One-dimension flux model for the secondary settling tank based on the mass conservation

作者：Zhang Dai Jun; Li Zhen Liang; Zhang Tian; Cao Hai Bin

来源：China Environmental Science, 2006, 26(SUPPL.): 40-44.

Based on the mass conservation law, a one-dimensional flux model for the Secondary Settling Tank (SST) with varying cross-sectional areas was led out. Takacs function was adopted for describing the settling at low concentration and the zone settling, and a compression settling velocity function for the compression settling. The model of sludge mass conservation in unit layer was still very stable under the disturbances of influent flow rate, influent solid concentration, return flow ratio and their combination. The simulated SST effluent sludge concentration and return flow sludge concentration were 16.40 mg/L and 7.01 g/L respectively, coinciding a little with actually measured value range of 15~19 mg/L and 6.46~8.32 g/L. The forecasted sludge blanket height was 0.55 m, being the same relatively with the actually measured value 0.45 m. Meanwhile, the suitable selection of the number of SST unit layer and the simulated time step could basically avoid the simulating distortion. The model dividing the settler into 30 or more unit layers would be able to accurately represent the SST performance.

• 出版日期2006