Synthesis of metallic iron nanoparticles and their use in 4-chlorophenol dehalogenation

Herbicides are an important class of agrochemicals used for weed control. Organochloride herbicides show high toxicity and environmental persistence increasing the risk of soil and water contamination. Chlorophenols and their derivatives are toxic contaminants in the environment originated from degradation of agrochemicals. Metallic iron nanoparticles (Fe-NP) have been used for removal and degradation of a range of organic pollutants, including herbicides and organochlorides compounds. The aim of this work is to study the synthesis of Fe-NP and their application in 4-chlorophenol (4-CP) degradation. Fe-NP with average size of 100 nm composed of α-Fe phase were obtained through borohydride reduction. The Fe-NP were mixed with 500 μM of 4-CP at several pH values. The degradation of 4-CP was confirmed by monitoring the absorption band at 298 nm. Additionally, the phenol production was followed by reaction with monochloramine which produces a blue colored solution with maximum absorption at 680 nm. The decrease in absorbance in 298 nm suggest degradation of 4-CP. (author)