How It Works
Theory of Chlorination and Operation
Sodium hypochlorite, “NaOCl” (also known as “hypo”, “bleach”, or “liquid chlorine”), is a powerful oxidant that is used world-wide for the chlorination of water for disinfection
How on-site sodium hypochlorite is produced?
Salt is composed of sodium and chloride. When in solution and electricity DC is passed through special electrodes, the chlorides will disassociate to form chlorine. The process is basically as follows:
- Electrolysis occurs in a cell when a DC current is passed through a saline water solution or brine.
- At the anode: Oxidation of chloride ions produce chlorine (Cl2).
- At the cathode: Reduction of water produce sodium hydroxide (NaOH) and hydrogen (H2).
Liberated chlorine reacts with the sodium hydroxide to generate sodium hypochlorite (NaOCl).
The overall reaction is as follows:
2NaCl (salt) + H2O (water) NaOCl (hypo) + NaCl (salt) + H2 (hydrogen)
Dosing of chlorine into the water
One liter of 0.6% (6000 ppm) sodium hypochlorite solution mixed into 6000 liters of water will produce a 1ppm concentration. Likewise, to produce a 2 ppm concentration, add 2 liters of 0.6% sodium hypochlorite solution to 6000 liters of water.