What does chelation refer to?

Chelation refers to the chemical process in which metallic ions, such as those of heavy metals, are bound to organic compounds through the formation of stable complexes. This process is particularly important because it prevents the precipitation of metals, such as copper, that can occur in water systems due to changes in pH or the presence of other chemicals. By chelating these metallic ions, the organic compounds effectively "safeguard" the metals in solution, thereby enhancing their solubility and bioavailability while also reducing their potential toxicity. This aspect of chelation is especially relevant in water treatment, where controlling metal ion concentration is crucial for maintaining water quality and safety for consumption.

The other options do not accurately capture the definition of chelation. For instance, bonding metallic ions with salts does not provide the same stability and protective qualities as chelation. Similarly, acidifying water does not synonymously imply chelation, and the addition of minerals to improve water quality is a different practice that may not involve the complexation of metals at all.