Degradation of protocatechuic acid by two advanced oxidation processes: Ozone/UV radiation and H2O2/UV radiation

Two advanced oxidation processes: the combinations of ozone and UV radiation, and hydrogen peroxide and UV radiation, have been used in the chemical degradation of protocatechuic acid, a phenolic pollutant present in the wastewaters from olive oil manufacturing. In the first case, the kinetic study is carried out by taking into account the contributions of the single ozonation and the photochemical reaction and applying the film theory model. The apparent kinetic constants and reaction orders for the combined reaction are deduced and correlated as a function of pH and temperature. In the second case, an empirical reaction rate expression which considers the contribution of both oxidants, UV radiation and hydrogen peroxide, is proposed. The kinetic rate constants for this combined reaction are also obtained and correlated as a function of temperature and pH.