Removal of parabens from water by UV-driven advanced oxidation processes

[Display omitted] •Effectiveness of UV radiation on the degradation of 3 common-use parabens was studied.•The highest photodegradation was related to the alkyl chain length and ΔELUMO-HOMO.•The performance of different UV radiation-based AOPs was investigated.•Three mechanisms: de-esterification, hydroxylation, and decomposition are involved.•None of the identified degradation by-products were cytotoxic. This study analyzed the degradation by direct photolysis with UV radiation of three common-use parabens (methylparaben, MetP, ethylparaben, EtP, and butylparaben, ButP) that have been detected in different types of water. The effect of different operating variables on their degradation by UV radiation was determined. A correlation between the degradation rate constant and the energy difference between the LUMO and HOMO orbitals of the parabens was established. A further study objective was to establish the effectiveness of different advanced oxidation processes in EtP removal from water. Rate constant values increased in the order MetP