Removal of Nitrate in Groundwater by Zero- Valent Iron Packed Columns

Groundwater polluted by nitrate has become a serious problem, and more attentions have been paid to methods of nitrate remediation. In this paper, factors affecting removal of nitrate were studied by continuous- flow zero- valent iron packed columns, such as pH and dissolved oxygen. The operation term of the column and the treatment of groundwater were researched. The results showed that nitrate removal strongly depended on initial pH value. Decreasing the initial pH resulted in increasing nitrate removal, and the removal rate of nitrate was high up to more than 90% when initial pH value was 2. Meanwhile, dissolved oxygen did not inhibit nitrate removal. It has been indicated that application of the method by the iron packed column can successfully remove the nitrate pollution in groundwater.