Reductive Degradation of Tetrabromobisphenol Using Iron-Silver and Iron-Nickel Bimetallic Nanoparticles with Microwave Energy.

In this work, a novel combined system by Fe-Ag or Fe-Ni nanoparticles and microwave (MW) radiation were used for the debromination of tetrabromobisphenol A (TBBPA) in aqueous solutions. Core-shell structure bimetallic nanoparticles were prepared by replacement reaction in liquid phase and then characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques. MW radiation can enhance the degradation of TBBPA by Fe-Ag or Fe-Ni observably. The rate of reduction reactions for bimetallic nanoparticles under MW were first compared with those under conventional heating conditions. Compared with nano-iron, the deposition of Ag or Ni also accelerated the debromination, and Fe-Ag was more reactive than Fe-Ni toward TBBPA reduction. Removal efficiencies increased with increasing Fe-Ag dosage and MW energy level. Major reduction products of TBBPA identified by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) were tri-BBPA, di-BBPA, mono-BBPA, and BPA, which indicated a stepwise debromination process. It provides an effective technology for TBBPA laden wastewater treatment.