Having clean and purified water has become the golden standard for human daily consumption around the world. However, not everyone has access to the same privileges to clean water resources as the ones we have in the state of Washington, specifically in the Greater Seattle area. Water in most parts of the world has to be purified but just how do we purify water?
The entire purification process includes multiple stages that water must undergo to get rid of suspended solids, dirt, and other unwanted substances found in it. Today, I would like to focus on the most common method that Nature has taught us–Filtration.
When filtration is brought up, you may have some thoughts or vague images of how it works, but if you don’t here’s the best way to describe the process:
How Does Filtration Work?
Filtration is the process of physical separation that removes solids from water through a complex structure that allows water to get through . The medium of a filtration system varies a lot. It can be sand, clothes, membrane, and other filters which can be used to remove solids and undesired substances. The following figure is a simplified mechanism of water filtration.
As the picture illustrates, when water is flowing through the filter, the bigger particles are entrapped within the complex structure of the filter, and it allows only smaller particles to flow through. This method allows us to filter out pollutants and get clean water
In Nature, the soils act as a filtration system with multiple layers and sizes that allow particles to filter out, and this allows us to extract clean water from underground water deposits we know as aquifers. By observing how soil filters water naturally, we as humans have replicated this mechanism in order to build some of the filtration systems now found in our homes and communities making clean water more accessible to us all. The next few paragraphs will go more in-depth on how the filtration systems work in our homes and communities.
Filtration in Our Home
Water filtration is almost a must for every household, and the main purpose of water filtration in a household is to make water potable. Hence, a water filtration system has to equip with robust filters. There are multiple types of filters, such as the simplest activated carbon filter and the more complicated reverse osmosis system.
Because water quality varies from place to place, people may need different types of filtrations to get clean drinking water. For example, people living in the Seattle area get water almost directly from the rivers that flow through its mountains which makes its water quality decent. They may need the use of a boiler but this will be to remove any possible organisms that may have remained in the water or alternatively use an activated carbon filter to remove chlorine and odor.
Now let's take a look at how this differs on the other side of the world, my country people living in Taiwan are in the opposite situation that requires stronger and better filtration systems to clean our drinking water. The following graph can explain why:
Here is a comparison of the two filters, the one on right was only used for 6 months vs the left which is a brand new filter. Because of the high concentration of metals (i.e. iron, arsenic, etc. ) and sands found in our river and pipeline, almost every household in Taiwan needs a reverse osmosis filtration system in order to have potable water.
If I’ve piqued your interest in water quality, you may find some great resources by using the following keywords you can use on Google to get to know the quality of your local water and how water is transported from where it is collected to your home:
1) Water quality in [Region Name]
2) Clean Water Plan [Region Name]
3) Drinking Water Reservoirs [Region Name]
4) Water System [Region Name]
Filtration in Our Community
Unlike the water filtration for potable water in households, water filtrations in communities have a similar function but serve a different purpose which is to prevent pollutants from running into our ocean directly. The most common method is to leverage engineering and make our ground more penetrable by adding multiple layers of different sizes of materials. The following figure demonstrates the common stormwater filtration system.
As our previous articles discussed  , we pointed out different pollutants like nitrogen and synthetic substances that are threatening our ecosystem, especially aquatic environments. An efficient filtration system becomes extremely important when we are trying to pave roads for cars. Luckily, material scientists figured out pervious asphalt that can be used to increase filtration efficiency .
Although scientists and companies are hard at work trying to develop new and efficient solutions to treat water, the rapid growth of the human population and increase in water pollution has made it difficult for them to keep up with the output. Take one of the biggest counties in the state of Washington, they estimate that approximately 118 billion gallons of polluted stormwater don’t get treated because of lack of infrastructure and rapid population growth. This is serving as a negative consequence resulting in toxins reaching the Puget Sound thus threatening the aquatic lives such as Salmon .
Here are some helpful tips presented by King County (Washington State) that can help minimize the harm to our environment .
Stormwater pollution is one of the most difficult water sources to treat and manage, which is causing the most harm to the environment by bringing all kinds of pollutants to our oceans. Filtration is but the first among many steps in our efforts to clean our water and provide potable water for us and other forms of life. It’s up to us as habitants of this earth to take responsibility and own our future.