| Title |
Removal of Nutrients from Domestic Wastewater Using Intermittently Aerated Activated Sludge Systems Supplemented with Fermented Settled Sludge |
| Authors |
원성연 ( Won Seong Yeon ) ; 이상일 ( Lee Sang Il ) |
| Keywords |
Intermittent aeration; Dynamic flow; External corbon source; Denitrification |
| Abstract |
In this research, a 2-stage intermittently aerated activated sludge system(IA) and intermittently aerated dynamic flow activated sludge system(DF) were investigated for the removal of nutrients in domestic wastewater. Wastewater was characterized by low C/N(organics/nitrogen) ratio. COD,,, BOD_(5), TKN and TP concentrations of domestic wastewater were 235, 47, 32 and 5.4 ㎎/L , respectively. Three sets of LA and one set of DF were operated. Three of four systems were added with fermented settled sludge taken from primary settling tank as an external electron donor and the other(IA) for control reactor was operated without addition of electron donor. All systems were operated at same sludge retention time of 20 days and hydraulic retention time of 12hrs. The supplemental electron donor was supplied into the anoxic mode. A higher denitrification rate was observed from the reactors with fermented settled sludge as an electron donor for denitrification compared to that of without addition of organic source. The result of this study indicates that the settled primary sludge, if the fermented at the acid stage, was an excellent electron donor for denitrification. 81% of TN and 80% of TP were removed from the systems with the supplemental organic source added. However, the control reactor without addition of electron donor showed only 39% of TN and 43% of TP. |