Removal of Nitroaromatic Compounds from Water through Combined Zero-valent Metal Reduction and Enzyme-based Oxidative Coupling Reactions

Peroxiduse-catalyzed oxidative coupling, previously shown to be an effective strategy for removal of phenols from water, has been optimized for analogous reaction and removal of several anilines. Nitroaromatic compounds, even when they are phenolic or anilino compounds, are outside the scope of peroxidase catalysis. However, zero-valent iron has been found effective in conversion of aqueous nitrobenzene to aniline, quickly and quantitatively in the 0.5 to 10mM concentration range in the absence of oxygen. The sequential application of these two steps, zero-valent iron reduction followed by peroxidase-catalyzed oxidative coupling, to nitrobenzene and preliminary results in the development of a continuous flow system for removal of nitrobenzene from water are presented.