O 3 , O 3 /UV and O 3 /UV/ZnO for abatement of parabens in aqueous solutions: Effect of operational parameters and mineralization/biodegradability improvement

Methyl-, Ethyl-, Propyl-, Butyl-, & Benzyl-paraben degradation is investigated by combination of ZnO-based photo-catalysis and ozonation in a batch cylindrical photo-reactor to evaluate the influence of ZnO concentration, ozone dose, and pH. The results reveal that parabens removal increases by rising the ozone dosage up to 1.8 g/h and ZnO loading climb up to 1 g/L. Optimum pH value for parabens removal is 9, in 1 g/L of ZnO and 1.1 g/h of ozone dose in 20 min reaction time, which leads to complete removal of methyl-paraben by the combined photocatalytic ozonation (O 3 /UV/ZnO). © 2019 Institution of Chemical Engineer