Technological Advancements in Product Valorization of Tea Waste

1 Global tea production and business opportunity

1.1 Introduction

1.2 Global production of tea

1.3 Business and trading aspect of tea

1.3.1 Global export of tea

1.3.2 Variation in the price of tea

1.4 Tea production in India and its export strategy

1.5 Different forms of tea

1.5.1 Black tea

1.5.2 Green tea

1.5.3 Yellow tea

1.5.4 Red tea

1.5.5 White tea

1.5.6 Dark tea

1.6 Summary
References

2 Tea processing techniques and waste management thereof

2.1 Introduction

2.2 Conventional methods for tea processing

2.2.1 Plucking

2.2.2 Withering

2.2.3 Breaking up

2.2.4 Crushing, tearing and curling

2.2.5 Fermentation

2.2.6 Drying

2.2.7 Grading and storage

2.3 Conventional methods for the disposal management of tea waste

2.3.1 Selling

2.3.2 Exporting

2.3.3 Feed for poultry, pig and fish

2.3.4 Feedstock for fertilizer and nutrients

2.3.5 Separation of bioactive chemical compounds

2.4 Summary and future recommendations
References 

3 Advancement in the extraction of bioactive compounds from tea leaves

3.1 Introduction

3.2 Different techniques for extraction of active biomolecules

3.2.1 Solvent extraction methods

3.2.2 Ultrasound-assisted extraction techniques

3.2.3 Microwave based techniques

3.2.4 High-pressure assisted methods

3.2.5 Super critical fluid extraction

3.3 Bioactive polyphenols and their importance in human health benefits

3.3.1 Tea polyphenols or flavonoids and their antioxidant action mechanism in human

3.3.2 Tea flavonols and their pharmacokinetics in human

3.4 Tea polysaccharides and their bioactivity

3.5 Technological progress towards the extraction of bioactive compounds from tea leaves and their applications

3.6 Summary and future recommendations
References

4 Tea waste-based value-added products

4.1 Introduction

4.2 Greener routes for the synthesis of metal nanoparticles from tea waste

4.2.1 Synthesis of iron based nanoparticles from tea waste

4.2.2 Synthesis of iron-oxide based nanoparticles from tea waste

4.2.3 Synthesis of silver based nanoparticles from tea waste

4.2.4 Synthesis of silver-oxide based nanoparticles from tea waste

4.3 Synthesis of carbon based materials from tea waste

4.3.1 Preparation of activated carbon from tea waste

4.3.2 Preparation of biochar from tea waste

4.3.3 One-step synthesis of magnetic tea biochar from tea waste

4.4 Applications of tea waste based value added products

4.5 Summary and future recommendations
References

5 Generation of different forms of bioenergy using tea waste

5.1 Introduction

5.2 Biohydrogen production from tea waste

5.3 Production of biomethane from waste tea powder

5.4 Pyrolysis of tea waste for the formation of syngas

5.5 Biodiesel from tea waste

5.6 Bioethanol from tea waste

5.7 Bioethanol production from spent tea waste using Saccharomyces cerevisiae

5.8 Enhancement in the calorific value of producer gas using spent tea waste as additive for rice husk

5.9 Latest technologies used for the generation of bioenergy from tea waste

5.10 Summary and future recommendations
References 

6 Removal of heavy metals from aqueous medium using tea waste as an adsorbent material

6.1 Introduction

6.2 Methods used for the preparation of tea waste based adsorbents and their applications

6.2.1 Adsorptive removal of lead and cadmium ions using tea waste based nanocomposites

6.2.2 Cr(VI) removal from synthetic waste water using tea waste

6.2.3 Tea waste based adsorbent for the removal of cobalt, cadmium and zinc from waste water

6.2.4 Adsorptive removal of lead, cadmium and copper ions from aqueous solutions using tea waste

6.2.5 Efficient removal of arsenic using magnetic porous materials derived from tea waste

6.2.6 FeCl3 treated tea waste for the treatment of arsenic contaminated water

6.2.7 Grafting copolymerization of acrylic acid on tea waste for heavy metal removals from aqueous system

6.3 Summary and future recommendations
References

7 Environmental applications of tea waste

7.1 Introduction

7.2 Ultrasound-assisted removal of pyridine using tea waste

7.3 Adsorptive removal of COD from water using tea waste biochar

7.4 Tea waste in the treatment of toxic dye effluent

7.5 Chemically modified tea waste in the treatment of fluoride containing waste water

7.6 Adsorptive removal of p–nitrophenol from waste water using activated tea waste

7.7 Utilization of tea waste for the removal of humic acid using tea waste

7.8 Proper utilization of toxic effects of waste tea in paste control management

7.9 Removal and recovery of uranium from aqueous solution using tea waste

7.10 Technological advancements in the environmental applications of tea waste

7.11 Summary and future recommendations
References

8 Emerging applications of solid waste of tea industry

8.1 Introduction

8.2 Preparation of hydrophobic bioplastics from tea waste

8.3 Application of tea waste as corrosion inhibitor in acidic media on boiler quality steel

8.4 Influence of tea waste in the preparation of bricks as pore making additives

8.5 Utilization of waste tea leaves as precursor material in sodium ion batteries

8.6 Application of functional dyes of tea waste in coloration, flame retardant and bioactive functionalization of silk

8.7 Role of spent tea leaves in constructing metal based electrocatalyst for oxygen reduction reactions

8.8 Summary and future recommendations
References