Enhanced degradation of tetrabromobisphenol A by Fe3+/sulfite process under simulated sunlight irradiation

Degradation of tetrabromobisphenol A (TBBPA), an emerging micropollutant, by photo/Fe3+/sulfite process was investigated under different operational conditions and water matrices. 91% of TBBPA was efficiently degraded within 30 min in the Fe3+/sulfite system under sunlight irradiation when the initial pH was 6.0, which is much higher than that of TBBPA without irradiation (52%). The acceleration of radical generation and direct photolysis by photo irradiation were responsible for the enhanced TBBPA degradation. Although this process showed better performance on TBBPA degradation in weak acid conditions, the high removal efficiency was also achieved at near-neutral pH. HO center dot, SO4 center dot- and direct photolysis contributed to TBBPA degradation. Direct photolysis and SO4 center dot- presented the dominant contribution. The degradation rate increased with elevating the Fe3+ dose (10-40 mu M), but slightly decreased when the Fe3+ dose was further raised to 100 mu M. Similarly, the degradation efficiency initially increased with increasing the sulfite dose (100-400 mu M), but decreased when the sulfite concentration reached 1000 mu M. Dissolved oxygen played a crucial role in TBBPA degradation, the presence of water matrices such as humic acid (0.8-4.0 mg/L), bicarbonate (0.5-10 mM) and chloride (0.5-10 mM) retarded TBBPA degradation. This study proposed a new efficient strategy to enhance TBBPA degradation in the Fe3+/sulfite process.

Automated summary

The study showed that TBBPA degradation was enhanced by photo irradiation in the Fe3+/sulfite process. Better degradation performance was observed under weak acid conditions, but high removal efficiency was also achieved at near-neutral pH.