Modeling the Translocation and Transformation of Chemicals in the Soil‐Plant Continuum: A Dynamic Plant Uptake Module for the HYDRUS Model

Abstract

Food contamination is responsible for thousands of deaths worldwide every year. Plants represent the most common pathway for chemicals into the human and animal food chain. Although existing dynamic plant uptake models for chemicals are crucial for the development of reliable mitigation strategies for food pollution, they nevertheless simplify the description of physicochemical processes in soil and plants, mass transfer processes between soil and plants and in plants, and transformation in plants. To fill this scientific gap, we couple a widely used hydrological model (HYDRUS) with a multicompartment dynamic plant uptake model, which accounts for differentiated multiple metabolization pathways in plant's tissues. The developed model is validated first theoretically and then experimentally against measured data from an experiment on the translocation and transformation of carbamazepine in three vegetables. The analysis is further enriched by performing a global sensitivity analysis on the soil-plant model to identify factors driving the compound's accumulation in plants' shoots, as well as to elucidate the role and the importance of soil hydraulic properties on the plant uptake process. Results of the multilevel numerical analysis emphasize the model's flexibility and demonstrate its ability to accurately reproduce physicochemical processes involved in the dynamic plant uptake of chemicals from contaminated soils.

On the Use of Mechanistic Soil–Plant Uptake Models: A Comprehensive Experimental and Numerical Analysis on the Translocation of Carbamazepine in Green Pea Plants

“…In particular, smaller values of α and n calculated for the first soil layer are compatible with an increased pore heterogeneity caused by a higher root density in that part of the soil column. 56 The estimated soil–water partition coefficient, K f CBZ , is in line with the results of the batch experiment (i.e., K f CBZ ≈ 2.8 cm 3β μg 1-β g –1 ) and with other studies, 27 , 34 thus confirming the overall reliability of the analysis. The narrow confidence intervals estimated for the soil hydraulic parameters suggest that the soil behavior influences the uptake and translocation processes.…”

“…The numerical model developed by Brunetti et al 27 is used to simulate the translocation and transformation of CBZ in the soil–plant continuum. The model combines the widely used hydrological model, HYDRUS-1D, 28 with a multicompartment model of dynamic plant uptake.…”

“…The model combines the widely used hydrological model, HYDRUS-1D, 28 with a multicompartment model of dynamic plant uptake. 38 For a thorough description of the model, please refer to ref ( 27 ).…”

“…Numerical models play an important role in better understanding of physicochemical processes involved in the dynamic uptake of chemicals and risk assessment. To predict the behavior of non-ionic organic compounds in the soil–plant continuum, Brunetti et al 27 coupled the widely used Richards-based solver, HYDRUS-1D, 28 with a modified version of the multicompartment dynamic plant uptake model developed by Trapp. 29 The fully coupled soil–plant model is able to provide a comprehensive mechanistic description of transport and reaction processes in the soil–plant continuum.…”

How microbial community composition, sorption and simultaneous application of six pharmaceuticals affect their dissipation in soils

“…Further propagation of pharmaceuticals in the environment depends on their sorption and dissipation in the vadose zone (e.g., Carter et al, 2019;Kümmerer, 2009aKümmerer, , 2009bZhi et al, 2019). The knowledge of the properties characterizing sorption and dissipation of various pharmaceuticals in this environment is crucial, for example, when using models simulating transport of these compounds in soils and their uptake by plants (e.g., Brunetti et al, 2019).…”