What substance is commonly adsorbed by activated carbon due to its properties?

Activated carbon is widely recognized for its ability to adsorb a variety of organic compounds, particularly due to its large surface area and porous structure. Trihalomethanes, which are organic compounds that can form when chlorine reacts with natural organic matter in water, are commonly found in municipal water supplies. The adsorption process allows activated carbon to effectively remove these contaminants, making it an excellent choice for reducing levels of trihalomethanes in drinking water.

In contrast, while lead is a heavy metal and can be removed through other means such as ion exchange or reverse osmosis, it is not typically adsorbed by activated carbon. Nitrates, which are inorganic and highly soluble, do not effectively adhere to activated carbon surfaces either. Similarly, chlorine itself is a small, gaseous molecule that does not adsorb well onto activated carbon due to its chemical properties; instead, chlorine is often dechlorinated through chemical reactions rather than through adsorptive processes. Hence, the use of activated carbon is most effective for capturing trihalomethanes because of its affinity for organic compounds.