What process results in the formation of insoluble solids that settle out of water?

The process that results in the formation of insoluble solids that settle out of water is coagulation. Coagulation involves the addition of chemical agents, known as coagulants, to water, which neutralizes the charge on suspended colloidal particles. As these particles lose their charge, they begin to clump together, forming larger aggregates or flakes. These aggregates, known as flocs, then become heavy enough to settle out of the water due to gravity.

Coagulation is typically one of the initial steps in water treatment processes aimed at removing turbidity and suspended solids. It is crucial for clarifying water, as it minimizes the quantity of particulates that will need to be filtered out later in the treatment process.

Flocculation is a subsequent step that involves the gentle mixing of the water to encourage the growth of these aggregates. Oxidation, on the other hand, is a chemical process used for different purposes such as disinfection or removal of specific contaminants, while filtration is a physical process used to separate solids from liquids after coagulation and flocculation have occurred.