细微泥沙在活性污泥系统中的迁移模型

Modelling the Migration of Influent Fine Sediment Through Activated Sludge System

摘要:

在不同进水细微泥沙负荷条件下，以质量守恒为基础，建立了活性污泥系统中细微泥沙的迁移模型.研究表明，影响期混合液中细微泥沙浓度与进水细微泥沙浓度、细微泥沙可悬浮比例、污泥龄、水力停留时间及影响时间有关，恢复期混合液中细微泥沙浓度与恢复开始时混合液细微泥沙浓度、污泥龄、及恢复时间有关.通过模型计算影响期各系统中细微泥沙浓度平均相对误差为11.7%~24.6%，恢复期为29.1%~46.0%；污泥中挥发性悬浮固体含量平均相对误差为0.9%~7.3%；恢复期为2.3%~34.4%.混合液中细微泥沙最大浓度、细微泥沙淤积速率与进水细微泥沙负荷呈正比关系.

关键词:城市污水处理厂; 活性污泥; 细微泥沙; 迁移模型

Abstract:

A simple model based on mass balance was constructed for the prediction of fine sediment migration in activated sludge reactor under different influent fine sediment load. The results shown that, during the influence period, the predicted fine sediment concentration was mainly effected by concentration of influent fine sediment, proportions of suspended fine sediment, sludge age, hydraulic retention time and impact time. During the recovery period, however, it was mainly effected by initial fine sediment concentration, sludge age, and recovery time. The relative errors of the predicted fine sediment concentration during the influence and recovery period were between 11.7% and 24.6% , 29.1% and 46.0%, respectively. The relative errors of volatile suspended solids ratio in sludge during the influence and recovery period were between 0.9%and 7.3%, 2.3%and 34.4%, respectively. The maximum fine sediment concentration in mixed liquor and deposition rate of fine sediment are proportional to influent fine sediment load.

Key words:wastewater treatment plants; activated sludge; fine sediment; migration model