Water available in various forms on Earth is not suitable for direct use. It is necessary to purify water before we use it for multiple purposes. The following concept will introduce the learners to water purification methods.
After reading the concept, students will be able to:
Each concept is explained to class 3 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Water Purification Methods provided in PDF format.
Water that we get in our homes usually comes from rivers. However, this water is contaminated with impurities like sand, silt, clay, soluble impurities and harmful germs.
So, water needs to be cleaned before it reaches our homes. There are different processes to purify water.
Distilled water is considered the purest form of water. We use a water purifier filter in our homes to obtain clean water.
Removing of impurities from the water to make it clean and suitable for drinking is called the purification of water.
Some common impurities found in water are—
Purification of water can be done by different methods. Some of these methods are done at home, while others are used in water treatment plants where water gets purified before being distributed. The common methods of water purification are—
When water is heated and brought to a rolling boil for about 20 minutes, the heat kills almost all the harmful germs from the water, making it suitable for drinking.
Chemicals such as chlorine tablets, potassium permanganate or alum can be added to water to kill harmful germs.
Electric water filters, with their complex components, help us get clean and pure water.
In the process of sedimentation, impure water is allowed to stand undisturbed in a container. As a result, impurities like mud or sand settle at the bottom as sediments. Clean water is then transferred into a clean container by the process of decantation.
In this method, impurities that do not dissolve in water are removed by passing the impure water through a filter paper or a muslin cloth.
In this process, impure water is first heated till it gets converted into steam. The impurities are left behind in the container. The steam obtained is then passed through a condenser, where it gets cooled and then changes back into liquid water.
Sunlight is used to disinfect water. The steps involved are as follows—
Soluble: Able to mix with water.
Run-off: Draining away of water from land.
Rolling boil: When water vigorously boils and bubbles start appearing continuously which cannot be stopped by stirring the water.
Bottled Water Is a Safe Option.
We cannot consider bottled water to be a safe option. The reason is that the bottles are made of plastic that contains chemicals. These chemicals leech into the water gradually, making it not so suitable for drinking.