ICMGP - Conference Presentation

Abstract Information :

As the human population increases, it is anticipated that demand for protein and water will surpass our current ability to provide these resources. Microalgae are one potential source of protein, and utilization of waste waters is a potential strategy to reduce fresh water resource consumption while meeting protein demands. However, many waste waters from municipal and agricultural sources contain trace or low levels of metal(oids) including mercury (Hg), cadmium (Cd), selenium (Se), and arsenic (As). The fate of these toxic elements in an industrial aquaculture setting remains to be evaluated for potential risks to consumers and industry workers. Biological transformation of Hg, Se, and As to volatile methylated forms may pose an exposure hazard to workers in a large-scale industrial setting, and bioaccumulation, sorption, or biotransformation into organic forms of these elements may also present a health concern to product consumers, including humans and livestock. This study explored the potential for Spirulina maxima, a common commercial algae product, to produce methylmercury, and volatilize Hg, Se, and As. The liquid and biomass phase partitioning of these elements was also quantified using a mass balance approach. Generally, Hg was predominantly recovered in the S. maxima biomass with some recovery in liquid and gaseous phases. Cd was similarly recovered in both biomass and liquid phases, while As and Se were predominantly recovered in the liquid phase. This partitioning behavior was observed when each element was tested individually, and when S. maxima was grown in the presence of all four elements simultaneously. Future work will take a similar approach to evaluate other potentially commercially important algae strains.