A mathematical model for the behaviour of Se-79 in soils and plants that takes account of seasonal variations in soil hydrology

Abstract

Se-79 is a long-lived radionuclide of potential radiological significance in relation to the deep geological disposal of solid radioactive wastes. In the context of release to the terrestrial environment, its main radiological impact is delivered through food chain pathways. Therefore, its accumulation in soils and uptake by plants is an important consideration in post-closure safety assessment studies. However, representation of its behaviour in the soil-plant system requires consideration of the multiple valence states that it can exhibit under different redox conditions and its susceptibility to volatilisation. A simple model is described that includes seasonal variations in soil hydrology and their effects on the mobility and root uptake of Se-79. Illustrative calculations are undertaken with the model, to demonstrate its capabilities for interpreting experimental data on the behaviour of Se-79 in soils and plants, and for making projections on the long-term behaviour of Se-79 transported to soils.

Mathematical Model to Simulate the Transfer of Heavy Metals from Soil to Plant

“…Other variation curves of the concentrations of heavy metals, resulting from similar mathematical models, appear in study [68]; however, on a higher time scale. Also, study [50] presents predictions on the absorption of zinc in lettuce, zinc being the most absorbed metal.…”

Multi-criteria assessment to screen climate smart rice establishment techniques in coastal rice production system of India

“…Increased water productivity in AWD systems could be attributed to reduced seepage and percolation loss compared to flood irrigation. However, such losses are highly reliant on a soil’s hydrological characteristics ( Sharma et al., 2002 ; Pérez-Sánchez et al., 2012 ). Saving of water in AWD, SRI-AWD (20%–50%), and DSR (13%–60%) as compared to flooding was also reported by several workers ( Singh et al., 2013 ; Dass et al., 2016 ; Carrijo et al., 2017 ; Mboyerwa et al., 2021 ).…”

“…Sustainable rice cultivation in Asia is important for global food security, as rice fulfills the calorie requirement of more than 50% of the world population. As per the future projection, the rice production should be increased by 30% to meet out the future food demand (Pathak et al, 2020). Currently, rice is grown on 43.79 million hectares (Mha) of cultivated land in India, with a production of 116.4 million tons (Mt) (GOI, 2020).…”

Advanced spatio-temporal modelling in long-term radiological assessment models—radionuclides in the soil column

“…As well as being used to determine the transfer rates between the compartments, the CIEMAT model also uses θ to give volatilisation loss for selenium, using a similar approach to equation (2). Details are given in Pérez-Sánchez et al (2012).…”

“…Building upon experience in the context of acute releases to the biosphere (e.g. Walke et al 2012), there have been recent developments in biosphere PA modelling, including an increase in the spatial resolution with which the soil column is represented (Kłos et al 2011, Pérez-Sánchez et al 2012. Kłos et al (2011) were able to reproduce features seen in experimental measurements of iodine concentrations in a drained agricultural soil profile with a near-surface water table, using a ten-layer compartment model with saturation dependent k d s in each of the ten layers; illustrative modelled and measured profiles for iodine are reproduced in figure 1.…”