Improving urban run- off quality using iron oxide nanoparticles with magnetic field

Run-off from road surfaces is a major source of pollution in the environment. The aim of this study was to investigate the efficiency of nano iron oxide under a magnetic field to improve urban run-off quality. Experiments were conducted in a 50mm diameter column made of Plexiglass in which 20cm deep stainless steel wool was used as the medium bed. A pair of magnets, each with 0.7T magnetic charge density, was installed around the column. The particle size of the iron oxide was determined by X-ray diffraction (XRD) analysis. Atomic absorption spectroscopy, spectrophotometer, turbidimeter, and pH meter were used to measure heavy metals, nitrate and phosphate, turbidity and pH, respectively. Results from XRD analysis revealed that the average nanoparticle size was 32nm. The average removal efficiency for turbidity, Pb, Zn, Cd, and phosphate were 41.5, 93.9, 96.2, 88.4, and 87.4%, respectively. However, nitrate was not removed from the column tests. The results of this study showed that nano iron oxide in the presence of magnetic field has the potential to improve urban run-off quality. However, for further reduction of turbidity and nitrate removal other options should be considered.