‘Chlorine dioxide is most effective to combat Legionella in cooling towers’

Dubai, UAE, 5 November 2018: Legionella might be a well-known threat in cooling towers but it is something to be concerned about, highlighted Ronak Monga, Business Development Manager, Grundfos Middle East. When water is at approximately 25 degrees C, the exposure and mixture of water with air makes it perfect for bacterial growth, he said. Elaborating on a few methods to tackle the spread of Legionella, Monga said, “One method to treat Legionella is to heat water beyond 70 degrees C, but this is not possible in cooling towers.” The other, more commonly used, method is chlorine, which is not good enough, as it only fights 99% of pathogens and has no effect on Legionella, hence, does no good in solving the problem, said Monga. While suggesting the best practice, Monga said, “The ideal method is to use chlorine dioxide, ClO₂, which is effective.” However, he said that the chemical must be produced on site and must not be stored or transported. The solution is created by causing a reaction between two chemicals, sodium hydrochloric acid and chlorine dioxide, he said. The reaction needs to take place in a controlled environment to produce chlorine dioxide, he added. Monga highlighted cost as a major challenge, as it is an expensive solution. However, he said, there is a need to raise awareness about adopting the right kind of solution. He added, “If using such a mechanism is made a mandate, and if the municipality sets a deadline to make this a norm, we might be able to save on the energy, which is, in other scenarios, used to heat water to kill the germs.”