Abstract

The study area is located on the western coastal region of Korea, partly had been reclaimed lands. Groundwaters of the coastal area show lower Eh and DO values (Eh: 0.57 V→0.13 V, DO; 9.7 mg/l→1.3 mg/l), and higher Fe concentrations (> 20 mg/l) than those of the inner land (< 0.3 mg/l), indicating that the redox condition of groundwater changes from oxic into suboxic/anoxic conditions as it flows from the inland toward the coastal area. In addition, Fe speciation of groundwater from the coastal area demonstrates that the most dissolved Fe exist as Fe²⁺, reflecting that groundwater is under the anoxic condition to sufficiently occur Fe reduction. According to the result of Fe extraction with the sediment samples from three wells (A, B, C), the sediments provide enough Fe³⁺ to occur the Fe reduction in the groundwater. Integrated all results of the groundwater and sediment, we infer that the Fe reduction to occur in groundwater is associated with the reclamation processes of the study area.

Keywords reclaimed lands, groundwater, suboxic/anoxic conditions, Fe speciation