污水处理厂二沉池数值模型研究进展

数值模型模拟在污水处理厂二沉池设计、运行操作和优化方面具有无可替代的优势，对现有数值模型进行归纳与总结对实际应用中选择及建立模型至关重要。介绍了用于二沉池数值模拟的欧拉-拉格朗日模型、欧拉-欧拉模型和混合模型等多相模型的原理，对各模型的适用性进行阐述，总结其优点和不足；阐述了单相模型在污泥沉降中的应用原理，提出单相模型通过耦合单独的固相输运方程来描述污泥沉降运动规律，其在二沉池污泥浓度分布预测上优于多相模型；论述了污泥沉降速度模型研究现状，其中包含利用批量沉降试验的污泥间歇沉降模型和描述污水处理厂二沉池连续流污泥沉降模型；较为系统地综述了二沉池污泥负荷、几何结构、温度等因素对二沉池内水质模拟结果的影响；最后对污水处理厂二沉池数学模型的选择和沉降模型后续研究进行了展望。

Research progress of numerical model of secondary sedimentation tank in sewage treatment plant

Numerical model simulation has irreplaceable advantages in the design, operation, and optimization of the secondary sedimentation tank of the sewage treatment plant. It is very important to summarize existing numerical models for the selection and establishment of models in practical applications. The principles of multiphase models such as Euler-Lagrange model, Euler-Euler model, and Mixture model for numerical simulation of secondary sedimentation tank were introduced. The applicability of each model was described, the advantages and disadvantages of each model put forward, and the application principles of the single-phase model in sludge sedimentation explained. The single-phase model described the movement law of sludge sedimentation by coupling a single solid-phase transport equation, which was better than multiphase model in predicting the distribution of sludge mass concentration in the secondary sedimentation tank. The research status of the sludge sedimentation velocity model was discussed, including the model of intermittent sludge settlement using batch settlement test and the model of continuous flow sludge settlement describing the secondary sedimentation tank of the sewage treatment plant. The influence of sludge load, geometry structure, and temperature on water quality simulation of the secondary sedimentation tank was systematically reviewed. Finally, the selection of mathematical models for secondary sedimentation tank of the sewage treatment plant and future research on sedimentation models were prospected, to provide a theoretical basis and technical reference for the operation and design optimization of the secondary sedimentation tank of the sewage treatment plant.