Mechanistic investigation on degradation of tetrabromobisphenol S by OH, O3 and SO4•- in wastewater and atmosphere

Abstract

Listen

Translate article

Human cytotoxicity and neurotoxicity are two characteristics of the new brominated flame retardant (NBFR) tetrabromobisphenol S (TBBPS). TBBPS can be discovered in both water and the atmosphere. The degradation of TBBPS by •OH and O3 both in the atmosphere and water was investigated. For the first time, we examine the mechanism of TBBPS and O2•- transformation using the density functional theory (DFT) method. We also examine the routes of TBBPS with SO4•-, and 1O2. The TBBPS-OH intermediates will react with O2 and HO2• to produce products in water, and the •OH-addition products of TBBPS will react with O2 and NO in the atmosphere. In comparison to the water phase, the gas phase TBBPS pathways with •OH and O3 are more advantageous. At 298K, the TBBPS reaction rate constant with O2•- is 5.39 × 10-7M-1 s-1. The TBBPS O2•--addition routes are superior to the TBBPS O2•--SET pathways. SO4•- and •OH predominate in the breakdown of TBBPS, where O2•-, 1O2 and O3 playing a minor role. Significant quantities of very hazardous TBBPS breakdown products are produced by SO4•--based AOPs. TBBPS has an environmental half-life of 0.0119s within the [•OH] of 10-9molL-1 in AOPs at 298K, despite being environmentally persistent in natural waters. The majority of TBBPS transformation products have far lower levels of toxicity. This work disproved the theory that O2•--based AOPs degrade TBBPS and supported the degradation of TBBPS by AOPs based on •OH.