A new insight into the main mechanism of 2,4-dichlorophenol dechlorination by Fe/Ni nanoparticles

Three possible dechlorination mechanisms of chloroorganics by nanoscale zero-valent iron (n-ZVI) have been proposed and widely accepted, however, the main mechanism is still controversial and not verified by experimental results. In this study, 2,4-dichlorophenol (2,4-DCP) was selected as the target pollutant and the experiments were carried out for the screening of the main mechanism of 2,4-DCP dechlorination by n-ZVI and Fe/Ni nanoparticles (n-Fe/Ni). The results indicated that >95% of 2,4-DCP could be dechlorinated to phenol by n-Fe/Ni within 120 min, while 2,4-DCP could hardly be dechlorinated by n-ZVI particles. The active hydrogen atom (H*) that transformed from H2 under the catalysis of Ni was responsible for >90% of 2,4-DCP dechlorination by n-Fe/Ni and