MONITORING CYANOBACTERIA USING PHYCOCYANIN PROBES AND POTENTIAL RISK OF IN-PLANT ACCUMULATION

This thesis evaluates the effectiveness of phycocyanin fluorescence probes as monitoring tools for the presence of cyanobacteria and/or their associated toxins in source water, as well as determines the cyanobacterial accumulation inside low-risk water treatment plant. Previous work reported that the direct correlations between phycocyanin raw readings and cyanobacterial parameters (e.g., cell count, biovolume, and cyanotoxin concentration) are not always promising. In this work, a review of the phycocyanin fluorescence probes is presented, and a probability of exceedance plot is developed and presented to predict relevant cyanobacterial parameters. Critical probe RFU values in terms of corresponding cyanobacterial monitoring threshold with various confidence levels are determined at each study site. Cyanobacterial in-plant accumulation is determined and quantified in three water treatment plants in Ontario from 2016 to 2017. The results show evident cyanobacteria and cyanotoxin (i.e., microcystin and anatoxin-a) accumulations inside low-risk plants. The potential worst-case scenario is predicted and microcystin with a concentration above Ontario drinking water guideline (4.1 Âľg/L) might end up in the finished water. More work needs to be done to predict the risk of exposure when cyanotoxins enter the distribution system.M.A.S