Zou Zhi-hong, Zhang Wei, Sui Jun
School of Economics and Management, Beihang University, Beijing 100083, China.
Huan Jing Ke Xue. 2007 May;28(5):1016-9.
The problem that the present sediment theory does not consider sludge recirculation effect on the efficiency of particle settling is studied. Based on the longitudinal mixing settling theory, an imperfect sediment model that takes reflux ratio in consideration is built. According to the established model, the study analyzes the effect of sludge recirculation taken by suction dredge on particle setting, in horizontal sedimentation tank. Specifically, the relation between overplus of sewerage suspension and sedimentation rate was chosen as an example. Shown as a result, when sludge recirculation is not taken in consideration, efficiency of particle settling is 72.8%. However, when sludge recirculation increases from 0.5 to 3.0, efficiency of particle settling decreases from 71.1% to 50.9%, which is smaller than efficiency of particle settling without recirculation; and when sludge recirculation is 3.0, efficiency of particle settling is 50.9%, which is approximately 30% less than efficiency of particle settling without recirculation. So, sludge recirculation make efficiency of particle settling is smaller than efficiency of particle settling without recirculation, and the efficiency of particle settling reduces with the increase of reflux ratio.
研究了目前的泥沙理论未考虑污泥回流对颗粒沉降效率影响的问题。基于纵向混合沉降理论，建立了考虑回流比的不完善沉降模型。根据所建立的模型，该研究分析了吸泥机污泥回流对水平沉淀池颗粒沉降的影响。具体而言，以污水悬浮物余量与沉降速率之间的关系为例。结果表明，当不考虑污泥回流时，颗粒沉降效率为72.8%。然而，当污泥回流比从0.5增加到3.0时，颗粒沉降效率从71.1%降至50.9%，低于无回流时的颗粒沉降效率；当污泥回流比为3.0时，颗粒沉降效率为50.9%，比无回流时的颗粒沉降效率低约30%。因此，污泥回流使颗粒沉降效率低于无回流时的颗粒沉降效率，且颗粒沉降效率随回流比的增加而降低。
