Dissolution of Ag Nanoparticles in Agricultural Soils and Effects on Soil Exoenzyme Activities

To assess environmental risks related to the mobility and toxicity of AgNPs, chemical availability AgNPs polyvinylpyrrolidone-coated (PVP-AgNPs) in three agricultural soils was quantified a pot experiment. Porewater collection soil extractions with 0.01 M CaCl2, 0.4 Glycine (pH 1.5) 0.05 NH4-EDTA were performed. The effect on exoenzyme activities also assessed. concentration low (<0.4% <0.04% dosed Ag, for PVP-AgNPs, respectively) only detected acidic 4.4 4.9). PVP-coating reduced downward possibly their dissolution rate (and subsequent release dissolved Ag+ ions into porewater). variation organic matter enzymatic activity larger than that as no significant additional inhibitory from Ag could be observed. Only at pH presence complexing ligands form very stable complexes (0.4 extraction up 58% added released (independently PVP coating). An glycine is proposed useful indicator potentially available soils.