State-of-the-art review on post-treatment technologies

Desalinated waters are poor in minerals thus, a certain degree of re-mineralization is essential so as to make the water palatable and non-corrosive as well as to meet health requirement. Selection of re-mineralization process is determined by regulatory water quality standards. This review summarizes alternative post-treatment practices aimed to introduce calcium, carbonate alkalinity and magnesium to desalinated water with emphasis on kinetic design models. Among the methods discussed are: blending with source water, direct dosage of chemicals, limestone, dolomite and magnesium oxide dissolution, ion exchange and a novel micronized limestone dissolution process. Finally, cost evaluations of various re-mineralization alternatives are presented. © 2014 Elsevier B.V. All rights reserved.

A detailed review of post-treatment hardening indicates that there are well established processes whose advantages and drawbacks are well defined. The key features that deserve research and development efforts are establishing more confident correlations for the kinetics dissolution coefficients as function of governing parameters. It would also be useful to explore in more details some of the minor studied processes such as hardening by dolomite contactors and micronized powder. Acknowledgment Thanks are due to the Israel Water Authority for funding part of our post-treatment research projects. Some of the recent kinetic data presented in this paper originate from M.Sc. research of L. Fine, R. Scwartz and M. Greiserman.