The reductive dehalogenation of brominated disinfection byproducts (DBPs) including bromoform and tribromoacetic acid (TBAA) by iron based bimetallic systems (Cu/Fe and Pd/Fe) was investigated. In Cu/Fe bimetallic system, only 8.1% of bromoform and 20.1% of TBAA were reduced within 20 min when the particle dosage was 5 g L−1, while 56.9% of bromoform and 62.7% of TBAA were removed in the same period when the dosage increased to 20 g L−1. A complete removal of bromoform and TBAA was achieved within 60 min of reaction in acidic conditions, while only 35.4% of bromoform and 10.8% of TBAA were removed after the whole experimental period (140 min) in alkaline conditions. Similar results were observed in a Pd/Fe bimetallic system. Bimetallic particles achieved high performance probably because galvanic cells were created between Fe (serving as an anode) and plating elements (serving as a cathode). This structure enhanced the reducibility of iron for reductive dehalogenation by facilitating iron corrosion as well as reducing the activation barrier of H2. The Pd/Fe system showed a better performance than Cu/Fe, which was attributed to a higher potential gradient (1.4 V) as compared to Cu/Fe couples (0.8 V). Furthermore, toxic assessment indicated that the toxicity of water samples had a dramatic decline after dehalogenation by bimetallic particles.
