Degradation of n-butylparaben and 4-tert-octylphenol in H sub(2)O sub(2)/UV system

The degradation of two endocrine disrupting compounds: n-butylparaben (BP) and 4-tert-octylphenol (OP) in the H sub(2)O sub(2)/UV system was studied. The effect of operating variables: initial hydrogen peroxide concentration, initial substrate concentration, pH of the reaction solution and photon fluency rate of radiation at 254 nm on reaction rate was investigated. The influence of hydroxyl radical scavengers, humic acid and nitrate anion on reaction course was also studied. A very weak scavenging effect during BP degradation was observed indicating reactions different from hydroxyl radical oxidation. The second-order rate constants of BP and OP with OH radicals were estimated to be 4.8x10 super(9) and 4.2x10 super(9) M super(-1) s super(-1), respectively. For BP the rate constant equal to 2.0x10 super(10) M super(-1) s super(-1)was also determined using water radiolysis as a source of hydroxyl radicals.