What is the primary purpose of trickling filters in wastewater treatment?

The primary purpose of trickling filters in wastewater treatment is to facilitate biological treatment. Trickling filters are designed to promote the growth of microorganisms on a media surface, which then metabolize organic pollutants present in the wastewater. As the wastewater trickles over the media, which could consist of stones, plastic or other materials, the microorganisms, often referred to as biofilm, utilize the organic matter as a food source, effectively reducing the concentration of pollutants in the effluent.

While trickling filters do contribute to aeration by allowing oxygen to come in contact with the wastewater as it flows over the media, the main objective is to support the biological processes necessary for treating the wastewater. The removal of nitrogen and elimination of pathogens can be secondary benefits, but they are not the primary role of trickling filters in wastewater treatment. The focus remains on harnessing biological processes to break down contaminants efficiently.