Remediation of Ni2+-contaminated water using iron powder and steel manufacturing byproducts

Steel manufacturing byproducts and commercial iron powders were tested in the treatment of Ni2 -contaminated water. Ni2 is a priority pollutant of so me soils and groundwater. The use of zero-valent iron, which can reduce Ni2 to its neural form appears to be an alternative approach for the remediation of Ni2 -contaminated sites. Our experimental data show that the removal efficiencies o f Ni2 were 95.15% and 94.68% at a metal to solution ratio of 20 g/L for commerc ial iron powders and the steel manufacturing byproducts in 60 min at room temper ature, respectively. The removal efficiency reached 98.20% when the metal to sol ution ratio was 40 g/L for commercial iron powders. Furthermore, we found that t he removal efficiency was also largely affected by other factors such as the pHs of the treated water, the length of time for the metal to be in contact with th e Ni2 -contaminated water, initial concentrations of metal solutions, particle s izes and the amount of iron powders. Surprisingly, the reaction temperature appe ared to have little effect on the removal efficiency. Our study opens the way to further optimize the reaction conditions of in situ remediation of Ni2 or othe r heavy metals on contaminated sites.