【作者】 谭冲；

【导师】 李建政； 马放；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2013， 博士

【摘要】 生物膜法是污水生物脱氮处理技术之一。填料作为生物膜的载体，对生物膜的生长、结构和活性均具有显著影响。适宜的填料可促进生物膜的形成和系统的启动过程，提高系统的处理效能，降低运行成本。因此，对于新型填料的开发一直是污水处理领域的热点研究问题。聚氨酯（PU）填料具有高孔隙率、高比表面积和低密度等诸多优点，可显著提高系统的生物量和处理效能，已在各种有机废水处理中得以应用。但关于PU填料生物膜系统的脱氮效能及其生物学机制仍然缺乏研究，限制了其在污水生物脱氮处理中的推广应用。本文采用自主研发的改性PU填料（MPU），构建了批式生物膜反应器（SBBR）污水生物膜脱氮系统，建立了基于改性PU填料的硝化反硝化动力学模型，解析了填料负载的生物膜硝化功能菌群的分布特征，为经济高效生物膜脱氮系统的构建提供了材料、技术和理论支撑。在对MPU生物膜脱氮效能和生物学机制研究的基础上，针对高氨氮和低C/N废水的处理对PU进行了改性试验制备出负载电气石聚氨酯填料（TPU）和负载淀粉聚氨酯填料（SPU），并考察了以其构建的生物膜系统的氨氧化和脱氮效能。与采用常规聚乙烯（PE）填料构建的SBBR的对比实验研究表明，在相同运行条件下启动并达到运行稳定后，以MPU填料构建的SBBR（MPU-SBBR），其氨氮和COD去除率与普通PE填料构建的SBBR（PE-SBBR）相当，分别约为92.0%和85.5%，但MPU-SBBR系统可在15d内启动成功并达到稳定运行，较PE-SBBR系统提前了21d，大幅缩短了生物膜脱氮系统的启动周期。对生物膜脱氮系统影响因素的研究表明，MPU-SBBR系统具有良好的脱氮效能。在常温（20℃）条件下，其生物脱氮的适宜条件为HRT6h、pH7.0~8.5和DO1.5~2.5mg/L，总氮去除率为75.4%左右。在DO维持在较低的0.5~1.0mg/L水平时，MPU-SBBR系统的总氮去除率仍可维持在70.6%上下。pH8.2最利于亚硝酸菌群的富集，系统的氨氮去除率可达90%以上。在水温为12℃时对硝酸菌群（NOB）受到较亚硝酸菌群（AOB）更大的抑制作用，系统会发生了亚硝酸盐的累积，而温度升高到15℃以上时，这一抑制作用逐渐得以消除，系统对氨氮的去除率随之提高。硝化反硝化反应动力学分析表明，MPU生物膜系统在脱氮过程中的硝酸盐饱和常数K D大于传统活性污泥系统，保持较高硝酸盐浓度有利于MPU生物膜系统的稳定脱氮。生物膜的功能微生物分析表明，在HRT6h、pH7.0~8.5和DO1.5~2.5mg/L条件下，MPU-SBBR生物膜的微生物多样性要显著高于其他工况，优势亚硝酸菌和硝酸菌分别以亚硝化单胞菌（Nitrosomonas sp.）和硝化螺旋菌（Nitrospira sp.）为主，而反硝化细菌则以陶厄氏菌（Thauera sp.）和红假单胞菌（Pseudomonas sp.）占据优势。进水C/N比（C和N分别以COD和总氮计）对系统短程硝化反硝化影响显著，C/N比越大，生物膜的生物多样性越高，最佳的氨氮去除率92.9%和总氮去除率79.0%分别出现在C/N比分别为5.0和1.8时，其硝化功能优势微生物为氨氧化菌（Unculturedammonia-oxidizing bacterium）、Nitrospira sp和硝化杆菌（Nitrobacter sp.），反硝化优势菌为Pseudomonas sp.，工程中可以通过对进水C/N比的调节实现对系统氮素转化和总氮去除的调控。针对高氨氮污水的处理，采用电气石负载对PU进行了改性而制备一种新型载体材料TPU。研究表明，与改性前的PU相比，TPU填料表面更粗糙，持水倍率更高，可对微环境pH进行有效调节。电气石良好的热电性和压电性进一步提高了填料的吸附性能，使TPU填料更有利于硝化细菌的富集。TPU填料生物膜中的亚硝酸细菌和硝酸细菌在数量上比PU填料生物膜分别提高了62.9%和46.4%，可显著强化系统的硝化作用。对于COD和氨氮浓度分别为600~650mg/L和230~250mg/L的污水，与PU生物膜处理系统相比，TPU生物膜处理系统的氨氮去除率提高了12.3%。针对低C/N比污水，采用淀粉负载对PU进行了改性而制备出另一种新型载体材料SPU。淀粉的负载对低C/N比污水脱氮起到了良好的持续调节作用。对于COD和C/N比分别为150mg/L和2.5的污水，SPU-SBBR系统表现出了更好的脱氮效率（65.3%），与聚己酸内酯(PCL)构建的SBBR系统（53.3%）相比，其总氮去除率提高了12%。更多还原

【Abstract】 Biofilm process is one of biological nitrogen removal technology inwastewater treatment. The filler as a biological carrier, have significantinfluences on the growth, structure and activity of the biofilm. The suitable fillermay promote formation of biofilm and start-up of the system, improve the systemtreatment efficiency, reduce the operation cost. Therefore, the development ofnew filler has been a hot research in the field of wastewater treatment.Polyurethane (PU) filler has many advantages such as high porosity, anappropriate pore size, low density and so on. PU filler has been successf ully usedin a variety of organic wastewater treatment. But the nitrogen removal efficiencyof PU biofilm system and its biological mechanism is still a lack of research,which limits its popularization and application in nitrogen removal of wastewatertreatment. This experiment regarded self-developed modified PU filler (MPU),build a sequencing batch biofilm reactor (SBBR) biofilm wastewater nitrogenremoval system, and investigate the nitrogen removal efficiency, establish thenitrification and denitrification kinetic model, analysis distributioncharacteristics of the nitrifying functional bacteria, provides the material,technical and theoretical support for the construction of efficient biologicaleconomy biofilm system. Based on the nitrogen removal efficiency andbiological mechanism, Modification of PU was studied further to develop newPU load tourmaline and PU load starch to treat high ammonia wastewater andlow C/N ratio wastewater and investigate ammonia oxidation and nitrogenremoval efficiency.The contrast experimental study with the conventional polyethylene filler(PE) showed that, in the same operating conditions and after achieving stableoperation, the removal efficiency of ammonia nitrogen and the COD of SBBRsconstructed by MPU (MPU-SBBR) and constructed by normal PE (PE-SBBR)were92.0%and85.5%, respectively. But the MPU-SBBR system within15d toachieving stable operation ahead of21d by the PE-SBBR system, it significantlyshorten the start-up period of biofilm system.The study of influencing factors on the biofilm nitrogen removal systemshows that, MPU-SBBR has good nitrogen removal efficiency. At roomtemperature (20℃) conditions, the optimum biological nitrogen removalconditions is HRT6h, pH7.0~8.5, DO1.5~2.5mg/L, total nitrogen removalefficiency is about75.4%. The DO maintained at a relatively low level of0.5~1.0mg/L, total nitrogen removal efficiency of MPU-SBBR system can be maintained at70.6%. The pH8.2is the most beneficial to accumulate the nitrifying bacteria,the ammonia nitrogen removal efficiency can reach over90%. With watertemperature was12℃the nitrite-oxidizing bacteria (NOB) was more inhibitedthan ammonia-oxidizing bacteria (AOB), the system had the accumulation ofnitrite, and when the temperature up to15℃, the inhibitory effect on AOB andNOB by temperature have gradually eliminated, ammonia nitrogen removalefficiency of system increased. Nitrification and denitrification reaction kineticmodel analysis showed that, nitrate saturation constant of MPU biofilm system indenitrification process was bigger than conventional activated sludge system, anda high nitrate concentration was benefit to stable remove nitrogen in MPUbiofilm system.The microbial biofilm analysis indicates that, with condition of HRT6h, pH7.0~8.5, DO1.5~2.5mg/L, microbial diversity of MPU-SBBR biofilm wassignificantly higher than that in other conditions. The advantages of AOB andNOB were Nitrosomonas sp. and Nitrospira sp. respectively, the advantages ofdenitrifying bacteria were Thauera sp. and Pseudomonas sp..The influent C/Nratio (C and N represent COD and total nitrogen respectively) had a significanteffects on short-cut nitrification and denitrification. The higher C/N ratio, thehigher biofilm biodiversity. The best ammonia nitrogen removal efficiency was79%when C/N ratio was5and the best total nitrogen removal efficiency was92.9%when C/N ratio were1.8. The advantages of nitrifying bacterial wereuncultured ammonia-oxidizing bacterium, Nitrospira sp. and Nitrobacter sp.,denitrifying bacteria was Pseudomonas sp.. The nitrogen transformation and totalnitrogen removal can be controlled by adjusting the influent C/N ratio in theproject.For the treatment of high ammonia nitrogen wastewater, the tourmaline wasload on the PU to prepare new TPU materials. Research shows that, comparedwith the unmodified PU, TPU filler surface was rougher, water holding rate washigher, can adjust effectively to the pH microenvironment, and its goodpyroelectricity and piezoelectricity further improve the adsorption properties toenrich the nitrifying bacteria. Compared with PU biofilm, the number of AOBand NOB in the TPU biofilm increased by62.9%and46.4%, respectively, whichsignificantly enhanced nitrification. In treating COD concentration of600～650mg/L and ammonia nitrogen concentration of230～250mg/L wastewater,compared with PU biofilm system, ammonia nitrogen removal efficiencyincreased by12.3%in TPU biofilm system treating.For low C/N ratio sewage, the starch was load on the PU to develop a newSPU material. The SPU filler can take a good regulating effect to nitrogen removal of low C/N ratio wastewater. For COD and C/N ratio were150mg/L and2.5of sewage, the SPU-SBBR system showed better nitrogen removal efficiency(65.3%). Compared with polycaprolactone (PCL)-SBBR system (53.3%), thetotal nitrogen removal efficiency of SPU-SBBR system increased by12%.更多还原