Modeling Bioavailability Limitations of Atrazine Degradation in Soils

Pesticide persistence in soils is a widespread environmental concern agro-ecosystems. One particularly persistent pesticide atrazine, which continues to be found and groundwater the EU despite having been banned since 2004. A range of physical biological barriers, such as sorption mass-transfer into bacterial cells, might limit atrazine degradation soils. These effects have observed experiments models working with simplified systems. We build on that work by developing biogeochemical model process. extended existing engineered system including refined representations processes across cell membrane well thermodynamic growth constraints. estimated parameters calibration data degradation, metabolite (hydroxyatrazine) formation, biomass, isotope fractionation from set controlled retentostat/chemostat experiments. then produced site-specific predictions for arable topsoil compared them field observations residual concentrations. overestimated long-term biodegradation soils, indicating this process likely not limited bioavailability or energetic constraints microbial growth. However, sorption-limited bioavailability, could explain fate main hydroxyatrazine. Future studies should seek alternative controls drive soil. This helps bridge gap between natural systems, allowing us use laboratory setups gain insight real