Thermodynamics of Ion Exchange

We are investigating the effectiveness of Europa Water Service (EWS) resin to soften hard water by removing calcium (Ca²⁺) ions from distilled (DI) and tap water. The fundamental theory is based on ion exchange, where Ca²⁺ is exchanged for hydrogen (H⁺) ions and becomes stuck in the resin.

Evaluation is based on Ca²⁺ concentration, measured in mg/L using a Ca²⁺ selective electrode. The measurement range of the electrode is (1 to 40,000 mg/mL).

Ion-exchange resins may be relevant to chemical engineers through the use of water softening in heat exchangers, where hard water can result in mineral deposits that hinder heat transfer efficiency. Aside from Ca²⁺ ions, ion-exchange resins can remove similarly-charged ions, such as Mg²⁺.

Furthermore, the unique properties of ion-exchange resins serve useful in lanthanide extraction processes, where the extraction of lanthanide ions from rare earth solutions is essential for semiconductor manufacturing and MRI contrast agents.