Arsenite Reduction in Homogeneous and Heterogeneous Soil Columns Using Iron Nanoparticles

Arsenic is a toxic and dangerous pollution in groundwaters. A new, efficient and low-cost method for in-situ removal of the arsenic from aquifers is by using zero-valent iron nanoparticles which has been investigated in this research by three types of laboratory experiments including batch, homogenies soil column, and heterogeneous soil column tests. Batch tests have been mainly performed to investigate the effects of temperature and pH on the reaction process between the iron nanoparticles and arsenic. Then, the effect of soil grain sizes and flow velocity in the arsenic remediation by iron nanoparticles have been investigated in homogeneous and heterogeneous soil columns. Based on the experimental results useful graphs are presented to estimate the arsenic concentration for different time and different locations on the soil columns. The results showed the high capability of the zero-valent iron nanoparticles as a useful tool for removing the arsenic pollution from the groundwater. Injected nanoparticles in the soil column, especially in the lower flow velocities and fine-grained soils have been reduced hydraulic conductivity. Also, the results showed that as the flow velocity increases the remediation rate of arsenic pollution with iron nano particles decreases.