What type of particles do granular activated carbon filters primarily absorb?

Granular activated carbon (GAC) filters are designed to efficiently adsorb low molecular weight particles, particularly organic compounds. The structure of activated carbon provides a large surface area and porous structure, making it effective at trapping smaller molecules as they come in contact with the carbon.

This property is particularly beneficial in water treatment processes where the goal is to remove contaminants such as volatile organic compounds (VOCs), pesticides, and other similar pollutants that are often present in trace amounts and possess relatively low molecular weights. The nature of these low molecular weight particles allows them to fit into the micro-pores of the activated carbon, leading to effective adsorption.

In contrast, the other options focus on different types of substances that may not be as effectively removed by GAC filters. Heavy metals typically require different treatment methods, such as ion exchange or reverse osmosis. Solid waste involves larger particulate matter that is better managed through physical filtration methods rather than adsorption. Large hydrocarbons, while possibly having some interaction with activated carbon, may not be the primary focus of GAC filters, which excel at targeting smaller, readily soluble organic molecules.