Valorization of Microalgal Biomass and Wastewater Treatment

Front Cover
Valorization of Microalgal Biomass and Wastewater Treatment
Copyright Page
Contents
List of contributors
About the editors
1 Scientometric analysis of microalgae wastewater treatment
1.1 Introduction
1.2 Methodology
1.3 Results and discussion
1.3.1 Analysis about the evolution of scientific production concerning microalgal use to treat wastewater
1.3.2 Analysis of the geographic distribution and contribution of studies about microalgal use to treat wastewater
1.3.3 Analysis of the 10 main sources of publications, journals, and research fields
1.3.4 Keyword analysis focusing on the use of microalgae for wastewater treatment
1.4 Conclusion
References
2 Scientometric analysis of consortium-based wastewater treatment
2.1 Introduction
2.2 Materials and methods
2.3 Results
2.3.1 Documents
2.3.2 Publishing authors
2.3.3 Publishing countries
2.3.4 Publishing institutions
2.3.5 Publishing year
2.3.6 Publishing journals
2.3.7 Citation analysis
2.4 Conclusion
Appendix A
References
3 Metabolic engineering of algal strains for enhancing wastewater treatment
3.1 Introduction
3.2 Genetic modification of algae to enhance wastewater treatment
3.2.1 Genetic engineering tools
3.2.2 Transformation technologies and selectable markers
3.2.3 Genome editing
3.3 Genetic engineering in algae for enhanced nutrient removal
3.4 Selection of marker genes
3.5 Reporter and promoter genes
3.6 Limitations in the field of genetically engineered algae
3.7 Future prospective
3.8 Conclusions
References
4 Lab-scale to commercial-scale cultivation of microalgae
4.1 Introduction
4.2 Cultivation of microalgae on a lab-scale
4.2.1 Nineteenth-century algal culturing
4.2.2 Twentieth-century algal culturing
4.2.2.1 Conventional algal culturing
4.2.2.2 Microalgal mass culturing
4.2.2.3 Mariculture of seaweeds
4.2.2.4 Cryopreservation
4.3 Commercial-scale production systems
4.3.1 Open cultivation system
4.3.2 Closed cultivation system
4.4 Commercial microalgae and processes
4.5 Challenges in scaling up
4.6 Commercial-scale outdoor culture
4.7 Strain selection
4.8 Contaminants and diseases
4.9 Online and daily monitoring
4.10 Regulations and standards
References
5 Valorization of microalgal biomass for biofuels
5.1 Introduction
5.2 Microalgae-based biofuels
5.2.1 Biodiesel
5.2.2 Biogas
5.2.2.1 Pretreatment
5.2.2.2 Nutrients balance
5.2.2.3 Temperature
5.2.2.4 Hydraulic retention time and organic loading rate
5.2.3 Biohydrogen
5.2.3.1 Biophotolysis
5.2.3.2 Dark fermentation
5.2.3.3 Photofermentation
5.2.4 Bioethanol
5.2.5 Biobutanol
5.2.6 Biocrude oil
5.3 Downstream processing for biofuels production
5.3.1 Harvesting
5.3.2 Drying
5.3.3 Cell disruption
5.3.4 Extraction
5.4 Life cycle analysis and techno-economic aspects of microalgal biofuels
5.4.1 Techno-economic analysis of biodiesel production from microalgae
5.4.2 Life cycle analysis of biodiesel production from microalgae
5.5 Challenges and prospects for cost-effective biofuels
5.6 Conclusions
References
Further reading
6 Valorization of microalgal biomass for food
6.1 Introduction
6.2 Products derived from microalgae
6.2.1 Proteins
6.2.1.1 Carotenoids
6.2.2 Pigments
6.2.2.1 Beta-carotene
6.2.2.2 Chlorophyll
6.2.3 Carbohydrates
6.2.3.1 Agar
6.2.3.2 Carrageenan
6.2.3.3 Alginate
6.2.3.4 Fucoidan
6.2.4 Lipids
6.3 Microalgae as human food
6.4 Parameters influencing the production of biomass
6.5 Processing
6.6 Cultivation
6.6.1 Batch
6.6.2 Fed-batch
6.6.3 Continuous
6.7 Cultivation systems
6.7.1 Open system
6.7.2 Closed systems
6.8 Need for pretreatment
6.9 Pretreatment
6.9.1 Drying
6.9.2 Mechanical cell disruption
6.9.2.1 High-pressure homogenizer
6.9.2.2 Sonication
6.9.2.3 Bead milling
6.9.2.4 Steam explosion
6.9.3 Nonmechanical/chemical cell disruption
6.9.3.1 Acid/alkali cell disruption
6.9.3.2 Enzyme
6.9.3.3 Size reduction
6.10 Harvesting/dewatering techniques
6.10.1 Flocculation
6.10.2 Gravity sedimentation
6.10.3 Filtration
6.10.4 Evaporation/drying
6.11 Extraction
6.11.1 Protein extraction
6.11.1.1 Organic solvent extraction
6.11.1.2 Sonication
6.11.2 Protein purification
6.11.3 Carbohydrate extraction
6.11.3.1 Alcoholic process
6.11.3.2 Potassium chloride process
6.11.3.3 Drum drying process
6.11.4 Lipid extraction
6.11.4.1 Solvent extraction
6.12 Conclusions
6.13 Future perspective
References
7 Valorization of microalgal biomass for fertilizers and nanoparticles
7.1 Introduction
7.2 Biofertilizer from microalgal biomass
7.2.1 Algal biofertilizer influence soil properties
7.2.2 Impact on enzyme activity and nutrient availability
7.2.3 Nutrient improvement through nitrogen fixation, carbon assimilation, phosphorus solubilization, and plant growth-prom...
7.3 Nanoparticles from microalgal biomass
7.3.1 Biosynthesis of nanoparticles using microalgae
7.3.1.1 Intracellular synthesis
7.3.1.2 Extracellular synthesis
7.3.2 Type of nanoparticle synthesized by microalgae
7.3.2.1 Silver (Ag) nanoparticles
7.3.2.2 Gold (Au) nanoparticles
7.3.3 Applications of nanoparticles from microalgal biomass
7.4 Challenges and perspective
References
8 Life cycle assessment of wastewater treatment by microalgae
8.1 Background
8.2 Wastewater: composition, environmental impacts, and phases of wastewater treatment
8.2.1 Composition
8.2.2 Environmental impacts
8.2.3 Phases of wastewater treatment
8.2.3.1 Primary/mechanical wastewater treatment phase
8.2.3.2 Secondary/biological wastewater treatment phase
8.2.3.3 Tertiary/chemical wastewater phase
8.2.3.4 Nanofiltration/membrane process wastewater phase
8.2.4 Nanofiltration
8.2.5 Ultrafiltration
8.2.6 Reverse osmosis
8.2.7 Biosorption
8.2.8 Hydrogels
8.3 Algal features and their potentiality in wastewater treatment
8.3.1 Macro versus microalgae
8.3.2 Potential of microalgae in wastewater treatment and production of high-value products
8.3.2.1 Photoautotrophic microalgae
8.3.2.2 Heterotrophic microalgae
8.3.2.3 Mixotrophic microalgae
8.3.3 Factors affecting the microalgae growth
8.3.3.1 Physical factors
8.3.3.2 Chemical factors
8.3.3.3 Biological factors
8.3.3.4 Operational factors
8.4 Life cycle assessment
8.4.1 Goal and scope
8.4.1.1 Life cycle inventory analysis
8.4.1.2 Life cycle impact assessment
8.4.1.3 Interpretation
8.5 Life cycle assessment of wastewater treatment by microalgae
8.5.1 Goal and scope
8.5.1.1 Cleaning of reactor
8.5.1.2 Preparation of culture medium
8.5.1.3 Cultivation
8.5.2 Open pond system
8.5.2.1 Closed system or photobioreactors
8.5.2.2 Flocculation
8.5.2.3 Biomass concentration
8.5.3 Gravity sedimentation
8.5.4 Flocculation
8.5.5 Flotation
8.5.6 Centrifugation
8.5.7 Filtration
8.5.8 Drying
8.5.8.1 Inventory analysis
8.5.8.2 Impacts assessment
8.5.8.3 Interpretation of the results
8.6 Conclusions
References
9 Life cycle assessment of microalgal biomass for valorization
9.1 Microalgae-based biorefinery and different routes
9.2 Life cycle assessment as a strategic tool for environmental feasibility analysis
9.3 Life cycle assessment in the context of microalgae biorefinery
9.3.1 Route 1—thermochemical processes: hydrothermal carbonization and hydrothermal liquefaction
9.3.2 Route 2—transesterification
9.3.3 Biological conversions of biomass: anaerobic digestion and fermentation
9.3.4 Route 4—biofertilizer
9.4 Uncertainty and sensitivity analysis
9.5 Challenges and opportunities in the light of life cycle assessment
References
10 Biorefinery and bioremediation potential of microalgae
10.1 Introduction
10.2 Microalgae-based biofuels and green energy production
10.3 Microalgal food and feed applications
10.3.1 Nutritional compounds of microalgae for feed and food applications
10.3.2 Health benefits arising from the production of microalgal products
10.3.3 Microalgae as feed ingredients result in increased animal product quality
10.3.4 Parameters affecting the commercial success of microalgae as food and feed ingredients
10.4 Biofertilizers
10.5 Pharmaceuticals, cosmetics, and microalgal bioplastics
10.6 Bioremediation potential of microalgae
10.7 Conclusions
References
11 Recent developments and challenges: a prospectus of microalgal biomass valorization
11.1 Historical perspective of microalgal biomass utilization
11.2 Wastewater as culture medium
11.3 Main valorization routes of wastewater-grown microalgal biomass: recent developments
11.3.1 Animal food
11.3.2 Energy routes
11.3.2.1 Biochemical processes
11.3.2.2 Hydrothermal process
11.3.3 Fertilizers
11.3.4 Other valorization routes
11.4 Challenges and opportunities for wastewater-grown microalgal biomass valorization
References
12 Nonconventional treatments of agro-industrial wastes and wastewaters by heterotrophic/mixotrophic cultivations of microa...
12.1 Introduction
12.2 Heterotrophic and mixotrophic culture of microalgae and Cyanobacteria versus autotrophy
12.3 Heterotrophic/mixotrophic cultivations of microalgae and Cyanobacteria in agro-industrial wastes and wastewaters
12.3.1 Pork wastes and wastewaters
12.3.2 Poultry wastes and wastewaters
12.3.3 Cattle wastes and wastewater
12.3.4 Dairy wastes and wastewaters
12.3.5 Olive oil mill wastes and wastewaters
12.3.6 Other agro-industrial wastes and wastewaters
12.4 Conclusions and future prospects
References
13 Ecological and environmental services of microalgae
13.1 Introduction
13.2 Microalgae—a multifaceted microorganism
13.2.1 The diverse approaches of cultivation
13.3 Ecological services of microalgae
13.3.1 Microalgae-derived human health supplements
13.3.2 Microalgae as a feed ingredient for livestock feed ingredient
13.3.3 Microalgal-based immunomodulatory properties
13.3.4 Microalgae-derived antioxidant properties
13.3.5 Microalgae-derived cosmetic products
13.4 Environmental services of microalgae
13.4.1 Microalgae: a tool for wastewater treatment
13.4.2 Microalgae for degradation of plastics
13.4.3 Microalgae for carbon dioxide sequestration
13.4.4 Microalgae for producing biofuels
13.5 Conclusions and future perspectives
References
14 Valorization of microalgae for biogas methane enhancement
14.1 Introduction
14.2 Microalgae-mediated biogas methane enrichment
14.3 Factors affecting biogas upgrading and lipid production
14.3.1 Biogas composition
14.3.2 Gas flow rate
14.3.3 Light Energy
14.3.3.1 Light intensity and photoperiods
14.3.3.2 Light wavelength
14.3.4 Concentration and source of nutrients
14.4 Biogas methane enrichment with wastewater treatment
14.5 Economics in biogas enrichment
14.6 Conclusions
References
15 Aquatic microalgal biofuel production
15.1 Introduction
15.2 Factors affecting the microalgae growth rate
15.2.1 Environmental factors
15.2.1.1 Potential of hydrogen (pH)
15.2.1.2 Nutrients
15.2.1.3 Temperature
15.2.1.4 Carbon dioxide
15.2.2 Processing parameters
15.2.2.1 Mixing
15.2.2.2 Light intensity
15.3 Feedstock harvesting
15.3.1 Sedimentation/centrifugation/flocculation
15.3.2 Fungi-assisted sedimentation
15.3.3 Flotation
15.4 Algae biofuels and conversion process
15.4.1 Thermochemical conversion
15.4.1.1 Pyrolysis
15.4.1.2 Liquefaction
15.4.1.3 Gasification
15.4.1.4 Direction combustion
15.4.1.5 Torrefaction
15.4.2 Biochemical conversion
15.4.3 Chemical reaction
15.5 Approaches to increase algal biofuel production
15.5.1 Selection of species or strain
15.5.2 Exploration of growth conditions and nutrients
15.5.3 Advancement in harvesting technology
15.5.4 Metabolic engineering
15.5.5 Biorefinery approach
15.6 Economic prospects of microalgal biofuels
15.6.1 The production cost of algal biomass feedstock
15.6.2 The production cost of crude algal oil
15.6.3 The production cost of biofuels from algal biomass feedstock
15.7 Engine performance and emission characteristics using algal biofuel
15.8 Global algal biofuel activities
15.9 Challenges and future perspective of biofuel production from algal biomass
15.9.1 Cultivation and harvesting
15.9.2 Microalgae compositional characteristics
15.9.3 Pretreatment for fractionation
15.9.4 Conversion technology and integrated biorefinery approach
References
16 Algal cultivation in the pursuit of emerging technology for sustainable development
16.1 Introduction
16.2 Internet of Things applied in microalgae biorefinery
16.2.1 Deployments of Internet of Things in microalgae cultivation
16.2.2 Internet of Things applied to the downstream processing
16.2.3 Robotized microalgae cells
16.3 Machine learning in microalgae cultivation and harvesting
16.4 Artificial intelligence in microalgae genetic engineering
16.5 Conclusions
References
Index
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