Palladium nanoparticles facilitated fast debromination and complete mineralization of Tetrabromobisphenol S (TBBPS) through coupling catalytic hydrodehalogenation with advanced oxidation processes

Abstract

Brominated organic pollutants (BOPs), classified as persistent organic pollutants (POPs), have raised environmental concerns due to the stability and toxicity. This study employed an innovative technology, involving the coupling of in situ catalytic hydrodehalogenation (HDH) with advanced oxidation process (AOP) facilitated by palladium nanoparticles (PdNPs), for the removal and mineralization of Tetrabromobisphenol S (TBBPS). The heterogeneous catalytic HDH over PdNPs achieved a TBBPS conversion to bisphenol S (BPS) with a debromination efficiency of nearly 99% in 1 h under near-neutral conditions. Additionally, the in situ generated Br⁻ and PdNPs synergistically promoted the mineralization removal of BPS during the AOP (over 99% removal within 20 min). Further analysis showed that ¹O₂ produced by activated peroxymonosulfate (PMS) was the most effective active substance for degrading BPS in this system, surpassing other active substances (·OH, SO₄·⁻, and O₂·⁻). Combining experimental data and theoretical calculation analysis, a plausible degradation pathway for TBBPS was proposed. ECOSAR prediction indicated that the coupling method substantially diminishes the biotoxicity of the substrates through debromination and mineralization. These findings substantiate a promising coupling method that addresses the limitations of using catalytic reduction and AOP individually, offering new perspectives on the remediation of halogenated organic pollutants.