Purificação da água

Shanna Freeman

The water that is consumed can be called drinking water , unlike the treated water which can be used for bathing or cleaning. In the United States, the Environmental Protection Agency establishes maximum levels for the 90 most common pollutants. If something happens to the water supply, the supplier has to contact people to warn them about the precautions that should be taken.

polluted canal
Photodisc / Houses next to a polluted canal in Manila, Philippines

The water treatment requires six basic steps:

  • in coagulation , coagulants such as lime and aluminum sulfate are added to the water, which causes the particles to stick together impurities;
  • then water is busy and form larger substances called flakes ;
  • The process of sedimentation requires that the water remains still for 24 hours, allowing the flakes to sediment at the bottom;
  • then, the water is filtered , disinfected (generally chlorine) and aerated ;
  • the aeration helps remove certain pollutants, such as radon.

Survival Techniques with water

If the water is contaminated and you do not have bottled water available, can purify it a few different ways. If it is cloudy, filter it first with a clean cloth or wait for the resídos settle and then remove the water clean. Then you can boil water for one minute to kill most disease-causing organisms.

You can also add an eighth of a teaspoon of household bleach per 3 liters of water (or follow the instructions on the label) tea. You should double the amount if the water is discolored or cloudy. Stir and let sit for 30 minutes. Bleach tablets are sold in stores for camping accessories to purify water and let it drinkable. You can also use five drops of iodine per gallon to disinfect water.

Keep boiled or disinfected water in clean, covered containers. If boiled water is tasteless or taste of chlorine is too strong, add the water from one container to another.

In the next section, we take a closer look on how exactly the water circulates in the cells of an animal and a plant.