        
        Assimilation 251
        
        Polymer composites 252
        
        Biodegradation of polymer composites 254
        
        Future prospects 256
        
        Conclusion 257
        
        References 258
        
        12 - Biodegradability of agricultural plastic waste 263
        
        Introduction 263
        
        Issues and consequences of agricultural plastic waste 265
        
        Misunderstanding (Rujnić-Sokele & Pilipović, 2017) 265
        
        Indistinguishable nature (Razza & Innocenti, 2012) 267
        
        Uncontrolled burning of agricultural plastic waste (Briassoulis et al., 2013) 267
        
        High cost (Zheng et al., 2005) 268
        
        Infrastructure 268
        
        Analysis of agricultural plastic wastes 268
        
        Mapping of agricultural plastic wastes 269
        
        Management of plastic waste 270
        
        Source reduction 270
        
        Improved product durability 271
        
        Reduced packaging 271
        
        Product reuse 271
        
        Product safety associated with aesthetic pollution 271
        
        Accidents 272
        
        Physical and mental health issues 272
        
        Monetary losses 272
        
        Loss of the regional natural beauty 272
        
        Inferior quality of life 272
        
        Significance of managing plastic wastes 272
        
        Less waste sent to landfills or incinerators 273
        
        Legal requirements 273
        
        Customized commercial waste management services 273
        
        Environmental impact 273
        
        Advantages of biodegradable plastic 273
        
        Improved human health 273
        
        Conclusion 274
        
        Reduced energy to manufacture 274
        
        References 274
        
        Fewer harmful substances released during breakdown 274
        
        13 - Utilization of chemical additives to enhance biodegradability of plastics 279
        
        Introduction 279
        
        Biodegradable plastic 281
        
        Chemical additives 284
        
        Biodegradation-promoting additives 284
        
        Accelerating degradation 287
        
        Inorganic oxo-degradation agents 288
        
        Organic prodegradation agents 290
        
        Blending with natural polymers 291
        
        Starch 291
        
        Protein 292
        
        Chitosan 292
        
        Reinforcement with natural fibers 292
        
        Scheme for allocating degradation agents 292
        
        Commercially available degradation-promoting additives 293
        
        Conclusions 294
        
        References 295
        
        Acknowledgments 295
        
        14 - The role of nanomaterials in plastics biodegradability 303
        
        Introduction 303
        
        Environmental concerns for microplastics and nanoplastics 304
        
        Remediation techniques for plastic pollution 307
        
        Bioplastics: a new generation of polymers 308
        
        Types of bioplastics 309
        
        Polyhydroxyalkanoate 310
        
        Polylactic acid 310
        
        Limitations of bioplastics 310
        
        Biodegradation mechanism 311
        
        Biodegradation of plastics via microorganisms 312
        
        Biodegradation of plastics via nanomaterials 314
        
        Biodegradation of various polymers 318
        
        Degradation of polypropylene 319
        
        Photo- and thermal degradation of polypropylene 319
        
        Biodegradation of polypropylene 320
        
        Polyesters 320
        
        Photothermal degradation of polyethylene terephthalate 321
        
        Conclusion and future scope 321
        
        References 322
        
        Acknowledgments 322
        
        15 - Microbial attachment studies on “plastic-specific” microorganisms 329
        
        Introduction 329
        
        Background of plastics within the environment 331
  - Fossil-based biodegradable plastic 70

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