Organic matter, anion, and metal wastewater treatment in Damyang surface-flow constructed wetlands in Korea

Surface-flow wetlands constructed with Acorus and Typha plants, connected to a wastewater treatment plant, were investigated with respect to organics (dissolved organic matter), anions (nitrate, sulfate, and phosphate), metals (Cu, Ni, Zn, Fe, and Mn), and metalloids (As). The results of the research indicated: (1) effluent organic matter (EfOM), based on dissolved organic carbon (DOC), was not efficiently removed by the wetlands. However, the hydrophobic, transphilic, and hydrophilic EfOM fractions varied throughout the wetlands, as identified by XAD-8/4 resins. (2) Nitrate, as compared to sulfate and phosphate, was efficiently removed, especially in the Typha wetland pond that had long retention time, under anoxic condition. (3) Most of the heavy metals were ineffectively removed via the wetland ponds. However, the iron concentration increased in the Typha wetland pond, which was probably due to its reduction under anoxic condition.