Flocculation serves what main purpose in water treatment?

Flocculation serves the main purpose of forming aggregates to remove impurities from water during the treatment process. This is a critical step in water purification, particularly in the coagulation and flocculation stages. In this process, chemicals, known as coagulants, are added to water to destabilize suspended particles, allowing them to clump together into larger particles called flocs.

These flocs can then be more easily separated from the water, usually through sedimentation or filtration. This step significantly improves water quality by removing a range of contaminants, including suspended solids, some pathogens, and other impurities that might be present in the source water. Effective flocculation is essential for achieving the clarity and quality standards required for safe drinking water.

The other options focus on different aspects of water treatment that do not directly relate to the flocculation process. For instance, preventing bacterial growth is usually handled through disinfection processes, while dissolved oxygen levels are maintained for aquatic health rather than removed. Therefore, the focus on aggregate formation to eliminate impurities clearly highlights the primary function of flocculation in water treatment.