天然气中汞含量的变化规律及应用——兼述岩石和土壤中汞的含量

THE VARIATION AND APPLICATION OF MERCURY CONTENT FOR NATURAL GASES——ALSO STATE THE MERCURY CONTENT IN ROCKS AND SOILS

1953年日本熊本县水俣湾发生了历史上首次重金属——汞污染重大事件,国际上立即对汞污染问题给予了高度重视,此后相关领域关于汞研究的成果也不断涌现。文中介绍了天然气中汞含量的变化和气类型判识的应用,并概述了岩石和土壤汞的含量变化;由于汞的高电离势和高挥发性,汞极易形成化合物,也易于从化合物中再还原出来,所以汞在不同物质中含量不一样,甚至在同类物质中的含量也会有明显差别,例如汞在天然气中含量为2.8～3000000ng/m3,在陨石中的含量为0.004～38.94μg/g,在变质岩中含量为2～3900ng/g之间,在火成岩中含量为4.5～1600000ng/g之间,在沉积岩中含量为0.005～2000μg/g之间,在土壤中含量为1～290ng/g之间。还指出汞在沉积、迁移和聚集的过程中形态变化十分复杂,因此物质中汞含量的变化规律也会因为汞的地球化学特性、深大断裂、岩浆活动、岩性及地貌等因素的变化而改变;随着人们环保意识日益增强,技术手段改进、仪器精度提高和汞研究领域不断拓宽,对汞含量在天然气中的变化规律的认识也会更加客观。

The pollution of mercury happened at Minamata Bay, Kumamoto town, Japan in 1953 was the first heavy metal pollution event in our history. Since then more attentions have been attracted on mercury pollution and new research findings about it have being emerged in related fields. This paper introduces the variation of mercury content among natural gases, rocks and soils, also states the application of mercury as an index for natural gas identification. The mercury is characterized by high ionic potential and high volatility, which result in easy conversion between the atoms and components of the element. Thus, the mercury content varied obviously not only in different matters but even in the same sort of masses. For instance, the mercury content varied from 2.8 to 3 000 000 ng/m^3 in natural gases, 0. 004 to 38.94μg/g in meteoric rocks, 2 to 3 900 ng/g in metamorphic rocks, 4. 5 to 1 600 000 ng/g in igneous rocks, 0. 005 to 2 000μg/g in sedimentary rocks, and 1 to 290 ng/g in soils respectively. The changes of mercury species are complex during the process of subsiding, migration and accumulation. Furthermore, mercury content can be changed by! its geo-chemical characteristics, deep giant faults, activities of magma, litho and topographer. The variation of mercury content in natural gas can be studied more objectively in the future through enhanced awareness of environmental protection, improved technology methods, elevated instrument accuracy and enlarged research province of mercury.