Lime softens water through a chemical process that removes hardness-causing minerals. The treatment involves adding lime, or a combination of lime and soda ash, to the water.
Here's a breakdown of the process:
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The Chemical Reaction: The lime (calcium hydroxide) reacts with the hardness in the water, which is primarily caused by calcium and magnesium ions, and the natural alkalinity present. According to the reference, the lime and soda ash react with the hardness and natural alkalinity in the water to form insoluble compounds.
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Formation of Insoluble Compounds: This reaction leads to the formation of insoluble compounds. These compounds are substances that do not dissolve in water and therefore, become solid particles.
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Precipitation: The insoluble compounds then precipitate out of the water. Precipitation is the process where a dissolved substance comes out of the solution in the form of a solid.
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Sedimentation and Filtration: Finally, these precipitated solids are removed through sedimentation, where they settle to the bottom of a tank, and filtration, where the remaining particles are trapped by filters.
In essence, lime softening converts dissolved hardness minerals into solid particles that can be easily removed, resulting in softer water.
