Vegreville, AB September 2, 2003 The Alberta Research Council says it has signed a one-year agreement with Alberta Environment to examine the effects of various water treatment processes on removing blue-green algae (cyanobacteria) and associated toxins from drinking water.
Blooms of blue-green algae are common in Alberta’s nutrient-rich ponds, streams and lakes. Many rural communities depend on small surface sources for drinking water, so utility operators must be aware of techniques for removing cyanobacteria and managing the risk of toxins entering their treatment plants. Toxins produced by some species of cyanobacteria can cause liver damage or promote liver cancer.
“Blue-green algae present several challenges to municipal water treatment facilities, including their tendency to clog filters and contribute to taste and odour quality concerns,” says Wendell James, research engineer with the Alberta Research Council. “However, the greater concern is the release by cyanobacteria of toxic substances, such as Microcystin-LR.”
“Water treatment processes like settling or flotation must be fine-tuned to remove cyanobacteria cells effectively," he adds. "Some current treatment practices can rupture the cells, releasing harmful toxins. Once released, these extra-cellular toxins are difficult to break down, requiring the use of strong chemical oxidants such as ozone.”
ARC scientists will experiment with two common species of cyanobacteria to establish better control strategies for removing cells and associated toxins. The study has two main components, which are:
– Optimizing settling and flotation processes for removing cyanobacteria cells, and
– Examining the potential benefits of chemical oxidation and ultraviolet irradiation for removing cells and destroying toxins.
James says he expects to complete the research project on blue-green algae by March 2004.