Hammody, Dina and Semple, Kirk (2022) Mitigating Environmental Pollution Using Eukaryotic Algae. PhD thesis, Lancaster University.
Abstract
Aquatic systems are the main carrier of domestic and industrial wastes, including heavy metals (HM). HM are undegradable wastes that accumulate in the environment with time. The accumulation of HM has adverse human and environment health concerns. Applying chemical and physical treatment to immobilize or reduce the impact of HM is inefficient and costly. Biological treatment using eukaryotic algae has become an important subtract option for the treatment of polluted aquatic systems due to their low cost, efficiency, eco-friendly, sustainability and feasibility. Therefore, this thesis aimed to improve the resistance of eukaryotic algae to heavy metals through adaptation techniques to elevated concentrations of HM. The study shows the ability of algae to adapt to higher levels of heavy metals after a series of increases in metals concentration in the growth media. Also, the cell structure studies using Fourier Transform Infrared (FTIR) spectroscopy shows that algae have used the mechanism of cell structure alteration to cope with higher levels of metals. It is also found that the use of adapted microalgal phenotype significantly reduced the level of heavy metals used in the study from the solution. Therefore, the possibility of reusing the contaminated solution after treatment, has been studied through testing the ability of Daphnia magna to thrive in the algae-treated media solution. Results showed that daphnia was successfully able to live normally in the treated solution, suggesting that the treatment with adapted microalgal phenotype removed the metals and their toxic impact from the solution.