黄铁矿氧化产活性氧及其地球化学效应  

The reactive oxygen species produced by the oxidation of pyrite and its geochemical effects

作　　者：黄娥 蒋燕虹 李亚欢 鲜海洋[1,2] 梁晓亮 HUANG E;JIANG Yanhong;LI Yahuan;XIAN Haiyang;LIANG Xiaoliang(Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Minera Physics and Material Research&Development,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou Guangdong 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《矿物学报》2024年第5期728-739,共12页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:42372048)。

摘　　要：黄铁矿是地壳中分布最广泛的硫化物矿物,其氧化过程产生多种活性氧物种,对环境物质转化和污染物衰减具有重要作用。本文系统总结了黄铁矿氧化产活性氧的反应机制、影响因素以及地球化学效应。在酸性、缺氧条件下,表面硫缺陷位Fe^(3+)氧化吸附态H_(2)O是产·OH的主要机制;而在有氧条件下,黄铁矿表面Fe(Ⅱ)与O_(2)反应生成吸附态H_(2)O_(2),后者通过非均相/均相Fenton反应产生·OH。在光照条件下,作为半导体矿物的黄铁矿产生光生空穴和电子,促进活性氧物种的产生。黄铁矿氧化产活性氧活性具有晶面选择性,受其结构中的类质同象置换、环境中的共存物质所影响。黄铁矿氧化产活性氧很可能是早期地球氧化驱动力来源之一,对全球陆-海硫通量增加以及条带状铁矿的形成具有重要影响,还对环境中的重金属和有机污染物的迁移和归趋具有重要的控制作用。未来相关研究需重点关注以下方面:均相/非均相反应以及各活性氧物种在氧化反应中的贡献;置换离子种类及微观局域环境对黄铁矿氧化活性氧反应性的影响;反应过程中黄铁矿表面微结构的变化。Pyrite is the most widely distributed sulfide mineral in the earth′s crust.Various reactive oxygen species(ROS)produced by the oxidation of pyrite played important roles in the transformation of environmental substances and the attenuation of pollutants.The present study systematically summarizes the reaction mechanisms and influencing factors on the ROS production through the pyrite oxidation,and geochemical effects of the ROS.Under the acidic and anoxic condition,the oxidation of adsorbed H_(2)O by surface Fe^(3+)at the sulfur defect is the main mechanism to produce•OH.Under the aerobic condition,the surface reaction of Fe(Ⅱ)with O_(2) produced H_(2)O_(2),which can produce•OH through the heterogeneous/homogeneous Fenton reaction.Under the light irradiation,as a semiconductor mineral,pyrite produces photogenerated holes and electrons,which further promoted the ROS generation.The activity of the ROS generated by the oxidation of pyrite is affected by the selective faces of pyrite crystal,the isomorphous substitutions in the structure of pyrite and the coexisting substances in the environment.The ROS produced by the oxidation of pyrite could be one of the driving forces for the oxidation event of the early Earth,played important influence on the increase of global land-sea sulfur flux and the formation of banded iron formations,and played greatly controlling effects on the migration and transformation of pollutants of heavy metals and organic matters in the environment.The following aspects,including the contributions of homogeneous and heterogeneous reactions and various ROS products on the oxidation reaction,the influences of species of substituted metal ions and their microscopic coordination environment on the ROS production through the oxidation of pyrite,and the microstructural variation of the surface of pyrite during the reaction.

关 键 词：黄铁矿 氧化反应 活性氧物种 晶面效应 类质同象置换 

分 类 号：P59[天文地球—地球化学] P574[天文地球—地质学]