Algae

Human exposure to arsenic from natural as well as anthropogenic sources can lead to a detrimental impact to the nervous system, cardiovascular system and can also cause cancer. Historical agricultural runoff has led to an accumulation of arsenic in groundwater and soils around Lake Okeechobee and many golf courses in Florida. This research involved studying the removal of aqueous arsenic via adsorption using activated carbon derived from algae. Carbon derived from Sargassum removed 41.47% of arsenic after a contact time of 2 hours. Adsorbents created from blue-green algae showed essentially no arsenic removal under the same conditions. Various chemical additives were tested to improve arsenic adsorption as well. Modification of the adsorbent surface with magnesium chloride demonstrated an arsenic removal efficiency of 98.6% when added to commercial activated carbon. However, when magnesium chloride was used to modify the surface of Sargassum-derived carbon adsorbents, the arsenic removal efficiency after 2 hours was 26.7%. It is recommended to investigate other surface modification agents that can potentially improve adsorption of arsenic.

Aged unispecific cultures and environmental samples have been analyzed using HPLC-PDA in order to reveal chlorophyll-a degradation processes. Unispecific aging studies showed that alteration of chlorophyll occurred during senescence, and revealed that chlorophyll-a breakdown differs amongst various groups (i.e. species specificity). Sediment trap and sediment studies reveal that a variety of precursor chlorophyll-a derivatives are present, and that senescence and geochemistry, per se, overlap strongly. Many of the reactions in the Treibs' scheme occur before and during deposition. Intracellular senescence and diagenetic pathways have been examined in this work. Comparison of aged unispecific cultures and environmental samples strongly suggests major in puts from the senescence pathway. The results further supports the concept "pyro" reaction (loss of the carbomethoxy group) fates chlorophyll diagenesis towards true DPEP compounds.