[Simulation of the Absorption, Migration and Accumulation Process of Heavy Metal Elements in Soil-crop System]

Soil-crop system is an important way that heavy metals harm the ecological environment and human health. To research and understand the process of heavy metal absorption, migration and accumulation in soil-crop system is important for the prevention and control of heavy metal pollution and the health of human beings. In this paper, we established a model for crop uptake of heavy metals to calculate the heavy metals contents of wheat roots, stems, leaves and grains, and we analyzed the accumulation process of heavy metals in roots, stems, leaves and grains in the growth cycle of wheat. The predicted values were compared with the measured values to test the accuracy of the model. The results demonstrated that different parts of wheat had different heavy metal absorption capacity, the absorption of the roots was the strongest, followed by leaves, and the absorption capacity of stems and grains was weak. In addition, the contents of different heavy metals in each part of wheat were also significantly different. The content of Cu was the highest, followed by Ni, while the contents of Pb and Cd were small. In the process of wheat growth, the heavy metal accumulation rate of stem, leaf and grain began to slow down at 90, 60 and 100 days respectively, and the concentration of heavy metals reached the maximum gradually, while the accumulation rate of heavy metals in roots showed a growing trend. We studied the process of absorption, migration and accumulation of heavy metals in soil-crop system by using numerical simulation technology, which can provide scientific basis for preventing the ecological and health risks of heavy metal pollution.