INVESTIGATION ON STABILITY AND TRANSPORT OF IRON OXIDE NANOPARTICLES (Fe3O4) STABILIZED WITH POLYACRYLIC ACID IN ONE-DIMENSIONAL POROUS MEDIA

Iron nanoparticles have been shown to be suitable for remediating contaminated aquifers. However, they usually aggregate rapidly and result in a very limited migration distance inhibiting their usefulness. This study employed polyacrylic acid (PAA) to stabilize magnetic iron oxide nanoparticles (Fe3O4). The mobility of iron oxide nanoparticles stabilized with PAA was also demonstrated on the basis of transport in porous media. The results showed that iron oxide nanoparticles stabilized with PAA have a size of about 100 nm. Moreover, results of UV-sedimentation experiments showed that iron oxide nanoparticle slurries stabilized with PAA with 2:1 weight ratio (1 g nano iron oxide and 2 g polyacrylic acid) have the lowest sedimentation. Also these slurries with high concentration had the most sedimentation compared with lower concentration slurries. In addition, the mobility of iron oxide nanoparticles stabilized with PAA in glass bead-packed columns (0.4 m length and 0.035 m inner diameter) was studied. In particular, the influence of flow-rate was addressed. Experimental results evidenced a good mobility of the iron oxide nanoparticles stabilized with PAA, with significant breakthrough under all explored experimental flow-rate conditions.