微涡流絮凝工艺处理高浊水的数值模拟与响应面优化试验

针对微涡流絮凝工艺处理高浊水开展连续性工艺优化研究，采用计算流体力学（CFD）数值模拟软件，探究不同流量（流速）下絮凝区液流状态变化，确定最佳絮凝时间；应用响应面Box-Behnken设计方法，研究流量、混凝剂投加量与回流比及其交互作用对微涡流絮凝工艺处理高浊水效果的影响。结果表明：随着流量（流速）增大，絮凝区内湍动能、有效能耗、速度梯度及其变化率逐渐增大，但流速过大会导致絮凝时间不足，最佳流量为4.2~7.0 m³/h（最佳流速为0.41~0.67 m/s）；回流比是微涡流絮凝工艺的极显著影响因素，其次是混凝剂投加量，最后是流量，三者间具有协同作用；微涡流絮凝工艺处理高浊水的最佳工艺参数，流量为5.9 m³/h，混凝剂投加量为34.8 mg/L，回流比为0.8，浊度、UV₂₅₄、COD_Mn去除率分别可达99.23%、95.03%、71.42%。优化后的微涡流絮凝工艺为高浊水处理提供了新途径，具有一定的应用前景。

Numerical simulation and response surface optimization of micro-vortex flocculation process for high turbidity water treatment

The optimization of continuous process was conducted for the treatment of high turbidity water by micro-vortex flocculation process. The computational fluid dynamics (CFD) numerical simulation software was applied to explore the changes of liquid flow state in the flocculation area under different flow rate (flow velocity) so as to determine the optimal flocculation time. By using response surface Box-Behnken design method, the effects of flow rate, coagulant dosing and reflux ratio and their interactions on the treatment effectiveness of high turbidity water by micro-vortex flocculation process were studied. The research showed that as the flow rate (flow velocity) increased, the turbulent kinetic energy, effective energy consumption, G-value and its rate of change in the flocculation zone gradually increased, but too excessive flow velocity could lead to insufficient flocculation time, and thus the optimal flow rate range was 4.2-7.0 m3/h. or the optimal flow velocity was 0.41-0.67 m/s. The reflux ratio was a highly significant factor affecting the micro-vortex flocculation process, followed by the coagulant dosage and flow rate, with a synergistic effect between the three. The best process parameters of micro-vortex flocculation process for treating high turbidity water were: flow rate 5.9 m3/h, coagulant dosage 34.8 mg/L, and reflux ratio 0.8; the removal rates of turbidity, UV254 and CODMn were 99.23%, 95.03%, and 71.42%, respectively. The optimized micro-vortex flocculation process could provide a new way for high turbidity water treatment technology with certain application prospects.