Which statement regarding trickling filters is true?

In the context of wastewater treatment, trickling filters function primarily to promote aerobic treatment of wastewater. The correct statement is that they enhance aerobic treatment. Trickling filters consist of a bed of coarse material, such as rocks, plastic media, or other materials that provide a surface for biofilms to develop. These biofilms consist of microorganisms that biodegrade organic contaminants present in wastewater.

As the wastewater trickles over these filter media, it allows for maximum contact between the wastewater and the microorganisms in the biofilm, facilitating aerobic decomposition. This process is efficient in removing organic matter, nutrients, and pathogens from the wastewater stream. While trickling filters can aid in removing some particulate solids, their primary role is not to serve as a straining mechanism for organic matter but to provide a biological treatment process that enhances the overall quality of the effluent by utilizing aerobic processes.

The other options do not accurately reflect the function of trickling filters. They do not operate exclusively under anaerobic conditions, they are designed to function effectively across various flow conditions rather than just low flow, and their main purpose is not solely to strain out organic matter.