Mobilization of cesium in organic rich soils: Correlation with production of dissolved organic carbon
Mobilization of cesium in organic rich soils: Correlation with production of dissolved organic carbon
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富含有机物的土壤中铯的动员：与溶解有机碳的产生的相关性
DOI：
10.1007/bf00157418
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
H. Dörr
中科院分区：
文献类型：
--
作者：
I. Tegen;H. Dörr
本文研究了未扰动森林土壤中137cs的向下运动。测定了渗水中137cs活性的季节变化和深度剖面，渗水中137cs是土壤中人为物质向下运动的运输介质。此外，还研究了137cs的调动与溶解有机碳（DOC）生成的相关性。观察了5 cm深度渗流水中137cs和DOC通量的季节变化，其中夏季月份的最大通量比冬季月份的最小通量高一个数量级。137Cs通量与DOC通量相关，相关系数r= 0.63，且与土壤温度高度相关。这表明铯与土壤有机质结合。DOC的产生受土壤有机质的微生物分解控制，我们认为137cs的释放也是如此。137cs的实际输送速度（0.2±0.14 mm/a）（由渗流水中137cs浓度与土壤总137cs含量的加权平均值计算）比过去25年的平均输送速度（1.2±0.3 mm/a）（由137cs深度剖面计算）约小一个数量级。在未受扰动的土壤中，137cs的输运速度可能随着时间的推移而降低，因为它与比新鲜有机物更不易分解的陈年有机物结合。
A study of the downward movement of137Cs in an undisturbed forest soil is presented. Seasonal variations and depth profiles of137Cs activities were measured in seepage water, which is the transport medium for the downward movement of anthropogenic substances in soils. Furthermore the correlation of137Cs mobilization and production of dissolved organic carbon (DOC) was investigated. Seasonal variations of both137Cs and DOC fluxes in the seepage water in a depth of 5 cm depth were observed, where the maximum fluxes in the summer months were about one order of magnitude higher than the minimum fluxes in the winter months.137Cs fluxes are found to be correlated with DOC fluxes with a correlation coefficient ofr= 0.63, and both are highly correlated with soil temperature. This indicates that cesium is bound to soil organic material. The production of DOC is controlled by microbial decomposition of soil organic matter and we assume that this holds true for the137Cs release as well. The actual transport velocity (0.2 ± 0.14 mm/a) of137Cs (calculated by the weighed mean of137Cs concentration in the seepage water and the total137Cs content of the soil) is about one order of magnitude less than the mean transport velocity (1.2 ± 0.3 mm/a) over the past 25 years (calculated from the137Cs depth profile). It is possible that the transport velocity of137Cs in undisturbed soils decreases with time as it binds to aged organic material which is less easily decomposable than fresh organic material.