Nanoplastic/metal interaction under flow conditions: an innovative coupling of microfluidic and spectrometry.

While nanoplastic (NPs) migration is contingent upon water flow and transport processes at the macro-scale, it is widely acknowledged that molecular, nano, and microscale processes exert significant influence on nanoparticle fate in the environment. Due to their colloidal properties and charged surfaces, NPs can also influence trace metal speciation and transport in natural matrices. Once plastic degradation is initiated under environmental conditions, oxygenated functions such as carboxylic groups begin forming on their surface1. This is combined with the release of functionalized NPs capable of transporting metals. This leaves the NPs/metal interaction at the root of the ecotoxicological risk assessment process. Most of studies carried out explore this interaction at a static macroscopic level using batch experiments. This is explained by the lack of methodologies and the limited accessibility to the pore scale mechanisms that govern the NPs/metal interaction especially under flow conditions. This interaction has historically been described and understood at the macroscopic level, yet her core is rooted at the pore scale. To bridge this gap, we developed real-time monitoring of NPs/metal interactions combining microfluidics to QQQ-ICP-MS in single particle mode. We studied the interaction between functionalized polystyrene latex (PSLs) and Cerium (Ce) both under static conditions - in batch experiments and under flow conditions - microfluidic. This investigation aims to delve into the adsorption mechanisms between PSLs and Ce and to explore the adsorption theory at a pore scale level. Experiments revealed significant Ce adsorption onto PSLs under flow, with a remarkably high adsorption efficiency of 99 Also see: https://micro2024.sciencesconf.org/559429/document