鲁西南沿黄地区浅部土壤氟元素富集规律

Enrichment regularity of fluorine in shallow soils along the Yellow River insouthwestern Shandong Province

黄河下游冲洪积平原是我国主要的土壤和地下水高氟区之一,“地氟病”给当地人民健康造成了一定的危害。为研究鲁西南沿黄地区浅部土壤中F元素的富集规律,采集该区表层及下部垂向土壤控制样品进行地球化学指标测定;运用统计学原理对研究区土壤粒径和地球化学指标测试结果进行分析,从土壤质地、化学指标、矿物风化程度与F含量的相关性角度分析鲁西南沿黄地区土壤中F元素的空间分布特征和富集规律。结果表明,研究区表层土壤中F含量的平均值为594 mg/kg,高于华北平原典型区及山东地区平均水平,约80%面积的土壤F含量过剩;浅部土壤中粉粒物质的质量分数平均值为72.99%,黏粒物质的质量分数平均值为20.31%,砂粒物质的质量分数平均值为6.70%。研究区土壤中的F元素平面上易在地势低平处富集,垂向上易在土壤表层富集。土壤中F的物源为黄土高原黄土,F含量受土壤中黏粒含量的控制,与之呈显著的正相关;土壤中F含量与Ca、Al、Fe、Mg、K、Ti、Mn、N、S、V、Zn、Cr含量及CEC(阳离子交换量)呈正相关,与Si、Na含量及pH值呈负相关;土壤中的F元素随土壤颗粒化学风化程度的增高呈富集趋势。

The alluvial plain in the lower reaches of the Yellow River where the study area is located is one of the main high-fluoride areas in soil and groundwater in China,and geofluorosis has caused certain harm to the health of local people.To study the enrichment regularity of fluorine in the shallow soil along the Yellow River in southwestern Shandong Province,the surface and lower vertical soil controlled-samples were collected for geochemical index testing and analysis.The results of soil particle size and geochemical indexes in the study area were analyzed by statistical principles,and the spatial distribution characteristics and enrichment law of fluorine in the soil along the Yellow River in southwestern Shandong Province were analyzed from the perspective of the correlation between soil texture,chemical indexes,mineral weathering degree and fluorine content.The results showed that the average content of fluorine in the surface soil of the study area was 594 mg/kg,which was higher than the average level of North China Plain and Shandong,and about 80%of the surface soil had excess fluorine content.The average mass fraction of silt,clay and sand in shallow soil is 72.99%,20.31%and 6.70%respectively.In the study area,the fluorine element is easy to accumulate in the low and flat terrain on the plane,and in the vertical soil surface.The source of fluorine in soil is from Loess Plateau,and its content is controlled by the clay content in soil,which has a significant positive correlation with fluorine.Soil fluorine content was positively correlated with Ca,Al,Fe,Mg,K,Ti,Mn,N,S,V,Zn,Cr content and CEC,and negatively correlated with Si,Na content and pH value.The concentration of fluorine element in soil increased with the increase of chemical weathering degree of soil particles.