Effect of Ozonation on the Chlorine Demand of a Treated Surface Water and Some Macromolecular Compounds

The study described in this paper was conducted to examine the effects of ozonation and ozone-GAC filtration treatment steps on chlorine consumption of the Seine river water treated in the Choisy-le-Roi drinking water works. Ozone-GAC combined treatment was found to significantly reduce both the initial chlorine demand and the long-term chlorine demand of waters, excepting for waters sampled during cold months of the year. The removal of the chlorine demand potential by ozonation alone was found to be limited for the studied waters and for solutions of macromolecular compounds even in the presence of carbonate species. Ozonation carried out in the absence of bicarbonate ion was found to increase reactive sites with chlorine treatment of an aquatic fulvic extracted from the Seine river water.