| Title |
Effect of Nitrogen Loading Rate on Simultaneous Removal of Organic matter , Nitrogen and Phosphorus in Swine wastewater Using Intermittently Aerated Activated Sludge System |
| Authors |
이원호(Won Ho Lee), 서인석(In Seok Seo), 이상일(Sang Ill Lee) |
| Abstract |
Intermittently aerated two and four-stage activated sludge system were investigated for removal of nutrients in swine wastewater taken from swine farm in Chungju area. Operating conditions were SRT 20days, HRT 24hrs and the ratio of aeration and nonaeration time was 1hr/1hr. Organics in influent were divided into total, filterable, readily biodegradable and soluble inert organics. Portions of particulate, readily biodegradable and soluble inert organics to the influent organics were 65.6, 24.4 and 5.4%. The effects of nitrogen loading on phosphorus removal and removal capability of nitrogen were evaluated. In intermittently aerated two-stage activated sludge system operation, with increase of nitrogen loading by two times, removal efficiency of T-N was sharply deteriorated, but amounts of removed nitrogen were unchanged. Whereas, removal efficiency of PO₄^(3-) -P was abruptly declined to result in 10% removal. In four-stages intermittently aerated activated sludge system operation, nitrogen loading rate in five step were 0.152, 0.23, 0.31, 0.35, 0.38㎏/㎥-day. Total nitrogen removal efficiency at each nitrogen loading rate were 95.5, 93, 91.6, 90.4 and 85% and total phosphorus removal efficiency were 93, 92, 91.5, 86.5 and 74.5% respectively. When nitrogen loading was increased gradually, total nitrogen removal efficiency was increased in comparion with a two-stage intermittently aerated activated sludge system. Also, phosphorus release-uptake mechanism was detected, but with a increasing of nitrogen loading rate, release-uptake mechanism was repressed. |