The temporary hardness of water due to calcium bicarbonate can be remo...
Introduction:
Temporary hardness of water refers to the presence of dissolved calcium bicarbonate in the water, which can cause scaling and other issues. Fortunately, there are several methods to remove temporary hardness and improve the quality of water. In this response, we will discuss these methods in detail.
Methods to remove temporary hardness of water:
1. Boiling: Boiling is a simple and effective method to remove temporary hardness. When water is boiled, the dissolved calcium bicarbonate decomposes into calcium carbonate, which is insoluble and precipitates out. The precipitated calcium carbonate can then be removed by filtration.
2. Lime soda process: The lime soda process is a commonly used method to remove temporary hardness. It involves the addition of lime (calcium hydroxide) and soda ash (sodium carbonate) to the water. The calcium hydroxide reacts with the bicarbonate ions, forming insoluble calcium carbonate, which can be removed by filtration. The remaining sodium carbonate helps to maintain the pH of the water.
3. Ion exchange: Ion exchange is another effective method to remove temporary hardness. In this process, water passes through a resin bed containing ion exchange resin beads. These beads are typically coated with sodium ions. As the water flows through the resin bed, the calcium and magnesium ions in the water are exchanged with sodium ions, removing the temporary hardness. The resin beads need to be regenerated periodically by rinsing them with a concentrated sodium chloride solution.
4. Reverse osmosis: Reverse osmosis is a water purification process that can effectively remove temporary hardness. It involves forcing water through a semi-permeable membrane, which blocks the passage of dissolved minerals, including calcium and magnesium ions. The filtered water is collected, while the concentrated hardness ions are discharged as waste.
5. Chemical precipitation: Chemical precipitation is a method that involves adding chemicals such as lime or soda ash to water to precipitate the calcium and magnesium ions as insoluble compounds. These compounds can then be removed by sedimentation or filtration.
Conclusion:
Temporary hardness of water, caused by calcium bicarbonate, can be effectively removed using various methods. Boiling, lime soda process, ion exchange, reverse osmosis, and chemical precipitation are some of the commonly used methods to eliminate temporary hardness. The choice of method depends on factors such as the scale of water treatment needed and the available resources. Removing temporary hardness not only improves the quality of water but also helps prevent scaling and other issues associated with hard water.
The temporary hardness of water due to calcium bicarbonate can be remo...
By boiling;
During boiling, the soluble Mg(HCO3)2 is converted into insoluble Mg(OH)2
and Ca(HCO3)2 is changed into insoluble CaCO3.It is because of high solubility product of Mg(OH)2 to that of MgCO3, that Mg(OH)2 is precipitated. This percipitates can be removed by filtration.Filtrate thus obtained will be soft water.
clark's method;
In this method calculated amount of lime is added to hard water . It percipitates out calcium carbonate and magnesium hydroxide which can be filtered off.