Final answer:
Trickling filters in wastewater treatment processes are classified as fixed film treatment methods. They involve the growth of microorganisms on a fixed surface that forms a biofilm, which helps in the decomposition of organic matter in the wastewater.
Step-by-step explanation:
Trickling filters are classified as a type of biological treatment method in wastewater treatment processes. They are considered fixed film treatment methods because the treatment process involves the growth of microorganisms on a fixed surface, such as rocks or plastic media, that forms a biofilm. The biofilm provides a surface for the microorganisms to attach to and creates a favorable environment for the decomposition of organic matter present in the wastewater.
The trickling filter process consists of wastewater being distributed over the fixed bed of media, allowing the wastewater to trickle down through the media. As the wastewater flows over the biofilm, the microorganisms present in the biofilm consume and break down the organic matter, converting it into simpler and less harmful substances.
The key distinction of trickling filters as fixed film treatment methods is that the microorganisms responsible for the treatment are attached to a solid surface rather than freely suspended in the wastewater. This allows for a more stable and efficient treatment process, as the biofilm provides a protected environment for the microorganisms and allows for a longer contact time between the microorganisms and the wastewater.