What does a milky or bluish tint during flocculation suggest?

A milky or bluish tint during flocculation typically indicates the presence of an excessive amount of coagulant, such as alum. When too much alum is added to the water treatment process, it can lead to the formation of larger, unstable aggregates or flocs. This lack of stability results in the scattered light reflecting off the particles, producing a milky or bluish appearance in the water.

In proper flocculation, the process aims to achieve the right balance where the coagulating agent effectively binds particles together without excess that compromises the process. Observing this color often means that the dosing needs to be adjusted to optimize the flocculation process, ensuring clearer water and more effective removal of impurities.