Traditionally, the use of chlorine gas was the most common method of wastewater disinfection. Chlorine gas itself is relatively inexpensive but is a highly toxic chemical that must be transported and handled with extreme caution.
It is stored under pressure in large tanks and is released into the wastewater as a gas. Sodium hypochlorite is a diluted liquid form of chlorine that is also commonly used.
Today, UV disinfection is widely accepted for municipal wastewater disinfection around the world. UV is rapidly growing, given it’s a safe and cost-effective alternative over chemical disinfection.
Also, it produces no disinfection by-products or a chlorine residual, which is harmful to the environment. The UV disinfection process adds nothing to the water but UV light, and therefore, has no impact on the chemical composition of the water.
Download PDF: Comparison of UV vs. Sodium Hypochlorite Fact Sheet