Synthesis of millimeter-scale sponge Fe/Cu bimetallic particles removing TBBPA and insights of degradation mechanism

- S-Fe/Cu degrade TBBPA in aqueous solution effectively.
- Cu mass loading, pH and temperature were major influence factor on TBBPA degrading.
- DO facilitate the transformation of TBBPA in solution.
- Degradation pathways include debromination, hydroxyl, β-scission and O-methylation reactions.

Tetrabromobisphenol A (TBBPA) was a potential persistent organic pollutants. This study synthesized s-Fe/Cu bimetallic particles by decorated sponge iron (s-Fe) with Copper (Cu) to degrade TBBPA. S-Fe/Cu bimetallic particles was further characterized by XRD, XPS, SEM and EDS. The optimal TBBPA removal efficiency was 95.9%. Among the theoretical Cu mass loading increasing from 0 wt% to 6 wt%, 4 wt% mass loading was the best; with TBBPA initial concentration increased from 5 mg/L to 30 mg/L, TBBPA removal efficiency decreased from 91.2% to 73.0%; also, when dosage increased from 10 g/L to 30 g/L, removal efficiency increased from 58.1% to 95.9%; pH 6.5 were beneficial to degrading TBBPA and the s-Fe/Cu bimetallic particles showed strong catalytic ability after 4 reuse cycle. Kinetic analysis showed that the degradation of TBBPA obeyed pseudo-first-order kinetics. In addition, Liquid Chromatography Time-of-Flight Mass Spectrometry (LC/TOF/MS) detected degradation products including debromination products, hydroxylation products, single aromatic ring products and O-methylating product, which demonstrated that the main degradation pathway were debromination, hydroxyl, β-scission and O-methylation reactions.

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