Final answer:
Ion-exchange chromatography de-ionizes water by passing it through a column containing ion-exchange resins, substituting undesirable ions like Ca2+ and Mg2+ with Na+. While the water is softened, the increased sodium content may be a concern for some individuals. Chemical engineers design such systems, considering both effectiveness and health implications.
Step-by-step explanation:
To use ion-exchange chromatography to de-ionize water, a process commonly referred to simply as ion exchange is applied. This involves passing water through a column containing ion-exchange resins, which are substances capable of exchanging ions with those dissolved in water. Typically, the goal is to remove hard water ions like calcium (Ca2+) and magnesium (Mg2+) by replacing them with sodium ions (Na+).
This specific application comes with a potential health consideration; softened water has higher sodium content, which may not be suitable for individuals on sodium-restricted diets. Chemical engineers often deal with such water treatment processes and aim to design systems that balance effectiveness and safety.
Though ion-exchange is effective for water softening, in some settings, other methods like reverse osmosis or flash evaporation are preferred for water desalination due to different reactivity in ion-exchange reactions, such as when sodium hydroxide and hydrogen chloride react to form sodium chloride and water.