AWWA WQTC65834

The objective of this powerpoint presentation was to determine if electrolysis and volatilization can be an effective technique for reducing the concentration of bromide in California State Project Water resulting in reduced formation of bromate when ozonated. The hypothesis presented is that bromide can be electrolyzed to bromine and bromine can be volatilized at low pH (<3.5) and air stripping with fine gas, producing a finished water with a lower bromide concentration and less potential to form bromate when ozonated. Reasons for removing bromide are listed, along with current bromide treatments. An overview of electrolysis and volatilization is provided that includes: electrolysis and hydrolysis; electrolysis reactor; analytical techniques; Experiment 1 - Bromide Removal as Impacted by Flow and Current; Experiment 2 - Bromide Removal by Depth; and, Experiment 3 - Electrolysis and Ozonation, A, B and C. Overall conclusions were that: the oxidation and volatilization of bromide does lower the concentration of bromide in drinking waters; removing bromide from water prior to ozonation can reduce the formation of bromate under the right conditions; and, the DPD-FAS titration technique for Cl₂ does appear to be adequate for electrolyzed waters. Includes tables, figures.