Home and Garden

Water Filtration: How Do They Work?

Water quality is difficult to determine with the naked eye. Several processes have been designed to test contamination levels. These processes may be physical, chemical, or biological tests. The most common parameters that determine water quality are organic and inorganic contaminants present. 

What are the Common Issues with Water?

Due to poor management of Agricultural, Urban, and Industrial wastewater, drinking water for human consumption has been at risk of being chemically contaminated or polluted. These contaminants are:

  • Pesticides and Herbicides which come from agricultural or urban activities
  • Inorganic contaminants, like minerals and salts coming from industrial or domestic wastewater discharges.
  • Organic Contaminants, such as volatile organic chemicals that are usually produced as by-products of petroleum industries, urban septic systems, or stormwater runoff.
  • Microbial contaminants, like bacteria and viruses, coming from sewage systems and or agricultural livestock. 

The physical and mechanical process of removing and reducing particulate matter concentration in water is called filtration. The filtration process also includes removing undesirable contaminants, suspended particles, parasites, algae, bacteria, viruses, and fungi. The filtration procedure will depend on the specific use of water, like using it as drinking water, pharmaceutical applications, or industrial use.

For household utilization, home water filtration systems have become popular, and there are several design options in the market. For potable water, experts in the water treatment field suggest choosing a countertop water filter. It is not only economical because of its features, but it also saves you the cost of getting commercial water from industrial manufacturers. To understand how these filter systems work, below are some helpful facts:

How Do Filters Work?

Physical and Chemical filtration are two methods to remove contaminants from water. Physical filtration means using a strainer to remove large impurities. Such filters may be a sieve, gauze, or a very fine membrane. Another method is chemical filtration that involves an active material where water passes through to remove such impurities. 

Water filters remove impurities from water such as particles, taste, odor, water hardness, and bacteria. This process yields safe drinking water with a better taste. There are four types of filters available for use, and these entail a combination of physical and chemical techniques. 

Activated carbon filtration

The most common water filters for household water filtration systems are known as activated carbon granules derived from charcoal. This filter type is a porous form of carbon produced from burning wood with a low supply of oxygen. Charcoal is a medium with a large surface area consisting of nooks where chemical impurities are trapped in a process called adsorption. 

In general, carbon filters are responsible for filtering large particles like silt and sediment. The surface attracts and absorbs these particles, so water from the faucet is already free from these impurities. Because of their absorption, water also tastes and smells better since charcoal works well with removing chlorine-based impurities.

Reverse Osmosis

To better understand drinking water quality, it will be best to learn about reverse osmosis. In common terms, reverse osmosis is a process that reduces contaminants in water. This is a great filtration method option mainly because of the level of protection it can give to your family. 

This process uses the principle of forcefully letting water pass through a semi-permeable membrane through high pressure, which then will allow water to pass through, leaving the contaminants filtered in the membrane. A reverse osmosis filter uses a 0.0001-micron pore size of the filter. It is effective in removing bacteria, protozoa, viruses, and chemical contaminants in water. 

Ion Exchange

This process is used to soften water, which means it involves the removal of limescale. It is designed to split apart atoms of a contaminant and convert them to ions. These ions are then trapped and released to another “good” ion. 

A basic water filter has a long column, filled with resin beads made from polymer that binds positively charged ions. The polymer beads bind calcium and magnesium than sodium, whereas the polymer is saturated with sodium ions, so this exchange of radicals happens thus, reducing hardness in water. 


Another known method to purify water is to let it boil, wherein the heat kills off bacteria but cannot remove hard compounds present in water such as limescale. Distillation, known as the oldest method to purify water, involves heating water at higher temperatures and separating impurities as the water vapor collected condenses, leaving impurities behind. While some contaminants boil at lower temperatures, they evaporate with the steam, and these impurities can not be removed by a distillation process. 

Overall, each one of these filter types caters to a specific water problem, and many filtration systems use a combination of these to achieve the desired water quality requirements.

What are Whole-house Filters vs. Under-sink and Counter Top Filters?

The point where water enters your home is referred to as the point of entry, where whole-house filters are usually staged. Water that passes through the main pipe before it enters your home will be filtered from this point. On the other hand, countertop and under sink water filters are a point of use water filters. These filter types are attached to a fixture, such as your sink faucet or a place in your home where you need water.

In conclusion, it is important to understand how water filtration works for you to determine which is appropriate for the water quality in your location. This varies significantly in every region all over the world. Water filters function to improve water taste and reduce the risk of drinking contaminated water. Bottled water may not be a better option than tap water since this is also not good for the environment. 

In addition, knowing how to maintain the water filter system can make your investment worth the money, It will prevent equipment damage and the water quality that you want to maintain will not degrade because of filter saturation. Some manufacturers usually place efficiency of water filters in their manuals, and maintenance procedures are indicated to make sure that filtration is effective. 


3 thoughts on “Water Filtration: How Do They Work?

  • Interesting post. We have well water so filtration is a MUST!

  • In our first home, we had a whole house filtration system to collect sediment from our well. We also did periodic water testing. We’re using an under the sink filtration system in our kitchen where we live now (in the city.) This improves the taste quite a bit.

  • Pingback: The Main Benefits of a Water Treatment System | Beautiful Touches

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