甘肃河西走廊地区水中氟的分布规律及环境特征

The distributing regular of fluorine and its environmental characteristics in arid area of Hexi Corridor, Gansu Province

在甘肃河西走廊地区,随内陆流域水系的产生,径流消亡,从山区至山前平原,氟(F-)的迁移分布具有显著的淋溶-径流、径流-蒸发与溶滤-蒸发浓缩富集3个水文化学分带;在湖盆洼地以及沙漠边缘地区,不仅地下水中F-相对富集,且具有深部地下水F-含量大于浅层地下水及地表水F-含量的上小下大的垂直分带性;F-的富集与贫化与水化学特征关系密切,一般在低SO42-的贫钙碱性水环境,如Cl-·HCO3--Na+或HCO3--Na+型水中,有利于F-的溶解与富集。相对封闭的水文环境与干旱的气候条件为F-在水中溶解、迁移和富集提供了有利条件。

In arid area of Hexi Corridor, the NaF and KF are extensively distributed in the natural water, such as rivers, lakes and groundwater. From mountains to silt plain along with the formation, runoff and disappear of inland rivers, the distributing regular of F-can be markedly divided into three hydro-chemical zones: drench and dissolution-runoff zone, runoff-evaporation zone, dissolution-evaporation zone. There is a close relationship between high F- and the hydro-chemical characteristics. Generally, in the alkali water with lower contains of SO42- such as Cl-·HCO3--Na+ or HCO3--Na+ types, the F- can be easily dissolved and rich in water. The arid climatic conditions, rich source of fluorine and relatively close hydrological environment provide the advantage of F- to dissolution, transformation and rich in some regions.