You can survive without food for several weeks as your body will gradually switch to using stored fats and proteins for energy. But cut off the water supply and he will die in a few days. Water equals life: it’s that simple. About two thirds of your body (up to 75% if you are a child) is H2O.
Your bones, which you may think of as completely solid, are also about 25% water. On average, we need 2.4 liters (0.6 gallons) of water a day to stay healthy (although we don’t have to drink any of that, we get a lot of water from food). With water so important to our lives, it’s no wonder we like it clean, pure, and tasty. This is one of the reasons why people spend so much money on water filters that can remove harmful impurities. How do they work and do we really need them? Let’s take a closer look!
How water filters work
Thanks in large part to an unusual molecular structure, water is remarkably good at dissolving things. (We go over this in more detail in our main article on water.) Sometimes useful: if you want to remove the dust from your jeans, just throw them in the washing machine with a little detergent and the water and soap will remove the mud. away like a magnet. But clearly there is also a downside to this. All of our water constantly circulates in the environment in what is known as the water cycle. One minute you flow through a river or float on a cloud, the next one flows from your tap (tap), sitting in a glass at your table, or flushing the toilet. How do you know that the water you are about to drink, with its brilliant ability to attract and dissolve dirt, has not acquired all sorts of evil during its journey through the Earth and the atmosphere? If you want to be sure, you can run it through a water filter.
Physical and chemical filtration
Water filters use two different techniques to remove dirt. Physical filtration means filtering the water to remove the largest impurities. In other words, a physical filter is a glorified sieve, perhaps a piece of thin gauze or a very thin textile membrane. (If you have an electric kettle, it probably has a filter like this built into the spout to remove limescale.) Another method of filtration, chemical filtration, involves passing water through an active material that chemically removes impurities as they pass.
The most common household water filters use what is known as activated carbon granules (sometimes called activated carbon or AC) based on charcoal (a very porous form of charcoal, which is produced by burning something like wood with an ingestion reduced). oxygen). Charcoal is like a mixture between the graphite “lead” of a pencil and a sponge. It has a huge internal surface, full of nooks and crannies, which attract and trap chemical impurities through a process called adsorption (in which liquids or gases are trapped by solids or liquids). But while charcoal is excellent at removing many common impurities (including chlorine-based chemicals introduced during wastewater purification, some pesticides, and industrial solvents), it cannot withstand “hardness” (lime), heavy metals (Unless an activated carbon type of filter is used), sodium, nitrate, fluoride, or microbes. The main disadvantage of activated carbon is that the filters eventually become clogged with impurities and need to be replaced. This means there is an ongoing (and sometimes considerable) cost.