【摘要】：探索同一空間下土壤-地下水-農(nóng)作物中Se(Selenium)的分布規(guī)律和不同介質(zhì)間Se的富集規(guī)律,以期為科學(xué)認(rèn)識(shí)同環(huán)境中不同元素和指標(biāo)對Se的分布及富集的影響作用提供理論依據(jù)。通過在富Se地區(qū)采集0~20 cm表層土壤樣品、0~11 m深層土壤剖面樣品、淺層灌溉用地下水樣品以及主要農(nóng)作物水稻和玉米籽實(shí),采用統(tǒng)計(jì)分析方法分析了研究區(qū)不同介質(zhì)中Se的分布規(guī)律、富集規(guī)律及影響因素。結(jié)果表明,研究區(qū)表層土壤中Se質(zhì)量分?jǐn)?shù)均值為0.311 mg?kg~(-1),直方圖表明其在0.10~0.25 mg?kg~(-1)和0.40~0.50 mg?kg~(-1)處有2個(gè)明顯峰值;相關(guān)分析表明表層土中Se質(zhì)量分?jǐn)?shù)與Al2O3和Cr呈負(fù)相關(guān),與P、Hg和Mn呈正相關(guān)(P0.001);Se在土壤剖面深度為0~100 cm以及7~11 m兩個(gè)層位上富集,在0~100 cm富集作用更顯著;不同深度土壤中Se主要賦存形態(tài)為強(qiáng)有機(jī)態(tài)、腐殖酸結(jié)合態(tài)和殘?jiān)鼞B(tài),三者最大可占總量的87.3%,且隨著深度下降而迅速下降;研究區(qū)淺層地下水中Se質(zhì)量濃度均值為0.337×10-3 mg?L~(-1),主要以Se(Ⅵ)存在,占總Se的95%,主要原因是Se(Ⅵ)溶解性、遷移性強(qiáng)且不易被吸附;水稻籽實(shí)Se與表層土Se質(zhì)量分?jǐn)?shù)相關(guān)性顯著(r=0.646,P=0.002),玉米籽實(shí)與表層土Se質(zhì)量分?jǐn)?shù)無顯著相關(guān)性(r=0.124,P=0.593);研究區(qū)富Se地塊的水稻籽實(shí)富Se率為43%,土壤Se質(zhì)量分?jǐn)?shù)等級由邊緣(0.125~0.175 mg?kg~(-1))至豐富(0.40 mg?kg~(-1)),水稻籽實(shí)Se的質(zhì)量分?jǐn)?shù)增量是玉米籽實(shí)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，

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