Transport of surface stabilized zero-valent iron nanoparticles in 2-D flow system packed with porous media

ENVR 33

S. R. Kanel, srk0001@auburn.edu, R. R. Goswami, T. P. Clement, M. O. Barnett, and D. Zhao. Department of Civil Engineering, Auburn University, 238 Harbert Engineering Center, Auburn, AL 36849
Zero-valent iron nano particles (INP) were synthesized and stabilized with poly-acrylic acid to yield stabilized INP (S-INP). A two-dimensional physical model is developed and used to study the transport of these nano materials such as pristine INP and S-INP in a porous media under saturated conditions at fixed flow rates and initial concentration of nano materials. Transport data for INP, S-INP and a non-reactive tracer were collected under similar flow conditions. The results show that the transport of S-INP was the same as trace whereas bare INP did not show transport characteristics. Interestingly, it was observed that the S-INP plume migrated downwards as it transited horizontally in the physical model, indicating that the density of the suspension affected the transport of S-INP. The variable-density groundwater flow model SEAWAT was used to model the observed density-driven transport patterns. The data clearly show the importance of density effects, which cannot be fully discerned using one-dimensional column experimental setups. Finally, we have also shown that the numerical model SEAWAT can be used to predict the density-driven transport characteristics of S-INP in groundwater aquifers.