Water treatment at home to make it drinkable, after a catastrophe, for example, is an easily accessible technique that is considered by the World Health Organization (WHO) to be effective in preventing various diseases that can be transmitted by contaminated water, such as hepatitis A, cholera or typhoid fever.
For this, products with easy access can be used, such as bleach, but also sunlight and even boiling water.
The following are the ways that are considered effective for improving the microbial quality of water, reducing the chances of catching any disease:
1. Filters and water purifiers
Water filters are generally the simplest products and can be used when the water is dirty, but there is no suspicion that it is contaminated with harmful bacteria. These devices work from a central candle that retains impurities, such as earth and other sediments. Filters are able to remove dirt from the water and one of its advantages is that they do not need to use electricity, in addition to having a more affordable price, when compared to water purifiers.
However, the water purifier has an advantage over the filter, since, in addition to the central filter element, it usually has a purification chamber with special technologies, such as pumps or ultra-violet lamps, which are able to eliminate bacteria.
Whatever the filter or purifier, it is very important to check the certification seal of Inmetro, which is the National Institute of Metrology, Standardization and Industrial Quality, to make sure that the filter or the purifier is effective in making the water good for consumption.
2. Chemical disinfection
Chemical disinfection is another very effective way to eliminate bacteria from the water and make it drinkable, reducing health risks. The main ways are:
- Sodium hypochlorite / bleach: hypochlorite is great for disinfecting water, making it safe to drink, and is easily found in unscented bleach, which contains between 2 and 2.5% sodium hypochlorite. Only 2 drops should be used to purify 1 liter of water, and let it act for 15 to 30 minutes before drinking; Hydrosteril: is a product that can be used as an alternative to sodium hypochlorite and that was developed to eliminate bacteria from water and food, and can be found in some supermarkets. To make the water good for drinking, 2 drops of the product should be placed in 1 liter of water, and wait for 15 minutes. Tablets: they are practical for water purification, as they are easy to carry in bags or backpacks, and just add 1 tablet in 1 liter of water and wait to act for 15 to 30 minutes. Some examples most commonly found are Clor-in or Aquatabs. Iodine: it is easily found in pharmacies, and it is another option to disinfect the water, being also necessary 2 drops for each liter of water, and let it act for 20 to 30 minutes. Its use is not indicated for pregnant women, people with thyroid diseases or who use lithium-based drugs, as it can be harmful in these cases.
The methods for disinfecting or eliminating bacteria, although they are useful for leaving drinking water, do not eliminate certain impurities, such as heavy metals or lead, and therefore should be used only when filters or purifiers are not available.
3. Boil
Boiling water is also a very safe method of making water potable in areas that do not have filters or purifiers, however, to ensure that microorganisms have been eliminated, it is recommended to wipe the water with a clean cloth and then boil the water for at least 5 minutes.
The boiled water can have an unpleasant taste and, to make this taste disappear, you can put a slice of lemon while it cools or aerate the water, which can be done by changing it several times.
4. Other methods
In addition to filtration, purification, disinfection and boiling, there are also other alternatives for removing impurities from water, such as:
- Sun exposure of water, in a PET bottle or plastic container, and leave for 6 hours in the sun. This method is most suitable when the water is not visibly dirty; Decantation consists of leaving the water standing in a container for many hours, which allows the heavier dirt to settle to the bottom. The longer you stop, the greater the cleaning. Homemade filter, which can be done using a PET bottle, acrylic wool, fine gravel, activated carbon, sand and coarse gravel. A layer of acrylic wool should be inserted with the other ingredients, in the order mentioned. Then, just kill the bacteria with any of the disinfection methods.
These methods are not as effective as those previously mentioned, but they can be useful in inhospitable places or where there are no other alternatives. In this way, it is possible to drink water without putting your health at risk. Find out what the consequences of drinking contaminated water can be.
