新型外循环厌氧反应器污泥沉降的数值模拟

结合EGSB及其它厌氧高效反应器的结构特征而开发的新型外循环厌氧反应器，在高上升流速下能有效控制污泥的流失，处理城市污水时获得了良好的效果。为了对新型外循环反应器的污泥沉降性能进行准确模拟和有效控制，利用质量平衡方程与颗粒污泥自由沉降理论，考虑沉降速率与浓度的关系，确定污泥沉降速率，从而建立了该反应器污泥沉降的弥散模型。对不同上升流速下的污泥浓度分布情况进行了模拟，其模拟结果与实测值吻合良好。然后纳入三相分离器分离效率（SE）的概念，实现了对出水SS的模拟，模拟数据的标准偏差小于6%。在确定污泥相对浓度的前提下，利用二次插值预测污泥层高度，结果表明不同上升流速的污泥层高度基本一致，但是同一高度不同上升流速的污泥浓度各不相同。

Simulation of sludge settling property in a novel outside cycle anaerobic reactor

A novel outside cycle anaerobic reactor was developed based on the characteristics of expanded granular sludge bed (EGSB) and other anaerobic reactors. It was demonstrated that the sludge wash-off at high liquid upflow velocities could be controlled efficiently and good performance was achieved during municipal wastewater treatment. In order to achieve accurate prediction and effective control of sludge settling property in the reactor developed, a dispersion model was established on the basis of mass balance and free settling theory of granular sludge, taking consideration of the relevance between sludge settling velocity and sludge concentration. The simulation results of sludge distribution was in good agreement with the measured results at different liquid upflow velocities. In addition, the concentration of suspended solids (SS) in the effluent was simulated by introducing the separation efficiency of three-phase separator. The standard deviation of the simulated data was less than 6%. Based on the relative concentration of the liquid-sludge mixture, the sludge blanket height could be calculated by quadratic interpolation. The sludge blanket heights were basically identical at various upflow velocities, while the sludge concentrations at the same height differed.