两级动态膜污水处理与能源回收耦合工艺研究

Due to the requirements of enhancing resource recovery efficiency and lowering energy consumption envolved in conventional wastewater treatment process, in this project a novel two-staged dynamic membrane process is developed for simultaneous wastewater treatment and energy recovery. The two-staged dynamic membrane process combines dynamic membrabe filtration reactor (DMFR) with anaerobic dynamic membrane bioreactor (AnDMBR). Due to different occurrence state of organics and nutrients in municipal wastewater, in DMFR high efficient concentration of organic matter is performed, while the produced permeate rich in nutrients is suitable for irrigation and so on, meanwhile because of high organic content and carbon and nitrogen ration in the concentrate high efficient anaerobic treatment and biogas recovery can be achieved in AnDMBR. Through batch tests and continous process experiments, the permeability and concentration properties of typical substances in municipal wastewater are illustrated, and the mechnism and method for the formation and stability adjusting of dynamic membrane are investigated, then mathematic evaluaton models are built based on resource recovery efficiency, carbon balance, energy expenditure and recovery balance, and finally high efficient and low energy consumption wastewater treatment technology is established resulting from the optimization of two-staged dynamic membrane process. It provides a new process pattern for decentralized wastewater treatment and resource and energy recovery.

针对污水处理中提高资源能源回收率和降低处理能耗的需求，本项目拟开展两级动态膜污水处理与能源回收耦合技术研究。以大孔径网材为膜基材，构建动态膜过滤反应器（DMFR）与厌氧动态膜生物反应器（AnDMBR）组合的两级处理工艺：第一级利用有机物和营养物在浓缩液和滤液中的不同分配比例，实现有机物高效浓缩和富含肥分滤液的灌溉利用；第二级利用浓缩液的高有机物浓度和高碳氮比，实现高效厌氧处理和生物气体回收利用。通过批式和连续工艺实验，揭示城市污水中典型物质组分的膜透过与浓缩规律，研究动态膜形成和稳定性调控的原理和方法，开发基于资源回收率、碳平衡和能源收支平衡的工艺评价模型，最终建立两级动态膜优化耦合的高效低耗污水处理工艺技术体系，为分散式污水处理和资源能源回收利用提供新的工艺模式。

针对污水处理中提高资源能源回收率和降低处理能耗的需求，基于新兴的低成本、低能耗动态膜技术，开发了以大孔网状材料为基材的平板式动态膜组件，成功构建了动态膜过滤反应器（DMFR）与厌氧动态膜生物反应器（AnDMBR）相耦合的两级处理工艺，阐明了污水中有机物高效浓缩和富含营养物质的滤液的灌溉利用性能、厌氧处理有机浓缩液回收生物能源气体的效能。研究中揭示了城市污水中典型物质组分的膜透过与浓缩规律，考察了动态膜形成和稳定性调控的措施，探明了膜材料性质、颗粒载体投加及运行操作条件等对工艺效能的影响，应用物料平衡和能量平衡的方法评价了耦合工艺的技术经济性。研究结果表明，典型生活污水中颗粒物粒径分布广泛，平均粒径在40~60 μm的范围内；分离膜孔径大于5μm时，COD、氨氮、TN和TP分别占总量的53.2%、20%、7.1%和38.2%，因污染物尺度分布的不同而呈现出选择性截留的特性；应用活性炭为载体预涂动态膜的方法，DMFR可以实现高通量（40~60 L/m2h）下连续运行，周期可达30-50 h，采用曝气反冲洗可以实现通量恢复，单周期COD浓缩液高达1500~3000 mg/L，体积浓缩倍数大于20，COD的截留率接近60%，TN透过率>70%，TP透过率>60%；AnDMBR处理一级DMFR的浓缩液（COD=2000 mg/L）时，通量为5-6 L/m2h，出水COD<100 mg/L、浊度<20 NTU，膜过滤性能良好（过滤周期=20~60 d），但是产气率相对较低（<0.1 LCH4/gCOD）。针对浓缩液中颗粒物含量高且水解效率低、产气性能尚需优化的问题，尚需要继续深入研究浓缩液厌氧消化性能提升的强化调控策略，进一步提升两级动态膜工艺的效能和应用潜力。