Highly efficient removal of tetrabromobisphenol A by Fenton degradation with iron-modulated zeolite under nanoconfinement

Abstract

As the most commonly used flame retardant, the mass production and use of TBBPA have caused extensive environmental pollution, and its green and efficient degradation was a key challenge for current research. Hence, we synthesized a pure silica-based Mobilization Filter (MFI) molecular sieve doped with Fe atoms (Fe@S-1) for peroxydisulfate (PDS)-activated degradation of TBBPA. The Fe@S-1/PDS system showed excellent removal efficiencies for TBBPA with removal ratios ranging 98.9 % and k values 0.497 min−1. Characterization analysis proved that the Fe@S-1 have mesoporous structures with intergranular and intragranular interconnections with nanoconfinement effect, the in situ incorporation through the synthesis process of abundant highly dispersed and valency-controlled framework Fe(II)/(III) species can achieved rapid activation of free radicals. In the spatial confinement mediated fenton-like reaction system, the enhanced utilization of oxidative free radicals and also exhibited remarkably higher reaction kinetics (6.05 times faster) toward TBBPA than its nonconfined analog. In addition, the catalyst showed good catalytic stability in the cyclability test, no significant loss of activity and minimal metal leaching were shown in a 96 h run. Finally, TBBPA degradation capacity of the catalyst was evaluated under the influence of common anions and in the actual water body and the possible degradation pathways of TBBPA were proposed. This work provided a new idea for the design of structurally doped catalysts for TBBPA degradation.