Đánh giá ảnh hưởng của vi tảo đến biến đổi khí hậu

Bioplastic products form microalgae Lipids 7%-23%, carbohydrates 5%-23%, and proteins 6%-52% are the main components of microalgae.. After comparing bioplastic production from 100% micro

ĐẠI HỌC QUỐC GIA THÀNH PHỐ HỒ CHÍ MINH

TRƯỜNG ĐẠI HỌC BÁCH KHOA KHOA MÔI TRƯỜNG VÀ TÀI NGUYÊN

BỘ MÔN KỸ THUẬT MÔI TRƯỜNG

BÀI TIỂU LUẬN

ĐÁNH GIÁ TÁC ĐỘNG CỦA VI TẢO

ĐẾN BIẾN ĐỔI KHÍ HẬU

HỌ VÀ TÊN: ĐINH CHÍ ĐẠT

MSSV: 1811848 GVHD: PGS.TS VÕ LÊ PHÚ

TP HỒ CHÍ MINH, THÁNG 04, NĂM 2023

Table of contents

I Introduction 3

1.1 Background 3

1.2 Characteristics of microalgae 3

1.3 Bioplastic 4

1.4 Biofuel 4

II Application of microalgae 5

2.1 Bioplastic products form microalgae 5

2.2 Microalgae as a source of biofuel 5

2.3 Microalgae in wastewater treatment 6

2.4 Bioproducts from microalgae 7

III Conclusion 8

I Introduction

1.1 Background

The last two decades' attempts to slow global warming have had positive outcomes, with greenhouse gas emissions rising at a slower rate during 2010 - 2019 than they performed during 2000 – 2009 [1] Each individual should participate in become environmental citizens which require basic scientific knowledge and insights into social, political, and economics systems that impact on our environment Science is a powerful tool for finding answers to environmental issues Known for its extensive application possibilities in the renewable energy, biopharmaceutical, and nutraceutical industries, microalgae have recently gained significant interest on a global scale Biofuels, bioactive pharmaceuticals, and food products can all be produced from microalgae in an environmentally friendly, economically feasible approach A number of microalgae species have been looked into for their potential to become high-value products with remarkable pharmacological and biological properties They are an ideal biofuel alternative to liquid fossil fuels in terms of price, renewability, and sustainability issues [2]

Since that microalgae have numerous applications, ranging from food to medical, they can also be seen as a solution for future sustainable development [3] The primary goal of this essay is to describe how microalgae can be used to reduce greenhouse gas emissions

1.2 Characteristics of microalgae

Microscopic algae, often known as microphytes, are not observable with the naked eye These are phytoplankton that typically inhabit the water column and sediment in freshwater and marine environments These are single-celled species that can be found alone, in chains, or in groups Their diameters can range from a few micrometers (μm) to a few hundred micrometers (μm), depending on the species Microalgae don't have roots, stems, or leaves like higher plants do They have been specifically designed for a setting where viscous forces dominant [4]

The chemical composition of microalgae changes widely in response to an array of parameters, including the species and the growth conditions It is not a characteristic constant element By changing their chemical composition in response to environmental variability, some microalgae are able to adapt to changes in environmental conditions Their capacity to switch

out phospholipids with non-phosphorus membrane lipids in phosphorus-depleted conditions

is a particularly great example By simply changing environmental elements including temperature, illumination, pH, CO2 supply, salt, and nutrients, microalgae can accumulate the necessary products to a particular level [5]

1.3 Bioplastic

A polymer that is created into a commercial product from a natural source or renewable resource is known as a bioplastic [7] A biodegradable plastic consists of material that breaks down as a result of the action of living things like fungi and microorganisms, bioplastic material has the ability to biodegrade in nature, but a biodegradable plastic cannot be referred

to bioplastic because the components differ in some cases A bioplastic is comparable to a traditional plastic, such as polypropylene, since it can be applied to manufacture commercial products The extraction and modification of natural polymers from biomass; polymerization

of bio-based monomers; and extraction of polymers generated in microorganisms are three generic approaches for generating plastics from natural sources Bioplastics can be made from natural organic components such as polysaccharides, proteins, and lipids, as well as plentiful starch Some researchers have succeeded in developing starch-based biodegradable bioplastics [8][9] Because of its natural composition and inexpensive cost, starch is a natural polymer derived from plants that can be utilized to manufacture biodegradable polymers

1.4 Biofuel

Biofuel is a fuel derived directly or indirectly from biomass, such as fuelwood, charcoal, bioethanol, biodiesel, biogas (methane), or biohydrogen However, most people associate biofuel with liquid biofuels (bioethanol, biodiesel, and straight vegetable oil) The term

"biofuels" refers to liquid biofuels used in transportation defined in [10] Biofuels are

classified into three types First one is solid biofuels refer to solid organic, non-fossil

biological material (also known as biomass) that can be used as a fuel for heat generation or electricity generation Solid biofuels are a product aggregate in energy statistics that includes charcoal, fuelwood, wood residues and byproducts, black liquor, bagasse, animal waste, other vegetal materials and residuals, and the renewable fraction of industrial waste Second one is biogas, a gas primarily composed of methane and carbon dioxide that is produced by anaerobic digestion of biomass or thermal processes from biomass, including waste biomass

In energy statistics, biogas is a product aggregate consisting of landfill gas, sewage sludge gas, other anaerobic digestion biogases, and thermal process biogases The last is liquid biofuels include all liquid fuels of natural origin (e.g., biomass and/or the biodegradable fraction of waste) that can be blended with or replaced by liquid fuels of fossil origin Liquid

biofuels is a product aggregate in energy statistics that includes biogasoline, biodiesels,

biojet kerosene, and other liquid biofuels

II Application of microalgae

2.1 Bioplastic products form microalgae

Lipids (7%-23%), carbohydrates (5%-23%), and proteins (6%-52%) are the main components

of microalgae Microalgae also contains calcium (0.1%-3.0%), magnesium (0.3%-0.7%), phosphorous (0.7%-1.5%), potassium (0.7%-2.4%), sodium (0.8%-2.7%), sulfur (0.4%-1.4%), copper (18-102 mg.kg-1), iron (1395-11,101 mg.kg-1), manganese (45-454 mg.kg-1), selenium (0-0.5 mg.kg-1), and zinc (28-64 mg.kg-1) [11] Chlorella is a genus of green algae found in freshwater commonly used for bioplastic studies which contains approximately 58% (by weight) protein It has higher crack resistance and thermal stability than Spirulina due to its dense cell walls [12] This species is frequently found in biomass-polymer blends After comparing bioplastic production from 100% microalgae biomass and blends containing additives and polymers, [12] discovered that blending is required for commercial applications

In current market mass production of bioplastic synthesis for microalgae biomass still a challenge as the technical requirement of outcome products haven’t meet

2.2 Microalgae as a source of biofuel

Because of their high photosynthetic efficiency to produce biomass and their higher growth rates and productivity when compared to conventional crops, microalgae have emerged as one

of the most promising alternative sources of lipid for use in biodiesel production They are easier to cultivate than many other types of plants and can produce a higher yield of oil for biodiesel production in addition to their rapid reproduction Microalgae with high oil content have the potential to produce oil yields up to 25 times greater than traditional biodiesel crops like oil palm Microalgae require only 0.1 m2 year per kg biodiesel of land to produce 121,104

kg of biodiesel per year, with an oil production of at least 70% oil by weight of dry biomass [14]

When compared to other biomass materials such as trees and crops, the costs of harvesting and transporting microalgae are relatively low Furthermore, they have no direct impact on the human food supply chain and environment In comparison to other plant sources, microalgae cultivation does not require a large amount of land Microalgae can be grown in a variety of environments that would be unsuitable for other crops, such as fresh, brackish, or salt water,

or non-arable lands [15] that would be unsuitable for conventional agriculture Also mass culturing of microalgae reduce the greenhouse gas as microalgae can fix carbon dioxide in the atmosphere, allowing for a reduction in atmospheric carbon dioxide levels Furthermore, the production of microalgae biomass can influence the biofixation of waste carbon dioxide, lowering emissions of a major greenhouse gas (1 kg dry algal biomass requires approximately 1.8 kg CO2)

2.3 Microalgae in wastewater treatment

Organic and inorganic pollutants are caused by organic and inorganic substances released into the environment as a result of domestic, agricultural, and industrial water activities The classic primary and secondary treatment processes for these wastewaters have been implemented in an increasing number of locations in order to eliminate easily settled materials and oxidize the organic material present in wastewater The end result is a clear, seemingly clean effluent that is discharged into natural bodies of water However this secondary effluent

is loaded with inorganic nitrogen and phosphorus, causing eutrophication and other long-term problems Microalgae culture is an intriguing step for wastewater treatment because it provides tertiary biotreatment while also producing potentially valuable biomass that can be used for a variety of purposes Because microalgae can use inorganic nitrogen and phosphorus for growth, they provide an elegant solution to tertiary and quandary treatments

One of the most promising technologies for advanced wastewater treatment and nutrient recovery in recent years has been the microalgae wastewater treatment process Many researchers have demonstrated the feasibility of using microalgae in wastewater treatment as

a supplement for tertiary wastewater treatment due to its high efficiencies on nutrient removal

in the advanced treatment of municipal, agricultural, and industrial wastewaters [16][17] It has been demonstrated that microalgae can efficiently utilize nutrients and grow well in wastewaters because their growth requires a high amount of nitrogen and phosphorous as well

as solar energy and CO 2 or organic matters as carbon sources for protein, nucleic acid, and phospholipid synthesis [18].From the standpoint of design and configuration, it can be divided into three categories: traditional open systems, enclosed photo-bioreactors (PBRs), and newly designed multi-technology hybrid systems

Fig 2.1 Types of photobioreactors (PBR) systems located at the AlgaePARC at Wageningen

University and Research [21]

These system often aiming for light distribution efficiency as not only use for wastewater treatment but also for biomass cultivation for other purpose such as bioplastic and biodiesel mentioned before that

2.4 Bioproducts from microalgae

Biomass of cultivated microalgae could also utilize for various product development such as food, healthcare and cosmetic products, biofertilizer Japan has a well-established market for edible algae products (algae soup) [19] and according to [20], China and Japan produce and consume the most dry algae globally There is use as whole cell (e.g., nori) and extracts, which can be used as an ingredient

Fig 2.2 A small bow of algae soup of Philippines

Food, agar, alginates, astaxanthin, beta-carotene, omega-3 fatty acids, phycocyanin,

phycoerythrin, and fucoxanthin are examples of potential high-value products (HVPs) from microalgae These are primarily used in pharmaceuticals, nutraceuticals, cosmeceuticals, and industrial sectors High-value products derived from microalgae improve the economics of a biorefinery approach while expanding market scope and opportunities [22]

III Conclusion

The application of microalgae in wastewater treatment optimize to mass produce biomass form microalgae as material for various purpose such as bioplastic, biofuels and many

bioproducts The meaning of reuse microalgae biomass from wastewater nutrients is to form

a cycle for material circulation, as we use discharge materials turn it into other product ingredients This prevent large amount of greenhouse gas emission from sludge incineration such as China in 2019 produce 48.8 × 108 kg CO2 from only sludge incineration and

drying The microalgae mass production and application also reduce GHG by fixation of

CO2 through process of photosynthesis up to 2.5 g.L-1 per day according to [25], many

photobioreactor system recently been designed and studied to enhance the CO2 fixation rate

of microalgae Therefor microalgae applications can have huge impact on the climate

changes in many ways

From self opinions I suggest that more of microalgae research should be focus only as

develop microalgae to become much more accessible for community in form of bioproducts and apply more microalgae wastewater treating system as not only reduce CO2 in

atmosphere but also prevent later on emission from sludge drying and incineration Study more about biofertilizer from microalgae as an alternative for tradition fertilize which cause salinity accumulation in soil

References

1 IPCC, 2022: Summary for Policymakers In: Climate Change 2022: Mitigation of Climate Change Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [P.R Shukla,J Skea, R Slade, A Al Khourdajie, R van Diemen, D McCollum, M Pathak,

S Some, P Vyas, R Fradera, M Belkacemi, A Hasija, G Lisboa, S Luz, J Malley, (eds.)] Cambridge University Press, Cambridge, UK and New York, NY, USA doi: 10.1017/9781009157926.001

2 Rahman, Khondokar (2020) Food and High Value Products from Microalgae: Market Opportunities and Challenges 10.1007/978-981-15-0169-2_1

3 Ji, S (2018) Study on Carbon Emission from Sludge Drying and Incineration Process.

4 Wikipedia contributors (2023) Microalgae Wikipedia.https://en.wikipedia.org/wiki/Microalgae

5 Tomásia Fernandes, Igor Fernandes, Carlos A.P Andrade, Nereida Cordeiro,Changes in fatty acid biosynthesis in marine microalgae as a response to medium nutrient availability, Algal Research, Volume 18, 2016, Pages 314-320, ISSN 2211-9264, https://doi.org/10.1016/j.algal.2016.07.005

6 Gupta, S K., & Bux, F (Eds.) (2019) Application of Microalgae in Wastewater Treatment

doi:10.1007/978-3-030-13909-4

7 Rudin, A., & Choi, P (2013) Biopolymers The Elements of Polymer Science & Engineering, 521–535

doi:10.1016/b978-0-12-382178-2.00013-4

8 Biocatalysis and Agricultural Biotechnology 27 (2020) 101540 8A Shafqat et al Kiing, S., Ee, S., Wong, S., Rajan, A., Yiu, P., 2011 Development of biodegradable plastic from sago and Bario rice starch blend

J Polymer Mater; New Delhi 28, 457–463

9 Abral, H., Dalimunthe, M H., Hartono, J., Efendi, R P., Asrofi, M., Sugiarti, E., … Kim, H.-J (2018)

Characterization of Tapioca Starch Biopolymer Composites Reinforced with Micro Scale Water Hyacinth Fibers Starch - Stärke, 70(7-8), 1700287 doi:10.1002/star.201700287

10 Publication card | FAO | Food and Agriculture Organization of the United Nations (n.d.) https://www.fao.org/publications/card/en/c/b51d93c9-61cc-5aad-bd5e-1d00c9a61fa7/

11 Tibbetts, S.M.; Milley, J.E.; Lall, S.P Chemical composition and nutritional properties of freshwater and marine microalgal biomass cultured in photobioreactors J Appl Phycol 2015, 27, 1109–1119

12 Zeller, M.A.; Hunt, R.; Jones, A.; Sharma, S Bioplastics and their thermoplastic blends from Spirulina and Chlorella microalgae J Appl Polym Sci 2013, 130, 3263–3275, doi:10.1002/app.39559

13 Minowa T, Yokoyama A-Y, Kishimoto M, Okakurat T Oil production from algal cells of Dunaliella tertiolecta by direct thermochemical liquefaction Fuel 1995;74(12):1735–8

14 Mata TM, Martins AA, Caetano NS Microalgae for biodiesel production and other applications: a review Renew Sust Energy Rev 2010;14:217–32

15 Patil V, Tran K-Q, Giselrod HR Towards sustainable production of biofuels from microalgae J Mol Sci 2008;9:1188–95

16 Lee, C.S., Lee, S.A., Ko, S.R., Oh, H.M., Ahn, C.Y., 2015 Effects of photoperiod on nutrient removal, biomass production, and algal-bacterial population dynamics in lab-scale photobioreactors treating municipal wastewater Water Res 68, 680–691

17 Oswald, W.J 1988 Micro-algae and waste-water treatment

18 Barsanti, L., Gualtieri, P., 2014 Algae: Anatomy, Biochemistry, and Biotechnology CRC Press

19 Holdt, S L., & Kraan, S (2011) Bioactive compounds in seaweed: Functional food applications and legislation Journal of Applied Phycology, 23, 543–597

20 Wellinger, A (2009) IEA bioenergy: Algal biomass, does it save the world? Short reflections Task 37

21 Wollmann, F., Dietze, S., Ackermann, J., Bley, T., Walther, T., Steingroewer, J., & Krujatz, F (2019) Microalgae wastewater treatment: Biological and technological approaches Engineering in Life Sciences doi:10.1002/elsc.201900071

22 Rahman, Khondokar (2020) Food and High Value Products from Microalgae: Market Opportunities and Challenges 10.1007/978-981-15-0169-2_1

23 Staff, Z (2022, August 9) Understanding the carbon impacts of Waste to Energy incineration - Zero Waste Europe Zero Waste Europe https://zerowasteeurope.eu/2020/03/understanding-the-carbon-impacts-of-waste-to-energy/

24 Wei, L., Zhu, F., Li, Q., Xue, C., Xia, X., Yu, H., … Bai, S (2020) Development, current state and future

trends of sludge management in China: Based on exploratory data and CO2-equivaient emissions analysis Environment International, 144, 106093 doi:10.1016/j.envint.2020.106093

25 Park, J., Kumar, G., Bakonyi, P., Peter, J., Nemestóthy, N., Koter, S., … Kim, S.-H (2020) Comparative Evaluation of CO2 Fixation of Microalgae Strains at Various CO2 Aeration Conditions Waste and Biomass Valorization doi:10.1007/s12649-020-01226-8