Towards a better understanding of nanoparticles transport in porous media
A thorough understanding of the mechanisms responsible for transport of contaminants, such as engineered nanoparticles (ENPs) and nano-plastics, in porous media is important for risk assessment and for prediction of the efficiency of terrestrial nano-technologies such as nano-fertilizers and remediation of contaminated sites with zero valent iron ENPs. Unfortunately, there are no many studies that independently and systematically assess the influence of different porous media characteristics and different physicochemical processes on the transport and retention of the nano-objects. In this context, a novel off-lattice three-dimensional (3D) coarse-grained Monte Carlo model is developed to study ENPs behavior in porous media. This model is based on individual particle tracking and on the assumption that different physicochemical processes between ENPs as well as between ENPs and collectors occur with different probabilities. In the first place, it is used to study the influence of different porosities on ENPs transport and retention inside porous media made of colloidal collectors. Then, homoaggregation, attachment and detachment processes are independently simulated within a porous media matrix of given porosity. Finally, the overall probability of ENPs retention as a function of the above mentioned processes is quantified using functional tests in the form of a αglobal(tref) retention parameter. The information about the variations of this parameter as a function of different factors is very important from an experimental point of view and helps to better explain results obtained with laboratory column studies.
Link to the article: https://archive-ouverte.unige.ch/unige:152746
HUL, Gabriela Jolanta et al. Effect of deposition, detachment and aggregation processes on nanoparticle transport in porous media using Monte Carlo simulations. In: Environmental Science: Nano, 2021. doi: 10.1039/D1EN00034A
27 Aug 2021