Iron based bimetallic nanoparticles to activate peroxygens

Recently, metal nanoparticles have been used to generate highly reactive free radicals from peroxygens to treat hazardous organic compounds. A novel method of treating trichloroethylene (TCE) was applied using bimetallic zero valent nanoparticles (BZVNs) and peroxygens. In the investigation of nine different BZVNs as activators, the highest TCE oxidation was achieved by nano-Pd-Fe-0 and nano-Zn-Fe-0 in the activated persulfate system, nano-Co-Fe-0 in the activated peroxymonosulfate system, and nano-Ag-Fe-0 in the activated hydrogen peroxide system. In all three systems, increasing the dosage of metal nanoparticles and peroxygens increased the oxidation of TCE. We also found that BZVNs are promising activators for hydrogen peroxide, persulfate, and peroxymonosulfate compared to monometallic zero valent nanoparticles. For example, the TCE reaction rate constant by nano-Ag-Fe-0 activated H2O2 is 9- to 18-fold higher than that for nano-Fe-0 activated H2O2. The activated H2O2 system showed a much lower TCE oxidation rate compared to either activated persulfate or activated peroxymonosulfate, suggesting that a bridged group complex is formed between the activators and H2O2, causing a lower TCE oxidation rate. (C) 2013 Elsevier B.V. All rights reserved.