Public water system has huge responsibilities of turning surface water into potable water. The water treatment process not only gets rid of sediments and harmful toxic, but also various microbes, germs and bacteria that can spread disease. Surface water source especially has great risk of contaminations; therefore, public water system needs to have sets of sophisticated steps in turning this water source into potable water for public consumption.
Steps in Water Treatment Process
Water treatment process in public water system uses several steps, which are:
- Coagulation. This is the first step to get rid of dirt and sediments. Chemicals are added into the water to coagulate dirt and sediments. The chemicals bind with the particles in the dirt and sediments, turning them into larger particles (floc). This process is called flocculation.
- Sedimentation. In this water treatment process, the coagulated particles are slowly weighed down to the bottom of special water container/tank. This leaves cleaner water on top.
- Filtration. In this process, the water on top (separated from the coagulated particles on the bottom) is filtered to remove smaller, dissolved particles, such as parasites, smaller dust, bacteria, chemicals and viruses. This water treatment process involves several layers of filter composition: sand, gravel, charcoal.
- Disinfection. This is a very important water treatment process, since unseen bacteria, germs and viruses must be terminated before the water is distributed to houses and public buildings. Chloramine and chlorine are among the most widely used disinfectant.
- Fluoridation. This process is done as public health service to improve dental health.
These steps of water treatment process are standard among various public water systems in the world, but some countries often have better treatment quality than others, resulting in huge differences in tap water qualities. We can drink tap water directly from faucet in some countries, but in other countries, that can make us sick. Also, water treatment process for surface water is usually more complicated because surface water is more prone to contamination.
Water Treatment Process at Home
Countries like the US usually have drinkable tap water thanks to the public water treatment process, but sometimes, household owners have their own water treatment system at home to ensure the quality of drinking water. Household water treatment process often consists of several steps, such as:
- Filtration, which is usually done by several layers of filter (simpler version of filtration process in public water system).
- Water softener, which is used to ‘reduce the hardness’ of hard water by replacing its magnesium and calcium ions with potassium or sodium.
- Distillation, which is a process of getting the purest form of water with steam condensation.
- Disinfection, which can be done with chemicals like chlorine dioxide and ozone or heat and UV light.
In short, water treatment process in public water system must consist of several important steps until the water becomes potable, especially if the source if surface water. However, home water treatment, which has similar steps yet simpler, is advisable for household owners who want to improve safety factor in their drinking water.