厌氧膜生物反应器常温处理污水的三维模型及调控

Aerobic activated sludge processes require great aeration energy and produce large amounts of residual sludge. The aim of this research is to develop anaerobic membrane bioreactors (AnMBRs) to replace aerobic activated sludge technologies in the removal of organic matters in domestic wastewater treatment. In order to develop new technologies, methods based on models are more comprehensive，efficient and deep, compared to methods based on experiments. A three dimensional anaerobic digestion model (ADM) is a tool for understanding the operation of anaerobic membrane bioreactors and increasing the reactors’ stability. However, a three dimensional hydraulic model is the basis of the ADM model. And accurate characterization of sludge viscosity is the precondition for the building of the hydraulic model. This research will first characterize the viscosity of sludge with high sludge concentration in an AnMBR. Then a three dimensional hydraulic model will be built. A mass transfer model will be built by combining mass transfer theory and the hydraulic model. The combination of the mass transfer model and carbon metabolism network will be applied to build a three dimensional ADM model in the reactor. Based on the three dimensional ADM model, reactor operation parameters will be obtained to supply stable superior effluent, which can be applied to obtain desired effluent.

好氧活性污泥法具有曝气能耗高、剩余污泥产量大的先天缺陷。本研究的根本目的是：开发AnMBR作为活性污泥法城市污水处理替代工艺。要探索新工艺，基于模型的探索方式显然要比基于大量试验的方式来的系统、高效和全面。建立AnMBR中三维ADM模型是掌握反应器运行特性、提高反应器稳定性的重要工具，而反应器中三维流体力学模型是建立三维ADM模型的重要基础。在三维流体力学模型中准确地定义反应器内高浓度污泥的粘度是建立该模型的先决条件。本项目利用插值法实现对高污泥浓度污泥粘度的定义，采用计算流体力学理论完成反应器的三维流体力学模型的构建；将该三维流体力学模型与传质扩散理论结合获得质量传递模型；将该质量传递模型与在碳代谢流网络图基础上建立的厌氧消化数学模型结合获得模拟反应器内部有机物降解过程的三维ADM模型。利用模型给出反应器出水水质优越、稳定性强的操作参数。在此基础上，对反应器进行调控以实现预期的出水效果。

厌氧膜生物反应器是近年的研究热点，其可以克服部分污水不利于形成厌氧颗粒污泥的缺陷从而在反应器中形成高浓度的厌氧污泥。研究以控制厌氧膜生物反应器的膜污染以及通过建立反应器的数值模型为目标来掌握厌氧膜生物反应器的运行特性。研究实现了比现有厌氧膜生物反应器通量高2-3倍的通量（15-20 LMH），同时反应器中的跨膜压差小于20kPa。采用的低成本滤布避免了更高过滤通量的需求。提出了快速、准确估算复杂厌氧消化数学模型所有参数的智能算法。在此基础上，实现了在反应器三维数值模型的构建。反应器中的污泥完全降解了反应器入水的有机物。出水COD 成分均为胞外多聚物。