三江平原富Se地区地下水-土壤-农作物中Se富集规律及影响因素
发布时间：2018-12-14 17:54
【摘要】：探索同一空间下土壤-地下水-农作物中Se(Selenium)的分布规律和不同介质间Se的富集规律,以期为科学认识同环境中不同元素和指标对Se的分布及富集的影响作用提供理论依据。通过在富Se地区采集0~20 cm表层土壤样品、0~11 m深层土壤剖面样品、浅层灌溉用地下水样品以及主要农作物水稻和玉米籽实,采用统计分析方法分析了研究区不同介质中Se的分布规律、富集规律及影响因素。结果表明,研究区表层土壤中Se质量分数均值为0.311 mg?kg~(-1),直方图表明其在0.10~0.25 mg?kg~(-1)和0.40~0.50 mg?kg~(-1)处有2个明显峰值;相关分析表明表层土中Se质量分数与Al2O3和Cr呈负相关,与P、Hg和Mn呈正相关(P0.001);Se在土壤剖面深度为0~100 cm以及7~11 m两个层位上富集,在0~100 cm富集作用更显著;不同深度土壤中Se主要赋存形态为强有机态、腐殖酸结合态和残渣态,三者最大可占总量的87.3%,且随着深度下降而迅速下降;研究区浅层地下水中Se质量浓度均值为0.337×10-3 mg?L~(-1),主要以Se(Ⅵ)存在,占总Se的95%,主要原因是Se(Ⅵ)溶解性、迁移性强且不易被吸附;水稻籽实Se与表层土Se质量分数相关性显著(r=0.646,P=0.002),玉米籽实与表层土Se质量分数无显著相关性(r=0.124,P=0.593);研究区富Se地块的水稻籽实富Se率为43%,土壤Se质量分数等级由边缘(0.125~0.175 mg?kg~(-1))至丰富(0.40 mg?kg~(-1)),水稻籽实Se的质量分数增量是玉米籽实的1.30倍。
[Abstract]:The distribution of Se (Selenium) in soil-groundwater crops and the enrichment of Se in different media were explored in the same space. In order to provide a theoretical basis for the scientific understanding of the effects of different elements and indicators on the distribution and enrichment of Se in the same environment. The surface soil samples of 0 ~ 20 cm, soil profile of 0 ~ 11 m deep layer, groundwater samples for shallow irrigation, rice and corn seeds of main crops were collected in Se rich area. The distribution, enrichment and influencing factors of Se in different media in the study area were analyzed by statistical analysis method. The results showed that the average mass fraction of Se in the surface soil was 0.311 mg?kg~ (-1), and the histogram showed that there were two obvious peaks at 0.100.25 mg?kg~ (-1) and 0.400.50 mg?kg~ (-1). Correlation analysis showed that Se content in surface soil was negatively correlated with Al2O3 and Cr, and positively correlated with Al2O3 and Mn (P0.001); Se was enriched at the depth of 0 ~ 100 cm and 7 ~ 11 m in soil profile, especially in 0 ~ 100 cm). The main forms of Se in soil at different depths were strong organic form, humic acid bound state and residue state, which accounted for 87.3% of the total amount, and decreased rapidly with the decrease of depth. The average mass concentration of Se in shallow groundwater is 0.337 脳 10 ~ (-3) mg?L~ (-1), which mainly exists as Se (鈪，
本文编号：2379060
[Abstract]:The distribution of Se (Selenium) in soil-groundwater crops and the enrichment of Se in different media were explored in the same space. In order to provide a theoretical basis for the scientific understanding of the effects of different elements and indicators on the distribution and enrichment of Se in the same environment. The surface soil samples of 0 ~ 20 cm, soil profile of 0 ~ 11 m deep layer, groundwater samples for shallow irrigation, rice and corn seeds of main crops were collected in Se rich area. The distribution, enrichment and influencing factors of Se in different media in the study area were analyzed by statistical analysis method. The results showed that the average mass fraction of Se in the surface soil was 0.311 mg?kg~ (-1), and the histogram showed that there were two obvious peaks at 0.100.25 mg?kg~ (-1) and 0.400.50 mg?kg~ (-1). Correlation analysis showed that Se content in surface soil was negatively correlated with Al2O3 and Cr, and positively correlated with Al2O3 and Mn (P0.001); Se was enriched at the depth of 0 ~ 100 cm and 7 ~ 11 m in soil profile, especially in 0 ~ 100 cm). The main forms of Se in soil at different depths were strong organic form, humic acid bound state and residue state, which accounted for 87.3% of the total amount, and decreased rapidly with the decrease of depth. The average mass concentration of Se in shallow groundwater is 0.337 脳 10 ~ (-3) mg?L~ (-1), which mainly exists as Se (鈪，
本文编号：2379060
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