In a study published in the journal Water Research, researchers from The Korea Institute of Science and Technology (KIST) have shown that it is possible to use powdered activated carbon in order to control algal blooms from blue-green algae in drinking water treatment plants.
Conventional drinking water treatment plants that do not have advanced water treatment facilities that use ozone and granular activated carbon to treat algal blooms typically use powdered activated carbon. Such powdered carbon absorbs algal micropollutants and reduced the risk of a bloom. However, traditional powdered activated carbon is limited in its slow adsorption that requires extended contact time with the algal micropollutants. In some water treatment plants, this poses a major obstacle.
To address this concern, the research team led by Dr. Kyung-Guen Song from the Water Cycle Research Center developed a powdered activated carbon with an improved adsorption rate that can better control algal blooms. To do so, they reduced the particle size of powdered active carbon by pulverizing it and subsequently increasing the surface area capable of adsorption.
The team showed that the taste- and odor-causing substances and toxic substances produced by blue-green algae were adsorbed considerably faster (20-150% increase depending on the substance) using their powdered carbon compared to the conventional powdered activated carbon.
Dr. Song commented, "Not only can the new powdered activated carbon be manufactured using quite a simple method, but it also has a fast adsorption rate, so it seems it will be possible to control algal blooms without the need to install high-cost facilities in existing conventional drinking water treatment plants where it is difficult to ensure sufficient contact time. Once this water treatment technology is disseminated widely, it will greatly help alleviate people's anxiety about drinking tap water."
Algal blooms are a public health concern because they make drinking water unpotable. As algal blooms become more widespread and frequent due to higher water temperatures and decreases in precipitation driven by climate change, it becomes ever more urgent to develop technologies that combat algal blooms in drinking water plants.