Clean water is water that is purified. Water purification is the process of removing undesirable substances and contaminants from war with an aim to make it disinfected, clean, and safe for human consumption.
71% of the Earth’s surface is covered in water. 97% of this is salt water and 3% is fresh water. Clean drinking water, also known as potable water, is essential for human life. We also use water for cleaning our clothes, showers, baths, flushing toilets, cooking and more. Water can be a source of many diseases, such as cholera or dysentery, so in modern times, water that is brought to homes has been cleaned and disinfected, making it safe to drink.
Early human settlements could only start to develop in areas close to a clean water supply, such as a river. Humans then dug wells to get water, which allowed for settlements away from rivers. Early civilizations built systems, like the aqueduct and irrigation, to redirect water courses to towns and cities where water was needed. The first doctor to notice that the quality of water could affect a person’s health was Alcamaeon of Croton in 470 BC.
In some developing countries, water supplies can be contaminated by sewage or other sources of bacteria. Contaminated water can contain pathogens which cause diseases such as cholera. If people don’t have access to clean water and drink contaminated water, they can die from these diseases. Access to clean water allows a community to thrive and grow, and some areas still do not have clean water readily available.
Coagulation and Flocculation
Flocculation is a process by which smaller particles are joined together to form large particles. These larger particles, called floc, are easier to remove from the water.
Sedimentation is a process of allowing the floc to settle to the bottom to remove it from the water.
After the larger particles have been removed, the water passes through filters of various compositions to remove other dissolved particles.
After filtration, the water is disinfected, often with chlorine, to kill any remaining pathogens.
The exact process that water goes through depends on the source of water. Ground water normally requires less filtering than surface water. Where fresh water is scarce, sea water can also be used as a source. The salt is removed from the water using a process known as desalination. Desalination can be a costly process.