Dissolution and toxicity of silver nanoparticles in the presence of aquatic humic substances and extracellular polymeric substances

Abstract

Silver nanoparticles (NPs) with different coatings have been widely used in various applications such as medicines, textile industry, treatment of contaminants, etc. As NPs reach the levels, they can influence the quality and resistance of the molecules, and by means of biomagnification and the food chain they become humans. There are only few studies available in the literature about transformations that NPs may suffer in the aquatic environment, especially in the presence of aquatic organic substances, such as aquatic humic substances (AHS) and extracellular polymeric substances (EPS). Thus, the present project intent to evaluate the solubility, transformations and toxicity of silver NPs (Ag-NPs) in the presence of AHS and EPS. Pyrolysis coupled with gas chromatography mass spectrometer (PY-CG-MS), potentiometric titration, ultrafiltration/ inductively coupled plasma optical emission spectrometry and electrophoretic mobility. The toxicity will be assessed through ecotoxicological tests using a R. subcapitata microalgae as an organic test. Thus, this project aims to bring greater understanding about the reactivity and toxicity of nanoparticles and natural organic matter in aquatic systems. (AU)