Exploring the Affinity and Selectivity of Sedimentary Mackinawite (FeS) Towards Natural Organic Matter

This study aimed at studying the interactions between iron sulfides and organic carbon in hypoxic to anoxic sediments, focusing on St. Lawrence Estuary. The data provided here discussed the concentration profiles of different species in sediments pore waters sampled from different stations of St. Lawrence Estuary and Gulf. The capacity of synthetic iron sulfide toward sorption, here refers to adsorption and coprecipitation processes, was assessed through analyzing the thermodynamic isotherms after reaching the equilibrium in the presence of different concentrations of organic matter. The organic matter used in this study were extracted from different natural aquatic and terrestrial sources including plankton, corn, and soil .The effect of the organic matter sorption on the iron sulfide morphology was investigated through scanning electron microscopy. The colocalization between organic matter and iron sulfide was studied via synchrotron scanning transmission X-ray microscopy (STXM) coupled to near-edge X-ray absorption fine-edge structure (NEXAFS) spectroscopy revealed strong interactions between Fe-S minerals and NOM, specifically NOM extracted from plankton.

本研究旨在探究缺氧至厌氧沉积物中硫化铁与有机碳之间的相互作用，研究重点聚焦于圣劳伦斯河口（St. Lawrence Estuary）。本研究提供的数据集涵盖了从圣劳伦斯河口及海湾（St. Lawrence Estuary and Gulf）不同站位采集的沉积物孔隙水中各化学物种的浓度剖面。本研究针对合成硫化铁的吸附（sorption，本文特指吸附与共沉淀过程）能力展开评估，具体方式为分析不同浓度有机质存在条件下体系达到平衡后的热力学等温线。本研究所用的有机质提取自多种天然水生与陆生来源，包括浮游生物、玉米及土壤。本研究通过扫描电子显微镜（Scanning Electron Microscopy, SEM）探究了有机质吸附作用对硫化铁形貌的影响。本研究借助同步辐射扫描透射X射线显微镜（Synchrotron Scanning Transmission X-ray Microscopy, STXM）结合近边X射线吸收精细结构（Near-edge X-ray Absorption Fine Structure, NEXAFS）光谱技术，对有机质与硫化铁的共定位特征开展研究，结果表明铁硫矿物与天然有机质（Natural Organic Matter, NOM）之间存在较强相互作用，尤以从浮游生物中提取的天然有机质为显著。