Gommers A, Gäfvert T, Smolders E, Merckx R, Vandenhove H
Radiation Protection Research Department, Radioecology Section, SCK CEN, Boeretang 200, 2400 Mol, Belgium.
J Environ Radioact. 2005;78(3):267-87. doi: 10.1016/j.jenvrad.2004.05.007.
The feasibility of willow short rotation coppice (SRC) for energy production as a revaluation tool for severely radiocaesium-contaminated land was studied. The effects of crop age, clone and soil type on the radiocaesium levels in the wood were assessed following sampling in 14 existing willow SRC fields, planted on radiocaesium-contaminated land in Sweden following Chernobyl deposition. There was only one plot where willow stands of different maturity (R6S2 and R5S4: R, root age and S, shoot age) and clone (Rapp and L78183 both of age category R5S4) were sampled and no significant differences were found. The soils differed among others in clay fraction (3-34%), radiocaesium interception potential (515-6884 meq kg(-1)), soil solution K (0.09-0.95 mM), exchangeable K (0.58-5.77 meq kg(-1)) and cation exchange capacity (31-250 meq kg(-1)). The soil-to-wood transfer factor (TF) of radiocaesium differed significantly between soil types. The TF recorded was generally small (0.00086-0.016 kg kg(-1)), except for willows established on sandy soil (0.19-0.46 kg kg(-1)). Apart from the weak yet significant exponential correlation between the Cs-TF and the solid/liquid distribution coefficient (R2 = 0.54) or the radiocaesium interception potential, RIP (R2 = 0.66), no single significant correlations between soil characteristics and TF were found. The wood-soil solution 137Cs concentration factor (CF) was significantly related to the potassium concentration in the soil solution. A different relation was, however, found between the sandy Trödje soils (CF = 1078.8 x m(K)(-1.83), R2 = 0.99) and the other soils (CF = 35.75 x m(K)(-0.61), R2 =0.61). Differences in the ageing rate of radiocaesium in the soil (hypothesised fraction of bioavailable caesium subjected to fast ageing for Trödje soils only 1% compared to other soils), exchangeable soil K (0.8-1.8 meq kg(-1) for Trödje soils and 1.5-5.8 meq kg(-1) for the other soils) and the ammonium concentration in the soil solution (0.09-0.31 mM NH4+ for the Trödje soils compared to 0.003-0.11 mM NH4+ for the other soils) are put forward as potential factors explaining the higher CF and TF observed for the Trödje soils. Though from the dataset available it was not possible to unequivocally predict the Cs-soil-to-wood-transfer, the generally low TFs observed point to the particular suitability for establishment of SRC on radiocaesium-contaminated land.
研究了柳树短轮伐期矮林（SRC）作为重度放射性铯污染土地的一种修复工具用于能源生产的可行性。在瑞典切尔诺贝利事故沉降后受放射性铯污染土地上种植的14个现有柳树SRC林地进行采样后，评估了作物年龄、无性系和土壤类型对木材中放射性铯水平的影响。只有一个样地对不同成熟度（R6S2和R5S4：R为根龄，S为枝龄）和无性系（年龄类别均为R5S4的Rapp和L78183）的柳树林分进行了采样，未发现显著差异。土壤在粘粒含量（3 - 34%）、放射性铯截留潜力（515 - 6884 meq kg⁻¹）、土壤溶液钾（0.09 - 0.95 mM）、交换性钾（0.58 - 5.77 meq kg⁻¹）和阳离子交换容量（31 - 250 meq kg⁻¹）等方面存在差异。放射性铯的土壤 - 木材转移因子（TF）在不同土壤类型之间存在显著差异。记录的TF一般较小（0.00086 - 0.016 kg kg⁻¹），但在砂土上种植的柳树除外（0.19 - 0.46 kg kg⁻¹）。除了铯 - TF与固/液分配系数（R² = 0.54）或放射性铯截留潜力RIP（R² = 0.66）之间存在微弱但显著的指数相关性外，未发现土壤特性与TF之间有单一显著相关性。木材 - 土壤溶液¹³⁷Cs浓度因子（CF）与土壤溶液中的钾浓度显著相关。然而，在砂土Trödje土壤（CF = 1078.8 × m(K)⁻¹.⁸³，R² = 0.99）和其他土壤（CF = 35.75 × m(K)⁻⁰.⁶¹，R² = 0.61）之间发现了不同的关系。提出土壤中放射性铯老化速率的差异（假设生物可利用铯的快速老化部分，Trödje土壤仅为1%，而其他土壤为其他值）、交换性土壤钾（Trödje土壤为0.8 - 1.8 meq kg⁻¹，其他土壤为1.5 - 5.8 meq kg⁻¹）和土壤溶液中的铵浓度（Trödje土壤为0.09 - 0.31 mM NH₄⁺，其他土壤为0.003 - 0.11 mM NH₄⁺）是解释在Trödje土壤中观察到较高CF和TF的潜在因素。尽管根据现有数据集无法明确预测铯从土壤到木材的转移，但观察到的一般较低的TF表明在放射性铯污染土地上特别适合建立SRC。
