Pore-network modeling of colloid transport and retention considering surface deposition, hydrodynamic bridging, and straining

Colloid transport and retention in porous media is a common phenomenon nature. However, mechanisms are not fully revealed based on macroscale experimental observations. The pore-network model (PNM) an effective method to account for the pore structure of medium provides direct connection between pore-scale phenomenon. In this study, PNMs with cylindrical throats spherical bodies used upscale water flow colloid from pore- macro-scales, taking into consideration surface deposition, hydrodynamic bridging, straining. Numerical experiments were conducted investigate effect size, initial concentration, velocity behavior. Results show that bridging straining produce hyper-exponential profiles, whereas deposition due nanoscale roughness charge heterogeneity yields exponential or uniform profiles. Hydrodynamic will happen when concentration lower than some threshold value (rp ≤ 500 nm, C0 7.1 × 1014 Nc/m3, U0 0.1 m/d under conditions study). relative importance comparison increases increase velocity. PNM useful tool discriminate different predict behavior media.