A novel high-pH water treatment technology with processed dolomite as coagulant is proposed. The technology has been developed on the basis of laboratory-scale experiments with model solutions and a variety of natural water samples. Treatment effects are assessed in terms of colour, turbidity, TOC and COD removal. The technology is successful when applied to the treatment of surface water, irrespective of the influent concentration of pollutants. The effluent is clear and colourless, displaying a high removal of organic matter and heavy metals, as well as a partial inactivation of viruses and bacteria. Following a single-stage recarbonation process, water treated via this technology exerts no corrosive action. The optimum dolomite coagulant dose depends exclusively on the influent alkalinity, provided that turbidity level and colour concentration are moderately high. The optimum pH for the treatment process approaches 10.5. The technology proposed is an advantageous combination of three unit processes: decarbonation, coagulation and adsorption.

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