Enhanced Removal Of 2,4-chlorophenol By Heterogeneous Fenton Oxidation Using Iron Based Nanoparticles

In this study, various iron based nanoparticles were used to enhance Fenton oxidant for 2,4-dechlorophenol (2,4-DCP) degradation in aqueous solution. In order to reveals the mechanism of 2,4-DCP degradation in aqueous solution using oxidants such as H2O2 and Na2S2O8 (PS). To understand the mechanism of 2,4-DCP degradation in heterogeneous Fenton-like system, nanoscales zero-valent iron (nZVI) as the catalyst was characterized by various techniques, and the parameters impacting on the 2,4-DCP degradation were investigated. A higher dechlorination of 2,4-DCP using n-Fe/Ni, n-Fe/Pd was observed. However, nZVI was the best catalyst to enhance oxidation of 2,4-DCP. This indicates that nZVI improved the degradation fo 2,4-DCP in Fenton-like system, where included both the reductive declorination and Fenton oxidation. The results from nZVI characterization proved that the corrosion of nZVI and Fe2+ act as a source to generate free radicals. It was also found that the pH values, concentration of oxidant, nZVI dosage and concentration of 2,4-DCP significantly impacted on the degradation of 2,4-DCP. In addition, the process of 2,4-DCP degradation by nZVI/H2O2 system was a diffusion-controlled reaction and fits well with the pseudo first-order kinetic model, while a chemical control reaction was observed in nZVI/PS system, where less than 40% of COD was removed by oxidants (H2O2, PS) due to nZVI enchancement.A low COD was removed in degradation of 2,4-DCP using nZVI/H2O2 system, which can be attributed to the low solubility of 2,4-DCP. To address this inssue, various organic bentonic supported nZVI were synthesized and used as a catalyst to degrade 2,4-DCP. To understand the functions of nZVI/DKl, the n-Fe/DK1 was characterized by SEM, EDS andXRD, while the effect of parameters on 2,4-DCP degradation were investigated. The values of COD and the reuse of n-Fe/DK1 were tested. The results show that 78.6 COD in the degradation of 2,4-DCP was removed since the adsorption of 2,4-DCP onto the DK1, and subsequently reductive dechlorination and Fention-like oxidation of 2,4-DCP. More than 90% of 2,4-DCP was removed after n-Fe/DK1 reusing 7 times. This indicates that n-Fe/DK1 is a functional nanomaterial and a potential for the remedation of a low solubility of orbaic contaminants.