Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Farid Khoury - Thesis.pdf (7.25 MB)

ETD Abstract Container

Abstract Header

THE EFFECT OF LIGHT AND DARK PERIODS ON THE GROWTH OF CHLORELLA SOROKINIANA: MODELING & EXPERIMENTATION

Khoury, Farid F
http://rave.ohiolink.edu/etdc/view?acc_num=csu1607436360129811

Abstract Details

2020, Master of Science in Chemical Engineering, Cleveland State University, Washkewicz College of Engineering.
Microalgae are abundant unicellular photosynthetic organisms with more than 200,000 species. They are more efficient in harvesting solar energy than land-based plants, with green microalgae having more than ten times higher biodiesel productivity than the next best land-based crop. Their ability to grow in harsh environments, non-agricultural lands, and make use of wastewater, and the diversity of the products that can be extracted from them, which include cosmetics, pharmaceuticals, food supplements, biofuels, and many others, gives them the potential to replace fossil fuels and revolutionize the biotech industry. In order to move onto large scale production, first, the growth rate of the cell culture must be increased, which requires screening of promising species, studying their growth kinetics, and selecting their most suitable environment. Second, microalgae use their internal energy reservoirs (lipid bodies) during dark periods; nighttime biomass loss must be prevented. In this study, we analyzed the effect of light intensity on the growth of Chlorella sorokiniana, a promising species for biofuel production. We constructed a growth model that accurately predicts cell culture's growth response to varying irradiance conditions and photoperiods. We incorporated the concept of Monod kinetics into our model and quantified the effect of light intensity on biomass accumulation under light-limiting conditions. We determined that the empirically measured maximum growth rate has a value of 0.20 h-1, which is limited by the maximum photosynthetic rate. Additionally, we determined the Monod saturation constant to be 238 micromol per second per squared meter. We found that biomass loss rate due to respiration and other metabolic activities peaked during the day (8.7x10-3 h-1) and was constant during nighttime (1.8x10-3 h-1). We determined that 5% of the biomass gained during the 16-hour day period was lost during the following 8-hour dark period, which leads to a 16% lower biomass yield when compared to a continuously illuminated culture after nine days of cultivation at a constant temperature of 30oC in a well-mixed five-liter photobioreactor. Finally, we illustrated that illuminating the dark period with low-consumption red LEDs will prevent biomass loss and enhance cell replication.
Joanne Belovich (Committee Chair)
Jorge Gatica (Committee Member)
Chandra Kothapalli (Committee Member)
111 p.
Chemical Engineering
Microalgae; Biofuel; Light limited algae growth; Chlorella sorokiniana;

Recommended Citations

Citations

  • Khoury, F. F. (2020). THE EFFECT OF LIGHT AND DARK PERIODS ON THE GROWTH OF CHLORELLA SOROKINIANA: MODELING & EXPERIMENTATION [Master's thesis, Cleveland State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=csu1607436360129811

    APA Style (7th edition)

  • Khoury, Farid. THE EFFECT OF LIGHT AND DARK PERIODS ON THE GROWTH OF CHLORELLA SOROKINIANA: MODELING & EXPERIMENTATION. 2020. Cleveland State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=csu1607436360129811.

    MLA Style (8th edition)

  • Khoury, Farid. "THE EFFECT OF LIGHT AND DARK PERIODS ON THE GROWTH OF CHLORELLA SOROKINIANA: MODELING & EXPERIMENTATION." Master's thesis, Cleveland State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1607436360129811

    Chicago Manual of Style (17th edition)

csu1607436360129811
2,116
© 2020, some rights reserved.Creative Commons License THE EFFECT OF LIGHT AND DARK PERIODS ON THE GROWTH OF CHLORELLA SOROKINIANA: MODELING & EXPERIMENTATION by Farid F Khoury is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Cleveland State University and OhioLINK.