| Popis: |
A novel mathematical model was developed to describe the transport of nanoparticles in water saturated, homogeneous porous media with uniform flow. The model accounts for the simultaneous migration and aggregation of nanoparticles. The nanoparticles can be found suspended in the aqueous phase or attached reversibly and/or irreversibly onto the solid matrix. The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was used to account for possible repulsive interactions between aggregates allowing for both reaction-limited aggregation (RLA), and diffusion-limited aggregation (DLA) cases to be considered. The governing coupled partial differential equations were solved initially by employing adaptive operator splitting methods, which decoupled the reactive transport and aggregation into distinct physical processes. Subsequently, the resulting equations were treated individually with proper use of either a finite difference scheme or a specialized ordinary differential equations solver. The results from various model simulations showed that the transport of nanoparticles inporous media is substantially different than the transport of conventional biocolloids. In particular, aggregation was shown to either decrease or increase nano particle attachment onto the solid matrix and to yield either early or retarded breakthrough. Finally, useful conclusions were drawn regarding the particle distribution density at various points in time and space. |
