Water treatment is treating water to make it suitable to be used. Providing drinking water is one of the main uses of water treatment.
Many factories also need very clean water to make steam or to make high quality products. Some of this water has to be made very pure with almost no other chemicals dissolved in it.
Treating sewage so that it does not cause harm to the environment is another kind of water treatment.
Saline water can be treated by desalination to yield fresh water. Two main processes are used, reverse osmosis or distillation. Both methods require more energy than water treatment of local surface waters, and are rarely used where good fresh water is available.
Methods[change | change source]
- Filtration - The clear water on top passes through filters composed of sand, gravel and charcoal to remove dissolved particles such as dust, parasites, bacteria, viruses and chemicals.
- Disinfection - Chlorine or chloramine is added to kill parasites, bacteria, viruses and germs.
- Coagulation / Flocculation. Coagulation is adding liquid aluminum sulfate or alum and/or polymer to raw or untreated water.
- Sedimentation. When water and flocs undergo the treatment process, they go into sedimentation basins.
- Sludge Drying.
- pH Correction.