摘要
地下水中氟含量过高是造成地氟病的重要原因。通过对地下水中氟的含量和水化学特征分析发现:天津滨海地区深层地下水中氟的含量在0.98～5.51 mg/L之间,平均高达2.78 mg/L,绝大部分水体中氟的含量都超过了国家规定安全饮用标准。氟在地下水中呈现出随着深度的增加逐渐降低的趋势:枯水期第Ⅱ、Ⅲ组含水组地下水中氟的含量明显高于第Ⅳ、Ⅴ含水组地下水;丰水期第Ⅱ含水组高于其下部的含水组。氟的含量在枯水期高于丰水期。造成上述分布特征主要是由以下因素造成的:北部山区含氟较高的花岗岩分布广泛及历史上发生的多次海侵活动为滨海地区高氟地下水提供了丰富的物源;滨海地区平原地带及富含钙核的海相沉积环境为氟离子在此处富集提供了条件。较高的pH值和HCO3-在水岩相互作用中对氟离子的溶解富集有明显的促进作用,这种溶解作用在枯水期表现得更明显。
High fluorine concentration in groundwater is an important cause of endemic fluorosis. After analyzing fluorine concentration and hydrochemistry characteristics in the groundwater, it was found that fluoride concentration of deep groundwater in Tianjin coastal area was between 0.98-5.51 mg/L, with average 2.78mg/L, most of which has exceeded national safe drinking water standard. Fluorine concentration in deep groundwater showed a trend to decrease with increasing depth. In the dry season, fluorine concentration in aquifer groups Ⅱ , Ⅲ was significantly higher than group Ⅲ, Ⅴ In the wet season, the group lI showed higher values than the deeper aquifers. Fluorine content in the dry season was higher than that in the wet period. Wide distributions of fluorinated granites in northern mountains and repeated transgression activities in history had made rich fluoride sources, which mainly contribute to the generating of high fluorine groundwater in the coastal area. Fluorine anions are easy to be concentrated in coastal plains and rich calcareous concretions marine depositional environment. In addition, high pH and HCO3- level play significant roles in facilitating the dissolution and enrichment of fluorine anions in water-rock interaction, and the dissolution function would be more obvious during dry season.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2013年第9期45-50,共6页
Environmental Science & Technology
基金
国家自然科学基金(40803002
41172315)
关键词
深层地下水
氟
分布规律
影响因素
deep groundwater
fluorine
distribution characteristics
influencing factor
