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 nanoscale zero-valent iron (Fe⁰) or zero-valent copper (Cu⁰) particles as dielectric media. When Fe⁰ and Cu⁰ 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 Fe⁰ and 5.4 kJ/mol (15.8 kJ/mol versus 21.4 kJ/mol) for Cu⁰ and enhanced the chlorobenzene removal 4.1 times (82.8% versus 20.4%) for Fe⁰ and 3.7 times (72.1% versus 19.5%) for Cu ⁰. The Fe⁰ has a higher standard reduction potential than Cu⁰; it is capable of removing more chlorobenzene than Cu⁰ (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.