Conclusion

Thanks to sophisticated plant construction and regeneration techniques and a judicious combination of resins, ion exchange can produce demineralized water of a quality very close to that of chemically pure water, better than that obtained by distillation. In many cases, the chemical efficiency of regeneration is close to the stoichiometric value.

Most of the improvements to plant structure were made in the 1970s and 1980s, and today it's mainly the servo and computer control systems that are being improved.

Once the discontinuous, cyclic mode of operation inherent in the unitary ion exchange process has been accepted, the main criticism that can be levelled at this process is the consumption of chemicals required for resin regeneration. However, given that ion exchange is mainly applied to the treatment of dilute solutions, leading to long...