Water purification has come a long way since the days of boiling pond-water over an ancient eagle scouts’ hastily made DIY camping fire. Modern water purification not just filters sediment, kills bacteria, removes microbes and scorches virus, but also balances pH levels. You know you are drinking good pure water when you can taste that crisp, balanced, pH 7 on your tongue.
The first step in modern water purification is the removal of large debris – no twigs, rocks or garbage floating in your Dasani!
The next step is called coagulation and flocculation. In this step chemicals are added to the water to assist in the removal of particles which were too small to be filtered out during the removal of large debris. Coagulants such as iron salts, aluminum sulfate, or iron chloride are added, some complex science stuff happens involving charges and ions, and then the water is free of many unwanted particles.
Next, water which has been successfully coagulate and flocculated is dumped into the sedimentation basin. Any remaining sediment will settle to the bottom of the tank. Water usually remains in the sedimentation tank for 1.5 to 4 hours. Unfortunately is formed on the bottom of the tank which must be mechanically extracted and cleaned.
Finally rapid sand filtration is used. Water flows vertically through layers of sand and activated carbon. Any remaining organic or inorganic particles are removed and water is ready for the final step of purification – disinfection.
Disinfection is accomplished through a final addition of chemicals to the now thoroughly filtered, coagulated, and flocculated water. This kills off any potential harmful pathogens or micro-organisms that may have escaped all the previous purification process. Once disinfection is completed the water is held in a tank for a period of time before it is bottled-up, labeled, shipped, and ready for your consumption.