| Title |
Change in Influent Concentration of Domestic Wastewater from Separated Sewer and Biological Nitrogen and Phosphorus Removal of a Full Scale Air-vent SBR |
| Authors |
이장희 ( Jang Hee Lee ) ; 강호 ( Ho Kang ) |
| Keywords |
Combined sewer system; Full-scale SBR; Phosphorus removal; Separated sewer system; Simultaneous nitrification and denitrification ; SND |
| Abstract |
This study was carried out to investigate change in influent concentration of domestic wastewater flowed from a newly constructed separate sewer system (SSS) and biological nutrients removal efficiency of a full scale Air-vent sequential batch reactor (SBR, 600 m3/d). The average concentration of BOD5, SS, T-N and T-P from SSS were 246.5 mg/L, 231.6 mg/L, 42.974 mg/L, 5.360 mg/L, respectively which corresponds to 2.2times, 1.2times, 1.8times and 2.1times higher than those from the conventional combined sewer system (CSS). The removal efficiency of BOD5, SS, T-N, and T-P for the Air-vent SBR operated with influent from SSS averaged 99.1%, 99.0%, 91.2%, and 93.5%, respectively. Especially the respective nitrogen and phosphorus removal was 15% greater than that of the SBR operated with influent from CSS. Simultaneous nitrification and denitrification (SND) was observed in an aerobic reactor(II) as a result of DO concentration gradient developed along the depth by the Air-vent system. In order to achieve T-N removal greater than 90%, the C/N ratio should be over 6.0 and the difference between BOD5 loading and nitrogen loading rate be over 100 kg/day (0.130 kg T-N/m3·d). Even with high influent T-P concentration of 5.360 mg/L from SSS (compared with 2.465 mg/L from CSS) T-P removal achieved 93.5% which was 15.5% higher than that of the SBR with influent from CSS. This is probably due to high influent BOD5 concentration from SSS that could provide soluble carbon source to release phosphorus at anaerobic condition. In order to achieve T-P removal greater than 90%, the difference between BOD5 loading and phosphorus loading rate should be over 100 kg /day (0.130 kg T-P/m3·d). |