Bisphenol-S (BPS) is a plasticizer that is being used as a replacement for bisphenol-A (BPA). Both compounds have been determined to be endocrine disrupting compounds; increasing use of BPS makes it necessary to understand its fate in wastewater treatment. As many pollutants are not removed from conventional wastewater treatment processes, there is a need to investigate the effectiveness of advanced treatment methods for the removal of contaminants. In this study, we examined the destruction of BPS with monochromatic low pressure UV irradiation (LP UV) and UV/H2O2 advanced oxidation (AOP). Experiments were conducted in buffered aqueous solutions and treated wastewater. The UV dose (fluence) delivered by the LP UV lamps was measured by Na2B4O7/KIO3 chemical actinometry. In all experiments, we irradiated all solutions at incremental UV doses up to 550 mJ/cm2. Irradiation of BPS solutions at the maximum UV fluence with LP UV removed 33% of the initial amount of BPS in buffered water and 30 % in treated wastewater. Additional experiments were conducted to examine the effect of UV/H2O2 AOP at H2O2 concentrations of 15, 50, and 100 mg/L in buffered water and treated wastewater. We observed first-order degradation kinetics in all experiments. The reaction rate constants observed in all experiments ranged from 3.9 × 10-5 s-1 for LP UV without H2O2 to 3.0 × 10-4 s-1 for the UV/H2O2 AOP in wastewater at H2O2 concentrations of 100 mg/L. Differences in the rate constants were attributed to scavenging of OH radicals and filtration of UV light by organic matter. In buffered water, the relative decrease of BPS ranged from 39 to 82%, and higher levels of degradation were observed at 15 mg/L H2O2. The highest decrease in BPS concentrations was observed in solutions containing 15 mg/L H2O2; higher levels of H2O2 did not show improvement. In treated wastewater, we observed 59-96% removal, with the highest removal observed at H2O2 concentrations of 100 mg/L. Higher levels of H2O2 are needed for effective removal in wastewater due to scavenging of OH radicals. We are currently determining OH radical reaction rate constants by isopropanol competition kinetics.

Photolysis and UV/H2O2 advanced oxidation processes of bisphenol-s in water

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.