Water Treatment Process

More and more people today are concerned about the quality of our water supplies. Whether they are using water for industrial purposes, commercial or personal consumption, there is a great need to look into the quality and health level of the water we are all using.

Contrary to what some people believe, there is no such thing as 100% pure water. All water contains contaminants although not all may be harmful to our health. However, over the past decades, the contaminants found in our water supplies have come to include toxic compounds and substances that can kill plants and animals down the food chain, even humans.

Some of these contaminants include but are not limited to the following:

* Parasites
* Giardia
* Cryptosporidium
* Campylobacter
* Bacteria
* Algae
* Viruses
* Fungi
* Minerals (including toxic metals like lead and copper)

Water treatment process refers to the reduction, or complete removal, of these contaminants from raw water, resulting in water that is safer and cleaner for use as drinking water.

But water treatment processes are confined for that purpose alone. The process may also be used to produce water that is pure enough for other desired end-use, other than human consumption. Water treatment processes are also useful for industrial applications so that waste water may be freely disposed of for reuse in the environment.

The Stages of a Typical Water Treatment Process

There are three principal stages involved in a typical water treatment process.

Primary Stage

This stage of water treatment aims to remove the large solids from water. It involves 5 sub-processes:

* Pumping and containment
* Screening
* Storage
* Pre-conditioning
* Pre-chlorination

Secondary Stage

The second stage of the water treatment process includes a wide range of techniques, either of which may be used to remove the finer solids, microorganisms, and other dissolved organic and inorganic compounds. As to what technique to use will depend on the type of water being treated. Below are some of the techniques that may be used at this stage of the water treatment process:

* pH adjustment
* Coagulation and flocculation
* Sedimentation
* Filtration
* Slow sand filters
* Ultrafiltration membranes

Tertiary Stage

Otherwise referred to as the “disinfection” stage, this is the final step in a water treatment process. Disinfectants are introduced at this final stage in order to destroy any pathogens that were able to pass through the filters in the second stage.

The types of disinfectants used may include the following:

* Chlorine
* Chlorine dioxide
* Chloramines
* Ozone (O3)
* UV radiation

There may be other disinfectants used. As said earlier, the disinfection technique depends on the type of water being treated.