초록
The experimental conditions and relationships between parameters such as organic matter, aeration volume, aeration time, and precipitation time for the effective treatment of domestic wastewater were investigated. With the batch systems, the adsorption amount of unit microbe was measured with the change of MLSS concentration, precipitation time, and aeration amount. Theoretical adsorption amount of microbes was then numerically formulated by use of a SPSS multiple analysis as follows: $$Y=-0.0106(X_1)+0.07310(X_2)+42.705(X_3)+62.700$$ In this study, the amount of organisms to be removed in the range of MLSS concentration 2,000~4,500 mg/l were examined. In order to investigate the optimal condition of nitrification, the upper water in the biosorption stage was used as the initial experiment water. The results showed that the C/N ratio was 1.5 and the reaction time for the optimal nitrification was 1.5 hr. When the adsorption efficiency for microbe biosorption was 66%, the optimum denitrification efficiency was 83.3%. When the optimum parameters obtained from the batch experiment were applied to the lab-scale operation, the total retention time from the flow-in to flow-out was 10 hours and the removal efficiency was 93.8% for $COD_{cr}$ and 80.9% for TN. For the full-scale operation, the total retention time was 9.0 hours and the removal efficiency was 94.4% for BOD, 89.6% for $COD_{cr}$, 88.0% for TN, and 86.2% for TP.
