Recarbonization of drinking water in fluidized-bed reactor

Investigation of drinking-water recarbonization process is the main aim of this work. Experiments aimed at increasing of Ca2+ and Mg2+ in water were carried out in laboratory scale fluidized-bed reactor. This technique offers potential for increasing of reaction surface area and overall reaction rate, and represents a new approach in drinking-water industry. Measurements of hydraulic characteristics of the fluidized bed were performed. The results of comparison of two different recarbonization agents, dolomite and half-calcined dolomite, show that half-calcined dolomite is more efficient for increasing concentration of Ca2+ and Mg2+ from value below the recommended limit to 3.4 mmol L-1. Effect of carbon dioxide on enrichment of water by calcium and magnesium was also investigated and positive effect was observed. Concentration of Ca2+ and Mg2+ with CO2 present was increased by factor 2.6 in comparison without addition of CO2 to the system at the same conditions. The use of fluidized-bed reactor resulted in significantly higher remineralization rate in comparison with static filtration column.