Abstract

Lack of water availability is a global crisis. Many arid countries are turning to desalination technologies in order to fulfill their water needs. Hypersaline water, brine, is the byproduct of desalination and can be dangerous to the environment if disposed of in an unsustainable manner. Research surrounding brine management focuses on improved methods of direct disposal, strategies of volume minimization, and reuse strategies. However, the mentioned brine management methods revolve around chemical and mechanical techniques requiring high technological skills, know-how and energy. This thesis aims to find biological solutions that use brine, with minimum resources, in low-cost, low-energy conditions to generate economic value and to minimize the negative effects of brine by attempting to reducing brine salinity. After conducting a thorough literature review, two possible organisms, with the potential of living in brine, algae and Artemia were selected. Different algae species are able to withstand high saline environments and uptake minerals from concentrated solutions; thus decreasing its overall salinity. Artemia sp. thrives in high saline conditions producing cysts of large economic value. This thesis aims to demonstrate that Artemia can live in brine and is a viable method for revenue generation and that the algae species Nannochloropsis sp. can also be adapted to live in brine and uptake nutrients, somewhat decreasing the salinity of brine. The Artemia and algae biomass can be sold, generating additional economic benefits and minimizing the cost of such a system, thus allowing for an economically, socially and environmentally safe way to utilize desalination waste. Marine microalga Nannochloropsis sp. was tested for its salt stress tolerance and salt accumulation capability in mediums of sea salt and brine with different concentrations and nutrients. In sea salt experiments, the alga grew best in salinity 80,000 mg.l-1 with F/2 nutrients where it reached an increase of 4-fold. In brine test BH with F/2 nutrients, excluding the vitamin stock solution and substituting NaNO3 with urea, the alga was able to reach a higher growth of 5-fold. Salt accumulation was minimal and thus will not decrease the TDS of brine. Nevertheless, the optimum conditions for growth of Nannochloropsis sp. in brine were identified, the biomass may be utilized for biofuel production, to generate economic value. Artemia experiments demonstrated the organism’s ability to survive in brine. The Artemia was able to survive for two months in a medium of 100% brine, indicating that a larger brine project may be conducted using this organism to generate economic value.

Department

Center for Applied Research on the Environment & Sustainability

Degree Name

MS in Sustainable Development

Graduation Date

Spring 2-11-2019

Submission Date

February 2019

First Advisor

Sewilam, Hani

Committee Member 1

Fouad, Walid

Committee Member 2

El-Bermawi, Nagy

Extent

134 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. The author has granted the American University in Cairo or its agents a non-exclusive license to archive this thesis, dissertation, paper, or record of study, and to make it accessible, in whole or in part, in all forms of media, now or hereafter known.

Institutional Review Board (IRB) Approval

Not necessary for this item

Comments

Al Alfi Foundation funded my studies, Research funds were awarded by AUC Graduate Research Grant.

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