The Basics of Filters and Water Treatments: Charcoal

Food and drink are two of the basic necessities of human survival. Across the ages there has been a need for healthy and clean sources of hydration. Whether for cleaning contaminated sources or for removing unwanted minerals, water treatments have become an important technology that has advanced in recent years. Much of the technology used in the filters in these systems today is based on a material that can be found in most households- charcoal.

Charcoal is a form of carbon, one of the most common elements on Earth. Carbon is one of the main building blocks of life, so it is easily found in plants and animals. Charcoal does dehydrating some sort of plant make a carbon substance or animal remains. Traditionally this has been done through the heating of wood in a closed environment that allows for no air to enter. This produces the charcoal without burning the carbon away. In recent years new processes have been developed that use other substances like sugars.

In order to use charcoal in water treatment processes, it needs to first be activated. Activated charcoal can be made using a similar technique to making regular charcoal. Heat is applied to charcoal that is exposed to reactive gases to activate it using this process. Most often, though, it is exposed to chemicals that eat away at the carbon. Depending on the method used, this material can take several forms. Most often the activated carbon takes a powder-like form, though it can be produced in solid chunks for certain applications.

During the activation process the carbon is eroded on a molecular level. Instead of solid chunks of carbon, the charcoal becomes porous and is covered with tiny holes and rough surfaces. This lends the material most of its useful properties. Because carbon reacts well with many different elements, it is useful for filters, and the porous material gives it a large surface area. This allows gases and liquids to interact more with the carbon.

These granules of activated carbon are used in air and water treatments. To purify gases and liquids, they are passed through pipes filled with the carbon. While passing through, the liquid or gas enters the tiny crevices in the material. During this time, any impurities come into contact with the carbon and undergo adsorption. This is a chemical reaction that bonds the unwanted particles to the carbon molecules while the liquid or gas flows through unaffected.

Filters used for air and water treatments need to be replaced from time to time. After a while of use they become saturated with filtered particles and are no longer as effective. How long these filters last depend on the type of activated carbon used and the amount of filtering being done. In industrial applications these factors are closely monitored and accounted for. Filters for home use typically have a recommended expiration date based on an average use rate.

Thankfully, carbon is a readily available substance and is easy to activate, making water treatment a useful and effective practice.