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

Removal of Nitroaromatics from Synthetic Wastewater Using Two‐Step Zero‐Valent Iron Reduction and Peroxidase‐Catalyzed Oxidative Polymerization

“…Four different NACs were used in this study (nitrobenzene and o-, mand p-nitrotoluenes). Anaerobic conditions were necessary to achieve the complete reduction of the NACs to corresponding aniline (Agrawal and Tratnyek, 1996;Mantha et al, 2001a;and Monsef et al, 2000). Under these conditions, the overall reaction may be represented as follows:…”

“…In all previous works, groundwater has been the focus, with contaminant concentrations typically in the range of 20 to 50 M. Yet there is little literature on the application and potential uses of zero-valent iron to treat NACs at the concentrations found in industrial wastewater or process water, or the subsequent removal of the anilines formed. Efforts to address this issue began with a feasibility survey on the combined process (Monsef et al, 2000) and then a systematic investigation on the reduction of nitrobenzene (present in synthetic wastewater) to aniline (Mantha et al, 2001a). The present study continues this focus on industrial wastewaters containing NAC pollutants in the millimolar range.…”

“…Analysis. The concentration of the reaction products, anilines, was determined by reaction with trinitrobenzene sulfonate (TNBS test: Monsef et al [2000] and Mantha et al [2001a]). Colorimetric measurements are convenient for characterization of global removal or conversion of the starting aromatic compound.…”

“…The peroxidase-catalyzed oxidative polymerization transforms water-soluble organics into water-insoluble polymer. Nitroaromatics, even when they are phenolic or anilino compounds, are outside the scope of peroxidase catalysis (Monsef et al, 2000). The corresponding anilines are, however, excellent substrates for peroxidases.…”