| Title |
Characteristics of Nutrients in a Supernatant during the Intermittently Aerated Sludge Digestion |
| Authors |
윤현식(Hyun Sik Yoon),최용수(Yong Su Choi),이영대(Young Dae Lee),홍석원(Seok Won Hong),정익재(Ik Jae Chung) |
| Abstract |
In general a waste activated sludge is biologically stabilized by either aerobic or aerobic digestion. Typical problems associated with these two processes include high energy requirement, capital cost, and high load to the main wastewater treatment process due to returned digestion supernatant. To overcome these problems in conventional digestion processes, the intermittently aerated sludge digestion, which is operated under combined aerobic and anoxic condition, has been studied for another alternative. In order to understand the behaviors of nutrients in a supernatant of sludge digestion, intermittently aerated batch and continuous digestion experiments were investigated in this study. In a batch digestion, it is shown that nitrogen and phosphorus concentration in the intermittently aerated digestion are less than those in controlled batch digestions: anaerobic digestion without air supply and aerobic digestion with continuous air supply. The endogenous nitrate respiration following the nitrification and the P-uptake by the residual microbes are alternatively occurred in the intermittently aerated digestion. In the continuous digestion, nitrogen and phosphorus concentration in the effluent were examined under air on/off operating condition. |