Nitrate-contaminated groundwater has become a major issue of public health concern in recent years. As reported from various research groups, zero-valent iron-based process exhibits great potential for nitrate removal. However, the effects of various water qualities on this process have not been clearly understood, including natural organic matter, calcium, sodium, chloride and carbonate ions. In this study, CO2 was bubbled into Fe0-contained solution to create an acidic environment favorable to Fe0 corrosion. Results showed that nitrate removal was inhibited significantly in the presence of humic acid. The blockage of reactive sites of Fe0 might occur from adsorption of humic acid. Moreover, calcium was found to inhibit nitrate removal as well. Interestingly, chloride plays a role of promoting the reduction of nitrate. Concerning other species, sodium and carbonate ions imposed only slight effect on nitrate removal.
