煤层及矸石山长期接触空气导致自发氧化的现象及隐燃和自燃现象统称为煤火，工业革命以来全球煤火不断但当代我国北方煤火当属世界之最。古今中外煤矿人视地表凝析物硫磺和芒硝(水合硫酸钠)为地下煤火标识；前期工作新察觉，煤火衍生硫酸而出现地表腐蚀土，煤火烟霾则异常富硫。本项目将以煤火硫的这些迹象为线索，深入现场取证，系统测定硫同位素，厘清煤中硫与诸形态硫的演化模式，揭示煤火硫的排放与环境归趋机制；系统运用ICP-MS等定量分析，验证煤火存在硫协同下的重金属排放；结合离子色谱分析等，区分煤火硫及重金属污染土、水和空气的环境效应。基本目标是阐明煤火硫与重金属的多元环境归趋，为煤火污染治理提供决策依据。同期，运用扫描电镜-单颗粒分析等表征凝析物和细颗粒物(芒硝、硫磺和烟霾PM2.5)，验证部分煤火硫排放物的远距离传输本领和潜在致霾作用，为深刻认识我国北方区域背景大气质量提供新思路。

Coal fire is a natural phenomenon that coal seam and gangue dump undergo spontaneous combustion after long-term air exposure and eventually experience open-fire combustion or underground smoldering. After Industrial Revolution, the anthropogenic activities have greatly intensified the coal fire worldwide, and today the northern China suffers from the most severe coal fire in the world. Before, it is generally acknowledged that the sulfur and sodium sulfate condensate on the ground surface of the coal fire area were regarded as markers of coal fire. Our previous work also observed surface corrosive soil caused by sulfuric acid derived from coal fire and abnormally enriched sulfur in the coal fire smoke. Therefore, this project, based on these known traits, field evidence, and lab analysis of sulfur isotopes, aims to rationalize the transformation mechanism of the sulfur and its multiple derivatives in coal, and further disclose the underlying mechanism of the release and environmental fate of the coal fire sulfur. This project also targets the synergistic release of heavy metal with sulfur from coal fire and their environmental effect on local soil, water body and atmosphere with help of chemical analysis instruments such as ICP-MS and ion chromatography. The multivariant environmental fate study of coal fire sulfur and heavy metal release would provide theoretical and policy-making evidence for coal fire pollution control. In addition, the study of the surface condensate (sulfur and sodium sulfate) and fine particle (PM2.5) of coal fire with single particle analysis method using SEM-EDX would examine the long-range transportation and haze-inducing potentials of coal fire sulfur, which might bring new thinking to the understanding of the ambient air quality of the northern China.