Over the next few blog posts, we will look at several different types of disinfection that are used in water treatment, the positive and negatives of them and how they compare to each other. The first method we will examine is chlorine gas.
Chlorine gas has been used for about 100 years and is the most used disinfectant for water treatment (per number of systems using Cl2 not for volume of water treated). It is a widely available, strong disinfectant that will destroy several of the entities we are trying to remove such as coliforms, e-coli, bacteria and other pathogens.
Chlorine does have its risks, as well. An operator must be aware of all the safety protocols when handling or working around chlorine gas. This link will take you to a handbook for water and wastewater operators dealing with chlorine.
Chlorine gas has an expansion rate of 460 to 1, which is two-and-a-half times heavier than air, so it is important to use a vent fan when working with Cl2. Most treatment plants use 150-pound chlorine gas cylinders for their water treatment. An operator must be trained in handling these cylinders since it is at least a two-man job when replacing cylinders.
Please remember that even though we have been using chlorine gas for years, it still needs to be handled with care. One misstep and you could be in a life-and-death situation. Next blog, we will look at sodium hypochlorite.
CG “ Tar Heel”