Influence of a bio-based fertilizer on pharmaceuticals uptake by wheatgrass in soil

Establishing linear or nonlinear relationships for the uptake of both neutral and ionized pharmaceuticals by crops with key parameters is crucial for understanding the variations in uptake behavior among pharmaceuticals, yet it remains highly challenging. In this study, greenhouse experiments were conducted using wheatgrass (Triticum aestivum) grown in Finnish soil without (FS) and with a BBF (FO), spiked with seventeen neutral and ionized pharmaceuticals, to explore these relationships and investigate the impact of BBFs on their uptake. For the first time, a linear model revealed a significant correlation between BCF_spw (bioaccumulation concentration factors based on soil pore water) and both half-life and solid-water distribution coefficients (K_d) of studied pharmaceuticals in soil. The correlation varied between compounds with short half-lives (<14 days; R²=0.73) and those with long half-lives (>14 days; R²=0.70). The coefficient ratios of K_d to half-life in the model were 3.4 and 14.7 (g/ml)⋅day for compounds with long and short half-lives, respectively, suggesting a predominant influence of sorption of compounds on their bioaccumulation in wheatgrass compared to persistence. BBF significantly enhanced their sorption, thereby reducing pharmaceutical uptake by plants despite increased persistence. These findings suggest BBFs may be a promising tool to mitigate pharmaceutical accumulation in crops.