Modeling the Transport of Hazardous Colloidal Suspensions of Nanoparticles Within Soil of Landfill Layers Considering Multicomponent Interactions

Abstract

The technological applications of the newly developed nanoparticles are continuously increasing. Nevertheless, their reduced size forming colloidal suspensions may facilitate the transport and bioaccumulation in the environment. The particular properties of each nanoparticle and its interaction with the dissolved organic matter (DOM) and the living organisms are important issues in this scenario. The landfill waste disposal method is still worldwide dominant. In the landfill, the nanoparticles can undergo phenomena such as leaching, agglomeration, flocculation, complexation, adsorption, dissolution, and neoformations. Among the concerns, it is recognized that the nanoparticles behave as carriers for the contaminants in the environment strongly impacting the water resources. This research is focused on the development of a mathematical model having an ability to predict the transports of TiO2, SiO2, ZnO, and CuO nanoparticles and their mutual interactions within soils commonly used as protective layers of controlled landfill for municipal waste disposal. A combined methodology based on numerical procedures using inverse method principles, and controlled experimental column experiments are carried out. First, the model parameters are determined, and second, the model is validated against numerical and experimental data. The model formulated newly address the interactions phenomena of colloidal suspensions of nanoparticles percolating through protective layers of landfill soils. It has been found that SiO2 nanoparticles presented the strongest deleterious effect on the efficiency of the soil protective layers, while ZnO plays a positive role promoting flocculation and complexation with soil particles and enhance their effectiveness.