ADVANCED OXIDATION PROCESSES - A KINETIC-MODEL FOR THE OXIDATION OF 1,2-DIBROMO-3-CHLOROPROPANE IN WATER BY THE COMBINATION OF HYDROGEN-PEROXIDE AND UV-RADIATION

A kinetic model for the oxidation of organics in water by the combinat ion of hydrogen peroxide and UV radiation is described. The model is b ased on literature values for a series of reactions initiated by the p hotolysis of hydrogen peroxide by UV radiation into hydroxyl radicals, to which is added a term for the direct photolysis of the organic. Th e model is tested with data on the oxidation of a compound, 1,2-dibrom o-3-chloropropane (DBCP), at low levels (<500 mu g/L) in simulated and actual groundwater. The effect of the UV intensity, the initial conce ntration of hydrogen peroxide, and the various inorganic salts is inve stigated. Nitrate and bicarbonate/carbonate have a detrimental effect on the rate of oxidation of DBCP, the former due to UV shielding and t he latter due to (OH)-O-. scavenging. The rate of oxidation of DBCP is enhanced and the optimum peroxide level is lowered at low carbonate a lkalinity, suggesting that presoftening of groundwater prior to oxidat ion of halogenated alkanes should be cost-effective.