Chlorination is disinfection of water with the application of chlorine. Other methods for disinfecting water are UV systems, ozone generator, silver ionization, etc. However these methods are not as popular as chlorination because those are expensive and have residual effects. For disinfecting water, chlorine is used in either form of chlorine gas, bleaching powder and hypochlorite solutions.
Electro chlorination is one method of chlorination using electrolysis process. In this method saline seawater or brine solution is converted into hypochlorite solutions. When direct current is passed through the solution containing electrodes, electrolysis of Sodium Chloride takes place. The reaction can be put forth as:
NaCl + H2O + Energy = NaOCl + H2
The hypochlorite solution is stored and hydrogen is removed by air blowing using blower fans. Initially electro chlorination process is in batches and with the consideration of energy savings microprocessor based systems are used to generate chlorine on a continuous basis. Although the system is pre programmed, it needs an intermittent intervention of the operator. The most important aspect of this system is that even if the power is available for a few hours the generated chlorine is enough for long operation use.
Benefits of Electro Chlorination: Compared to conventional method of chlorination, Electro chlorination has following major advantages:
- It eliminates the hazard of chlorine gas leakage.
- No dependency on external sources of chlorine supply because chlorine can be produced onsite using common salt as a raw materials.
- Pipe choking incidence (vacuum system) is minimized to almost zero level.
- Eliminate the equipment of space due to stocking of chlorine gas cylinder.
- The duty life of electro chlorination plant has the higher investment return (ROR) compared to the conventional chlorination plant.
- Maintenance and installation is easy and cost effective.
Maintenance for electrolysis process: Calcium carbonate and the magnesium hydroxide used to deposit on the cathode part which cause scaling. This scaling can be removed using diluted HCL. Other than this proper maintenance of electrodes is necessary to increase the life of the electrodes.
Due to the above mentioned benefits of electro chlorination; is gaining popularity for disinfecting water. Although it is as effective as chlorine gas however it does impose any hazards associated with the use of the chlorine gas.