Reduction of Nitrobenzene by Four Sulfide Minerals: Kinetics, Products, andSolubility

摘要

Nitrobenzene was used as a molecular probe to study electron donor properties offour sulfide minerals. Nitrobenzene was selected as a probe because its reaction in aqueous systems has been well characterized. Suspensions of the four minerals were reacted with nitrobenzene under anaerobic conditions for various time periods. Nitrobenzene and its reaction products in both the solution and the solid phase were analyzed by liquid chromatography and UV-visible spectroscopy. The observed half-lives of nitrobenzene are 7.5, 40, 105, and 360 h, respectively, for reactions with sodium sulfide (Na2S0, alabandite (MnS), sphalerite (ZnS), and molybdenite (MoS2) under anaerobic conditions, at a 0.24 mol/L 1 water-mineral mixture concentration. The log plot of calculated sulfide ion concentration of minerals versus reaction half-life shows a linear relationship. Nitrobenzene reduction by sulfide minerals is a solution phenomenon. The sulfide mineral dissolution rate and its solubility, however, influence the reduction rate. (Copyright (c) 1992, ASA, CSSA, SSSA.)