模拟降雨条件下典型土壤汞淋溶风险研究

发布时间：2018-06-14 23:50

本文选题：汞 + 淋溶　；参考：《中国环境科学》2017年09期

【摘要】：采集全国22种典型土壤,通过室内土柱试验,探讨雨水(p H 5.6)作用下污染土壤Hg(外源添加2mg/kg)的淋溶和释放特征,并对影响土壤Hg淋溶特性的因子进行分析.结果表明,22种土壤Hg的释放过程大致分为3类,第1类包括黑土?黑钙土?草毡土?水稻土?暗棕壤?福州黄壤?黄泥土?栗钙土,这8种土壤在整个淋溶过程中淋出液Hg浓度极低,未超过地下水III级标准(1μg/L).第2类包括广西红壤?贵州黄壤?棕壤?灰钙土?黄绵土等5种土壤,淋溶前期(2~3L)Hg含量较低,到淋溶中期含量显著上升,随后出现下降,到淋溶末期(5~6L)淋溶液Hg含量降低到III级标准以下.第3类土壤包括砖红壤?黄棕壤?紫色土?褐土?赤红壤?潮土?盐碱土?江西红壤?棕漠土等9种土壤,淋溶过程呈现2个阶段,当淋溶体积在4L之内,淋出液中Hg浓度较高,且变化比较剧烈,对环境及地下水威胁较大,超出4L后,Hg释放速率明显变缓,浓度降低到III级标准以下.模拟降雨条件下22种土壤Hg的释放率为0.33%~5.95%,最高的是贵州黄壤,最低是吉林黑土,平均为1.55%.逐步回归分析的结果表明,土壤有机质(OM)?p H及土壤汞含量(THg)对降雨作用下土壤Hg累计释放量(q)有重要作用,三者累计的决定系数为0.5865,回归方程为lnq=1.8+0.62ln THg-0.109p H-0.918ln OM
[Abstract]:22 typical soils in China were collected. The leaching and release characteristics of Hg (2 mg / kg) in polluted soil under the action of Rain Water pH5.6 were studied, and the factors affecting the leaching characteristics of soil Hg were analyzed. The results show that the release process of Hg from 22 soils can be divided into three categories, the first type includes black soil? Calcareous soil? Grass felts? Paddy soil? Dark brown earth? Fuzhou yellow soil? Yellow clay? In chestnut soil, the concentration of Hg in leaching solution of these eight soils is very low during the whole leaching process, and does not exceed 1 渭 g / L ~ 1 渭 g / L ~ (-1) of groundwater grade III standard. Type 2 includes red soil in Guangxi? Guizhou yellow soil? Brown soil? Ash? The content of Hg in 5 kinds of soils, such as yellow spongy soil, was lower in the early stage of leaching, increased significantly in the middle stage of leaching, then decreased, and then decreased to the level of grade III in the late stage of leaching. The third type of soil includes latosol? Yellow brown earth? Purple soil? Cinnamon? Red earth? Wet soil? Saline soil? Red soil in Jiangxi? The leaching process of 9 kinds of soils, such as brown desert soil, showed two stages. When the leaching volume was within 4L, the concentration of Hg in leaching solution was higher, and the change was more intense, which threatened the environment and groundwater greatly, and the release rate of Hg decreased obviously when the leaching volume exceeded 4L. The concentration is reduced below the level III standard. Under simulated rainfall, the release rate of Hg in 22 soils was 0.33 and 5.95, the highest in Guizhou yellow soil and the lowest in Jilin black soil with an average of 1.55. The results of stepwise regression analysis showed that the soil organic matter (OMG) and soil mercury content (THG) played an important role in soil Hg release under rainfall. The cumulative determinant coefficient of the three factors was 0.5865, and the regression equation was lnq=1.8 0.62ln THg-0.109pH-0.918lnOM.
【作者单位】：农业部农业生态与资源保护总站;农业部环境保护科研监测所;
【基金】：国家自然科学基金资助项目(41203084,41371463) 国家水体污染控制与治理科技重大专项(2015zx07103-007) 国家重点研发计划(2016YFD0201306)
【分类号】：X53

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