菏泽市主要河流中氟的分布及其影响因素

菏泽市地处鲁西南高氟地区,其河流中的高浓度氟化物不仅会通过径流过程影响南四湖水质,还会影响当地水生态平衡及人体健康。通过分析菏泽市主要河流中氟化物的时空分布特征,并结合地下水、土壤及废污水调查结果,探讨了影响河流中氟化物分布的主要因素。结果表明:研究区河流中氟化物的平均浓度在0.98~1.45 mg/L之间,氟化物浓度分布呈现出枯水期＞平水期＞丰水期、下游＞上游、支流＞干流的特征。氟化物浓度较高的河流呈现高pH、低钙的特点,水化学组分以Na-HCO₃型、Na-SO₄型为主。河流中氟化物的浓度主要受蒸发浓缩和岩石风化作用的影响。研究区地下水和土壤中氟化物的背景浓度整体较高。枯水期高氟地下水可能通过直接补给河流对河流水体产生影响,丰水期土壤中的氟也会通过径流过程汇入河流。人类工农业生产过程大量开采利用当地高氟地下水,而高氟废水最终则会进入河流,导致河流中氟化物的含量升高。

Study on the Distribution and Influencing Factors of Fluoride in Main Rivers of Heze City

In this study,the spatial and temporal distribution characteristics of fluoride in major rivers of Heze City were analyzed,and the main factors influencing the distribution of fluoride in rivers were discussed combined with the investigation results of groundwater,soil and wastewater discharge. The results show that the average fluoride concentration in rivers in the study area ranged from 0.98 mg/L to 1.45 mg/L. The distribution of fluoride concentration showed the characteristics of low flow period > normal flow period > high flow period,downstream > upstream,and tributary > main stream. Rivers with higher fluoride concentration were characterized by higher pH and lower calcium,with Na-HCO₃ and Na-SO₄ as the main hydrochemical components. The fluoride concentration in rivers was mainly influenced by evaporation and rock weathering. The background concentration of fluoride in groundwater and soil in the study area was generally high. In the dry season,the groundwater with high fluoride content might affect the river water body by directly supplying the river,and in the wet season,the fluoride in the soil would also flow into the river through the runoff process. Industrial and agricultural production exploited high-fluoride groundwater in large quantities,and the discharged wastewater contains a relatively high concentration of fluoride,resulting in the increase of fluoride content in rivers.