银川平原松散沉积物中氟的浸泡释放试验

Soaking experiment on fluoride release from loose rocks in Yinchuan plain

为了查明银川平原浅层地下水中氟的来源,采用浸泡释放试验对平原松散沉积物中氟的释放过程进行了研究,结果表明:在碱性还原环境中有利于氟的释放,释放量的大小与岩性及同释放的其它离子成分密切相关。总体而言,第三系地层中氟的释放量大于第四系地层,其中红色粉砂岩的释放量、释放速率最大;在释放过程中,与同时释放的钠、硫酸根离子呈正相关,与钙、镁离子呈负相关,当电导率<500μs/cm时,各离子对氟的释放影响不明显,当>500μs/cm时,则随释放的优势离子而发生变化。

To find out the provenance of high-fluorine groundwater in Yinchuan plain, the authors designed the soaking experiment on fluorid releasing from loose rocks. The results show that it is conducive to the release of fluoride in the reduction and alkaline environment, and the release quantity are closely related to the lithology and the other ions. Overall, the fluoride release quantity in the Tertiary strata is greater than the Quaternary strata, especially, the red sandstone from the Tertiary strata have the maxi- mum release quantity and release rate ; in the release process, the release quantity of fluorine was positively correlated with the simultaneous release of sodium sulfate and negatively correlated with calcium and magnesium ions, and the conductivity can also affect the release of fluorine.