What is the primary goal of the activated sludge process?

The primary goal of the activated sludge process is to use microorganisms to decompose organic pollutants. This biological treatment method relies on a community of microorganisms that consume organic matter in wastewater, converting it into biomass and stable end products. During this process, aeration supplies oxygen, which is essential for the microorganisms to thrive and effectively break down organic pollutants.

The activated sludge process not only helps in reducing the concentration of dissolved and suspended organic materials, leading to cleaner effluent, but it also facilitates the removal of nutrients, such as nitrogen and phosphorus, which are often found in municipal wastewater. This process is crucial for ensuring that the water returned to the environment meets regulatory standards and does not harm aquatic ecosystems.

While the other options touch upon related aspects of wastewater treatment, they do not capture the primary purpose of the activated sludge process as effectively. For instance, creating biogas is a benefit of anaerobic digestion rather than the primary function of activated sludge. Filtering out heavy metals typically occurs in specialized treatment processes, and removing grit and debris is more aligned with preliminary treatment stages rather than the biological treatment focus of the activated sludge method.