稳定性氢氧同位素研究土壤吸湿水的性质  

Study on the Hygroscopic Water Property of Soil by Stable Hydrogen and Oxygen Isotopes

作　　者：孙晓旭[1,2] 陈建生[1,3] 刘晓艳[1] 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098 [2]河海大学水利水电学院,江苏南京210098 [3]河海大学科学研究院,江苏南京210098

出　　处：《水电能源科学》2010年第3期118-120,共3页Water Resources and Power

基　　金：国家自然科学基金资助项目(50579017)

摘　　要：设计了室内试验模拟水的蒸发过程,在烘干的土壤样品中加入已知同位素组成的水样直至土壤水达到饱和,采用烘箱烘干使土壤含水率达到或小于吸湿含水率;通过抽真空降低水沸点与加热相结合的方法收集土壤吸湿水,测得其δ18O与δD值。结果表明:土壤吸湿层的水呈现明显的氢氧同位素富集,土壤水蒸发过程中吸湿层的水与其外层的薄膜水产生了同位素交换;吸湿层的水并非呈固态不能移动,在常温下可与其外层的水分子发生同位素交换。In this paper, indoor test is designed to simulate water evaporation process. The water having the known isotopic composition is added to the dried soil sample until the soil water is saturated, then the soil water is evaporated using the oven dry, finally the soil water moisture is equal or less than the hygroscopic water content. The hygroscopic water is collected by the vacuum pumping combined with the heating, then S180 and 8D of the collected water are determined. The results show that the hygroscopic water has an obvious enrichment of the hydrogen and oxygen isotopes and there are isotope exchange between the hygroscopic water and the film water. It is conclude that the hygroscopic water is not solid or irremovable, but the water molecule in the layer can have isotope exchange with others in the outer layers,

关 键 词：吸湿水 氢氧同位素 土壤 含水率 同位素交换 

分 类 号：P629[天文地球—地质矿产勘探]