Calcium hypochlorite is a chemical compound with formula Ca(ClO)2. It is widely used for water treatment and as a bleaching agent or disinfectant. This chemical is considered relatively stable and has greater available chlorine than sodium hypochlorite (liquid bleach).
Calcium hypochlorite is a white granular solid (or tablets compressed from the granules) with an odor of chlorine. Toxic, irritating to the skin. Noncombustible, but will accelerate the burning of combustible materials. Prolonged exposure to fire or heat may result in the vigorous decomposition of the material and rupture of the container. Diluted samples may undergo reactions as described above if they contain less than 39% available chlorine but take longer to become involved and react less vigorously. Used for water purification, disinfectant for swimming pools, for bleaching paper and textiles.
Calcium hypochlorite is more stable than sodium hypochlorite, and contains a higher chlorine concentration (30-75%). Like sodium hypochlorite, calcium hypochlorite also increases water pH, so it is advised to acidify the water during the disinfection process.
All forms of calcium hypochlorite contain insoluble residues that form sediments in the solution. It is important to eliminate the sediment before injecting the calcium hypochlorite solution into a treated water tank to avoid clogging.
Applications of Calcium chloride
Calcium hypochlorite can be used as:
- Drying and strengthening agent
- Retention agent
- Filter agent
- Wastewater treatment
- Oil chemical assistants
A point-of-use disinfection system consists of very simple equipment. People who collect their drinking water daily from lakes, rivers or wells are able to disinfect their water before using it. A bottle of liquid or a packet of solid treatment chemicals is provided along with a water storage container. The chemicals, which may include calcium or sodium hypochlorite, are measured into the water container to disinfect. Point-of-use treatment is certainly not as convenient as centralized water treatment, but evidence shows this simple, low-cost method reduces the risk of diarrheal disease and death.
Even in the developed world, point-of-use systems can be a life-saver when natural disasters, such as earthquakes and hurricanes, disrupt water supplies. Clean, safe water is a public health MUST and calcium hypochlorite helps to provide it, especially where it is needed most.