Kinetics of dolomite dissolution in a packed bed by acidified desalinated water

• Critical review of published data on dolomite dissolution by acidified water
• Theoretical modeling and experimental confirmation of dolomite acid dissolution
• Acid strength found to be also a parameter governing the dissolution mass transfer coefficient
• Dolomite dissolution is a viable process for re-mineralization of desalinated water.

A post treatment process commonly applied in water desalination practice serves to introduce calcium and carbonate alkalinity to the water in order to protect the distribution system from corrosion damage. Addition of magnesium ions also is currently under consideration. Dolomite is a double salt of CaCO3 and MgCO3 and its dissolution by acidified desalinated water is of interest as this could serve to provide calcium, magnesium and carbonate alkalinity in a single re-mineralization operation. A critical literature review highlights the limitations of published data on dolomite dissolution and in particular their inadequacy for predicting dissolution in industrial equipment. The present study examines the kinetics of re-mineralization of acidified desalinated water in continuous flow over a packed bed of dolomite grains. A kinetic model based on mass transfer control is presented and shown to be in excellent agreement with experimental data. Results of this study indicate that dolomite dissolution is a viable process for re-mineralization of desalinated water.