济南市某水厂沉淀气浮池气浮区运行效果评估及计算流体力学模拟

Operation evaluation and computational fluid dynamics simulation of the gas floatation area of a sedimentary gas floatation pond in a water plant in Ji’nan City

济南市某水厂以黄河水为原水,近几年黄河水受污染日益严重,水厂原有常规工艺难以使出水达标。2010年对水厂进行升级改造,改造规模20万m^3/d,将原有的平流式沉淀池升级改造为沉淀气浮池。改造后沉淀气浮池对浊度、氨氮、藻类以及MIB去除效果明显优于改造前,但对CODMn的去除没有明显优势。利用CFD对沉淀气浮池气浮区进行数值模拟,并结合取样检测结果进行运行评估。结果表明:沉淀气浮池气浮区池体结构合理,流场特征良好,建议溶气压力为0.40MPa,条件允许下,可提高溶气压力到0.45MPa。

A water plant takes the Yellow River water as raw water,due to the increasingly serious pollution of Yellow River in recent years,the original technology is difficult to make the effluent up to the standard.In 2010,the general treatment capacity of 200 000m^3/d was upgraded to the water plant.It was mean that the original flat-flow sedimentation tank was upgraded to the sedimentary gas floating tank.Its effect on turbidity,ammonia nitrogen,algae and MIB were obviously better than before transformation,but the removal of CODMnwas not obviously advantageous. Computational fluid dynamics software was used to simulate the air floatation area of the sedimentary gas floatation tank and to evaluate the operation based on the results of sampling and testing. The results show that the structure of the air floatation area of the sedimentary gas floatation tank is reasonable and good flow field characteristics.It is suggested that the dissolved gas pressure is at 0.40MPa.If the condition allows,the dissolved gas pressure may be increased to 0.45MPa.