Heterogeneous photodegradation of bisphenol A and ecotoxicological evaluation post treatment

Abstract

Bisphenol A (BPA) is an emerging pollutant with endocrine disrupting properties that can be found at trace levels in various aqueous environments. Conventional water and wastewater treatments are not designed to efficiently remove these substances. Therefore, this work investigates the removal of BPA by an Advanced Oxidation Process (AOP), specifically heterogeneous photocatalysis using TiO2. The influences of the TiO2 concentration (1.0–10.0 mg L-1), pH (5.3 and 8.5) and effects matrix composition were studied for the removal of BPA at a concentration of 0.8 mg L-1. The results indicated that BPA was completely removed after 45 min of treatment using 7.5 and 10 mg L-1 of TiO2, under constant aeration and artificial UV irradiation, at the different pH values. The use of solar radiation as an UV source was also effective, removing BPA after 60 min of irradiation at pH without adjustment, as well as at pH 8.5. Ecotoxicological evaluation indicated that the post-treatment samples did not present acute effects towards Daphnia similis. Evaluation of chronic toxicity with Raphidocelis subcapitata showed that there was a reduction in the negative effect of BPA under the growth rate of algae biomass after 60 min of treatment, compared to the initial sample.