Paper Title
Degradation of Nitrate by Modified Surface of Nano-Zero Valent Iron in Flow through Permeable Reactive Barrier: Different Configurations

Permeable reactive barrier (PRB) is one of the well-known technologies for in situ nitrate removal from groundwater owing to their effective operation and maintenance costs. This work aims using modified surface of nanoscale zero valent iron (known as bimetallic nano-Fe/Cu particles) as a reactive material in the porous media of PRB for nitrate removal. In order to simulate the real situation of PRB, column experiments were conducted in this study under different configurations. The effect of one layer, two layers and different thickness layers of nano-Fe/Cu particles was investigated. 10 g of nano-Fe/Cu particles were applied in each column. The initial nitrate concentration was 200 mg/L. Solid analysis was performed after dismantling using X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer- Emmett-Teller (BET) surface area analysis to characterize nitrate removal mechanism in each column. The results revealed that using double 5-cm high layers of bimetallic nanoparticles showed the highest nitrate removal efficiency. In addition, high accumulation of ammonium was observed during (nano-Fe/Cu)/sand column experiments. Little formation of nitrite was detected during the initial stages of (nano-Fe/Cu)/ sand columns whereas relatively high accumulation was obtained at later stages. Keywords - Nanoscale zero valent iron (nZVI); Porous media; Nitrate removal; Packed sand column.