在表土中,天然放射性核素的活性浓度(以下简称NRs)由于从肥料中添加NRs而增加,灌溉水,和空气粉尘污染。另一方面,各种物理化学和环境过程,如放射性衰变,挥发,浸出,侵蚀,和植物的吸收是表层土壤中NRs活性浓度降低的原因。在这项研究中,40K的行为,210Pb,226Ra,238U,通过CEMC土壤模型和HYDRUS-1D模型对表层土壤中的232Th进行了建模。提出了一个指数方程来估算这些放射性核素在表层土壤中的积累速率。评估了水菠菜的放射性核素的长期积累(IpomoeaAquaticaForssk。)土壤(以下称VES)和水稻(水稻)土壤(以下称RIS)。我们发现,目前的农业实践导致了水菠菜土壤中40K活性浓度的增加,40K,210Pb,226Ra,和232Th在水稻土壤中的活性浓度。放射性核素的积累速率顺序为238U<232Th<226Ra<210Pb<40K。种植25年的水菠菜可以增加/减少40K的(165±6)Bq,-210Pb的(8.2±0.7)Bq,-226Ra的(4.3±0.2)Bq,-238U的(70.3±0.3)Bq,1kg土壤中232Th的-(1.8±0.1)Bq。对于水稻种植,这些值为+(1004±39),+(3.3±0.2),+(3.0±0.2),-(5.1±0.3),(2.2±0.1)Bqkg-1for40K,210Pb,226Ra,238U,和232Th,分别。
In topsoils, the activity concentrations of natural radionuclides (hereafter NRs) increase due to the addition of NRs from fertilizers, irrigation water, and air dust pollution. On the other hand, various physical-chemical and environmental processes such as radioactive decay, volatilization, leaching, erosion, and plant uptake were responsible for the decrease of the activity concentrations of NRs in the topsoils. In this study, behaviours of 40K, 210Pb, 226Ra, 238U, and 232Th in topsoils were modelled by the CEMC soil model and the HYDRUS-1D model. An exponential equation was proposed for estimating the accumulation rates of these radionuclides in the topsoils. Long-term accumulation of radionuclides was assessed for water spinach (Ipomoea Aquatica Forssk.) soil (hereafter VES) and rice (Oryza sativa L.) soil (hereafter RIS). We found that the current agricultural practices caused the increase of 40K activity concentration in the water spinach soil, and 40K, 210Pb, 226Ra, and 232Th activity concentrations in the rice soil. The accumulation rates of radionuclides were in the order 238U < 232Th < 226Ra < 210Pb < 40K. 25 years of cultivation with water spinach can increase/decrease + (165 ± 6) Bq of 40K, - (8.2 ± 0.7) Bq of 210Pb, - (4.3 ± 0.2) Bq of 226Ra, - (7 0.3 ± 0.3) Bq of 238U, and - (1.8 ± 0.1) Bq of 232Th in 1 kg soil. For rice cultivation, these values are + (1004 ± 39), + (3.3 ± 0.2), + (3.0 ± 0.2), - (5.1 ± 0.3), (2.2 ± 0.1) Bq kg-1 for 40K, 210Pb, 226Ra, 238U, and 232Th, respectively.