Kinetic Studies of n-Butylparaben Degradation in H2O2/UV System

This work reports the experimental results of kinetics study of n-butylparaben (BP) degradation in H2O2/UV systems. A pseudo-steady-state and competition kinetic approaches were used to determine the reaction rate constants between the BP and center dot OH. In competition kinetics atrazine (2.30 x 10(9) M-1.s(-1)) was used as a reference compound. The measured rate constants for center dot OH reaction with BP ranged from (3.84 +/- 0.12) x 10(9) M-1.s(-1) to (8.56 +/- 0.90) x 10(9) M-1.s(-1) depending on solution pH and temperature. Values of the rate constant obtained using different methods were in good agreement. The calculated activation energy was equal to 19.01 +/- 1.02 kJ mol(-1).