To some degree, there are only few places where we can find pure water. In fact, pure water does not appear in nature. The most common natural source of water is probably is the snow. Then the next is rainwater. But to some degree, rainwater contains dissolved gasses as it contact with the atmosphere. Traces of dissolved carbon dioxide, chlorides, sulfate, nitrate, and ammonia are often found in rainwater. Waters that comes from streams and lakes high up the mountain contains inorganic salts while water from rivers and lakes in the lower regions are usually polluted. All of these impurities
will have bad effect to our body in the long run. Even waters that come from springs and wells that have been naturally filtered through the ground are also not pure as it contains concentration of inorganic salts. Of all of these water sources, the presence of bacteria and other microorganism is also a big threat to human health.With this, we knew that water needs to be purified to some degree before it becomes safe to drink. And there are many methods that we can employ to purify water.
The simplest one is by means of storage. When we store water in a reservoir, some basic natural actions takes place. That is,
dissolved solids will settle down at the bottom of the reservoir. This process is known as sedimentation. Many bacteria also die when water is kept in a storage reservoir.But by simply storing water, we do not completely remove its impurities. Chemicals were added to promote better sedimentation. Water can also be aerated to remove the taste and odors as well as the dissolved gases on it.
For many years, man had discovered that water can be filtered through the sand. It is an effective way of removing majority of the bacteria present on the water. And as time goes by, various sand-filtering and other filtering methods was set-up to filter water. Special equipments with various filtrating agents were also invented to force water filtration to increase productivity.
But for many years, the most common method of purifying water is through the process called “chlorination”. This is because; the process is very cheap, very quick and a very effective method of water purifying. The process is as simple as adding 2 kilos of chlorine to nearly 4 million liters of water. The chlorine will kill almost 99.9% of all bacteria present in the water.
