Assessing the Potential for Photosynthetic Degradation of Per- and Polyfluoroalkyl Substances

PFAS is a prevalent groundwater contaminant. It has been known to cause many health issues for humans and animals including cancer and several diseases. A main problem faced with PFAS is contamination in groundwater. Remediation strategies have been and continue to be researched to try to mitigate this issue. Current treatment strategies to mitigate PFAS include the use of granular activated carbon, ion exchange, chemical oxidation, and many hybrid treatments. There has not been one treatment technology to date that has prevailed as the best due to monetary and time constraints. The main intention behind this research is to examine the effect of algae on PFAS degradation. The algal strain used was Chlorella Vulgaris. The experiments were all performed with either all light, all darkness, or a light-dark cycle of 5 hours of light and 1 hour of darkness to stimulate growth the most. The types of PFAS focused on throughout these studies were PFOA, PFDA, and PFNA. The addition of chemical constituents such as redox mediators and ferric iron were used to attempt to further this. A combination of growth experiments and resting cell suspensions was used in these experiments. The results of these experiments demonstrated little to no degradation, only losses instead. With and without the use of redox mediators there was still significant loss observed with PFNA in both growth and resting cell experiments. This being said it would be worthwhile to look further into PFNA degradation with algae and redox mediators. While many of the experiments were considered unsuccessful it was still helpful to look into this strategy.