Activated carbon starts with an organic material with a high carbon content, such as coal or wood. The material is slowly heated in a high-temperature, low-oxygen environment that is not allowed to burn. Instead, the material dries, releasing impurities as well as water. The resulting product is called char.
Next, the char goes through a variety of chemical and physical processes that greatly increase its surface area and create a network of fine pores. Carbon molecules naturally attract and bind to a wide variety of chemical compounds, and the large amount of surface area provides ample molecular binding sites.
Depending on the application, activated carbon can be used alone or impregnated with chemicals that enhance its ability to bind to target compounds. Impregnation can help improve its effectiveness against a wider variety of impurities and toxic substances.
Activated Carbon in Water Purification
Activated carbon is used at multiple levels in the water treatment process. It is used to filter potable drinking water at both the home consumer and municipal level, removing contaminants such as organic matter, pesticides, and herbicides.
Activated carbon also plays an important role in treating industrial wastewater.
In this application, activated carbon removes dangerous organic and noxious odor-causing substances, returning the waste to a safe state before disposal or reuse. It is often part of a multi-treatment approach to ensure groundwater protection.
Activated Carbon Air Purification
Activated carbon is used to purify the air in many important ways. One example of an industrial use is cleaning biogas that is a byproduct of the natural decomposition process. They tend to collect toxic organic volatile organic compounds (VOCs) and other byproducts around landfills, dairy farms, and similar places, such as those produced by the degradation of shampoo in landfills.
At home, activated carbon protects against VOCs released by paints, cleaning products, refrigerants, and other household products, as well as irritants produced by cooking fumes. Activated carbon air filters are particularly useful for those who suffer from allergies and asthma because they eliminate many common environmental triggers.
