What type of treatment system typically utilizes a biosorption process?

A biosorption process is commonly used across various wastewater treatment systems to remove contaminants—particularly heavy metals and organic pollutants—by using biological materials. This process relies on microorganisms or organic material's ability to absorb and accumulate pollutants from wastewater.

In activated sludge systems, biosorption occurs as microorganisms, particularly bacteria, interact with contaminants in the mixed liquor. These microorganisms can absorb and breakdown various compounds, effectively utilizing the biosorption process as part of the treatment.

Trickling filters also leverage biosorption, as the biofilm that forms on the filter media retains microorganisms. As wastewater trickles over the biofilm, these microbes help remove contaminants through biosorption mechanisms.

Similarly, rotating biological contactors (RBCs) feature discs that support a biofilm. As the discs rotate through wastewater, the attached microorganisms engage in biosorption, contributing to the overall treatment process.

Since all of these systems can incorporate biosorption as a part of their treatment processes, the most accurate response is that biosorption is utilized in all of the provided systems.