Sodium hypochlorite, or more commonly known as “hypo” is typically injected at the final stage of water treatment to kill any remaining bacteria prior to the water being discharged back into the environment. It has also been used for pH control in the early stages of treatment.
Residual chlorine is toxic to aquatic species, so needs to be removed in a chlorination tank so that upon discharge, ideally it is not detectable. The effectiveness of overall disinfection depends on the quality of the water being treated, the type of disinfection being used, the disinfectant dosage (concentration and time), and other environmental variables.
Hypo is typically pumped into the chlorine contact channel at close to atmospheric pressures. The problem comes when the hypo becomes gaseous and causes other pump types to vapor lock and corrode.
Peristaltic pumps do not have this flaw - they can pump both liquid and gaseous fluids and are self priming, not to mention rugged and very simple to operate and maintain.