Abiotic reduction of p-chloronitrobenzene by sulfate green rust: influence factors, products and mechanism

Abstract

The reduction of p-chloronitrobenzene (p-CNB) by sulfate green rust (GR_SO4) was systematically studied. The results revealed that GR_SO4 has a good removal effect on p-CNB. The removal efficiencies of p-CNB by GR_SO4 improved with the increase of the pH value. The removal efficiencies in the presence of ions were better than that of GR_SO4 alone, while natural organic matter (NOM) could adsorb p-CNB, which competed with GR_SO4. The reductions of p-CNB by GR_SO4 under different conditions followed pseudo-first-order reaction kinetics except for the reactions in the presence of NOM. p-CNB was converted into p-chloroaniline (p-CAN), which produced p-nitrosochlorobenzene and p-chlorophenylhydroxylamine as the intermediate products. The results of the X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed GR_SO4 was gradually transformed into goethite. Fe(II) in the GR_SO4 structure was the main electron donor involved in the reaction.