One of the most direct impacts of algal blooms on humans is the safety of drinking water. The August 2014 harmful algal bloom in Toledo shut off water for more than three days, an impact felt by residents and businesses alike. In addition to monitoring bloom locations and adjusting both water intake and treatment methods accordingly, new treatments for contaminated drinking water are being developed to remove both algal particles in general and the toxins produced by cyanobacteria in particular.
Dr. Youngwoo Seo at the University of Toledo, along with Dr. Isabel Escobar at the University of Kentucky, are developing new methods to remove microcystin, the main toxin produced by harmful algal blooms, from drinking water using various filtration methods as well as ozone gas.
“We currently study multiple processes in the water treatment train, and each step can provide an additional barrier to remove a contaminant from water,” Seo explained. “As part of the study, we consider both conventional and membrane filtration systems, coupled with ozonation that can oxidize and break down all the organic matter, including algal toxin, in the water.”
Laboratory results so far have shown that bubbling ozone into a microcystin solution can lead to 100% destruction of the toxin, but further experiments will be needed to achieve similar results at the desired ozone concentration and treatment time with filtration. A range of filtration systems are also showing promising results, removing up to 96.9% of microcystin from the tested solutions.
Once these separate experiments are completed, combinations of ozone and filtration systems will be examined to determine the best pairing for toxin removal and cost effectiveness. The laboratory models can eventually be scaled up for use at water treatment plants that deal with harmful algal blooms in their water supply.