The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers

强有力的证据表明，H2S的氧化铁（oxyhydr）氧化物也发生在地下水系统中，并可能发挥重要作用的硫和铁的循环，特别是在含水层中的电子和碳流。迄今为止，还没有进行系统的研究，可以定量评估其在这些系统中的意义。本项目旨在填补这一知识空白。反应的程度取决于矿物的反应性，我们假设可以表示在一个广义的动力学模型的整个pH范围内的环境relvance。该模型解释了H2S在较低pH值下和HS-在中性pH下吸附到中性氧化铁表面以形成反应性物种FeSH。反应性的变化可能是由内在因素引起的，如铁矿物的表面酸度和溶液组成，如离子强度和与其他离子的竞争。因此，本项目的总体目标是证明这种方法的有效性，以量化的动力学非生物厌氧H2S氧化铁（oxyhydr）氧化物，并阐明这一过程作为前体反应的作用，进一步微生物转化的含硫物质在含水层。

Strong evidence exists that the oxidation of H2S by ferric (oxyhydr)oxides occurs also in ground water systems and may exert a major role for the sulphur and iron cycle and in particular for the electron and carbon flow in aquifers. To date, no systematic study has been performed that allows to quantitatively assess its significance in such systems. This project aims to fill this gap of knowledge. The extent of the reaction depends on mineral reactivity, which we hypothesize can be expressed in terms of a generalized kinetic model for the full pH range of environmental relvance. This model accounts for the adsorption of H2S at lower pH values and of HS- at circumneutral pH to the neutral ferric (oxyhydr)oxide surface to form the reactive species FeSH. Variations in reactivity may be caused by intrinsic factors such as surface acidity of the iron mineral and solution composition, such as ionic strength and competition with other ions. The overall goals of this project therefore are to demonstrate the validity of this approach in order to quantify the kinetics for abiotic anaerobic H2S oxidation by ferric (oxyhydr)oxides, and to elucidate the role of this process as a precursor reaction for further microbial transformation of sulphur species in the aquifer.