Potable water is water that is safe to drink and use for cooking because it has been properly filtered and treated to remove contaminants and harmful bacteria.
Defining Potable Water
According to the provided reference, potable water is the water which is filtered and treated properly and is finally free from all contaminants and harmful bacteria. This purified water is fit to drink, or it can be called 'drinking water' after the purification processes and is safe for both cooking and drinking. In other words, it's water that meets specific health standards, making it safe for human consumption.
How Potable Water is Purified
The purification process typically involves multiple stages:
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Filtration: This removes suspended solids, sediments, and other particulate matter. Filtration can include:
- Sand filtration: Passing water through layers of sand to remove larger particles.
- Membrane filtration: Using fine membranes to filter out even smaller particles, bacteria, and some viruses.
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Disinfection: This kills or inactivates harmful bacteria, viruses, and other microorganisms. Common disinfection methods include:
- Chlorination: Adding chlorine to the water to kill pathogens. Chlorine is a cost-effective and widely used disinfectant.
- UV irradiation: Exposing water to ultraviolet (UV) light to damage the DNA of microorganisms and prevent them from reproducing.
- Ozonation: Using ozone gas to oxidize and kill pathogens. Ozone is a powerful disinfectant.
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Coagulation and Flocculation: Chemicals are added to the water to cause small particles to clump together (coagulation), forming larger, heavier particles called flocs (flocculation) that can be easily removed by sedimentation or filtration.
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Sedimentation: Allowing the water to sit quietly, enabling the heavier particles (flocs) to settle to the bottom for removal.
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pH Adjustment: Adjusting the pH of the water to optimize the effectiveness of disinfection and prevent corrosion of pipes.
The specific purification methods used can vary depending on the source water quality and the required standards for potable water. The goal is always to provide water that is free from harmful contaminants and safe for human consumption.
