Enhanced Degradation of Chlorobenzene in Aqueous Solution Using Microwave-Induced Zero-Valent Iron and Copper Particles

Microwaves were applied to reduce the activation energy of chlorobenzene in aqueous solution and enhance its removal using nano-scale zero-valent iron (Fe-0) or zero-valent copper (Cu-0) particles as dielectric media. When Fe-0 and Cu-0 particles absorb microwave energy, the electrical potential difference causes the metal electrons to rotate faster, thus producing more heat. The microwave-irradiated metal particles reduced the chlorobenzene activation energy by 6.1 kJ/mol (13.3 kJ/mol versus 19.4 kJ/mol) for Fe-0 and 5.4 kJ/mol (15.8 kJ/mol versus 21.4 kJ/mol) for Cu-0 and enhanced the chlorobenzene removal 4.1 times (82.8% versus 20.4%) for Fe-0 and 3.7 times (72.1% versus 19.5%) for Cu-0. The Fe-0 has a higher standard reduction potential than Cu-0; it is capable of removing more chlorobenzene than Cu-0 (82.8% versus 72.1%). Using the microwave-induced nano-scale iron or copper particle is effective in treating toxic organic substances, as demonstrated in this study. Water Environ. Res., 82, 642 (2010).