【作者】 贺颖；

【导师】 吉芳英；

【作者基本信息】 重庆大学 ， 环境工程， 2011， 硕士

【摘要】 论文在全面综述生物除磷脱氮理论和技术的基础上,分析课题组前期研究得出的侧流除磷反硝化除磷系统A2N-P-SBR具有优异除磷脱氮效果和低污泥产率、长污泥龄等特性,认为在侧流除磷反硝化除磷系中,由于除磷方法的改变导致污泥龄的控制将有别于传统生物除磷系统。为此,论文采用调控污泥龄的手段系统研究了污泥龄对反硝化聚磷系统的影响,进一步利用微量热仪测定了不同泥龄系统生物除磷周期的能量变化趋势。在对碳源利用情况分析的基础上,从能量和物质转变角度跟踪测量生物除磷脱氮系统碳的转化、循环过程,揭示了侧流除磷反硝化除磷系统低需氧、低污泥产率和良好脱氮除磷效率的内在原因。研究结果表明:①侧流除磷反硝化除磷系统A2N-P-SBR随着污泥龄SRT增大出水COD浓度降低。出水总磷浓度无差异,去除率在93%以上,生物除磷脱氮系统污泥龄的取值可以单纯由生物脱氮系统决定。出水氨氮、总氮浓度先迅速降低后趋于平稳。随SRT越长除磷脱氮SBR中滞留的微生物越多,平均污泥浓度越高。且污泥容积指数SVI增加,沉降性能增强。污泥含磷量越大。当SRT为32d和64d时,A2N-P-SBR中除磷脱氮SBR厌氧段释磷效果和缺氧段反硝化效果最好。当SRT小于32d,反硝化除磷反应器COD吸收量随泥龄增大而增大;当SRT大于32d,COD吸收量随泥龄增大而减小。综合各污染物出水浓度、除磷脱氮SBR各个阶段脱氮除磷速率和污泥沉降性能,得出污泥龄大于32d处理效果好。污泥龄为32d时处理效果最好;污泥龄为160d时排泥量最小,污染物去除效果也较好。②除磷脱氮SBR厌氧段释磷后先进行长时间的缺氧再好氧,既可以为DPB提供良好生存环境,也能大大促进好氧聚磷效果。缺氧段的吸磷和脱氮过程均能在50min内完成,说明完全可以缩短缺氧段的反应时间,但时间缩短后是否会影响DPB的活性和优势菌的地位需要进一步试验。缩短反应周期后,硝化SBR反应时间为5h时,反应器最佳溶解氧可控制在1.0mg/L~1.5mg/L,此时氨氮能被彻底氧化同时耗能少,微生物也可以避免进入内源呼吸期状态。③随SRT越长除磷脱氮SBR污泥产率系数Ys越低。当污泥龄大于32d后反硝化除磷系统的Ys在0.2以下,远远低于传统生物除磷脱氮系统的0.4~0.5,说明侧流除磷反硝化除磷系统的具有低污泥产率的特点。④乙酸作为碳源时反硝化除磷系统摩尔产热量是传统生物除磷方式的两倍。传统生物除磷方式中,好氧阶段放热量远远大于厌氧阶段,通过对总放热量的分析计算得到传统生物除磷系统自身衰减系数Kd为0.02。反硝化除磷系统中随污泥龄SRT越长,厌氧段达到放热峰值的时间越短。同时SRT与放热值K(ΔGR)之间存在良好的线性关系,SRT越长K(ΔGR)越高,用于细胞物质合成的能量越少微生物增殖缓慢,污泥产率系数越低。当SRT为常见的20d时,放热量为104.59kJ/mol e-。放热量和表观污泥产率系数的变化非常接近,两者有密切关系。反硝化除磷系统总放热量略大于理论放热量,说明缺氧段微生物将厌氧段贮存的能量利用完全后,继续利用其他碳源如死亡的细胞或者内碳源继续进行反硝化而放热,氧化还原反应很彻底,系统已无剩余的热量为细菌繁殖所用,这是反硝化除磷系统污泥产率低的根本原因。课题研究成果不仅揭示了污泥龄对侧流除磷反硝化除磷系统的影响方式,同时可以为反硝化除磷技术的应用提供生物能学及热力学参考。课题研究得到国家自然科学基金项目(50278101)与国家水体污染控制与治理重大科技专项(2009ZX07315)的资助。更多还原

【Abstract】 Based on comprehensive reviewing the theoretical and technical of biological nitrogen and phosphorus removal, analyzing the characteristics such as good nitrogen and phosphorus removal effect, low sludge yields and long sludge age of the denitrifying phosphorus removal system with side-stream phosphorus removal (A2N-P-SBR) researched previously, the thesis considers that the sludge age control of the denitrifying phosphorus removal system with side-stream phosphorus removal is different from the traditional biological phosphorus removal system because of the change of phosphorus removal method. So the effect of SRT on denitrifying phosphorus removal system is studied by using method of sludge age control. The variation trend of energy of each biological phosphorus removal period of the system with different sludge age is measured by microcalorimetric. From the perspective of energy and material change, conversion and cyclic process of carbon of the biological nitrogen and phosphorus removal system is tracking measured. Based on analyzing the carbon sources utilization, inner reasons of the low oxygen demand, sludge yield and good nitrogen and phosphorus removal efficiency of the denitrifying phosphorus removal system with side-stream phosphorus removal are revealed. The experiment results show that:①The longer the sludge age is, the lower the effluent COD concentration is in the denitrifying phosphorus removal system with side-stream phosphorus removal (A2N-P-SBR). There is a little changes of the effluent total phosphorus concentration of the system with different SRT. The removal rate of the TN is all above 93%, and the sludge age values of biological phosphorus and nitrogen removal system can be determined merely by biological nitrogen removal system. Effluent concentration of ammonia nitrogen and total nitrogen decrease rapidly at first and then change to be steady. With the SRT increase, microorganisms stranded in the denitrifying phosphorus removal SBR increase, the average sludge concentration is higher. And the sludge volume index (SVI) increase, settling property enhance, p content in sludge increase. When the SRT is 32d and 64d, effect of anaerobic phosphorus release and anoxic denitrification of SBR in A2N-P-SBR is best. When the SRT is less than 32d, COD uptake increases with sludge age increases of SBR. When the SRT is greater than 32d, COD absorption decreases with the sludge age increases. The effluent concentration of each pollutant, nitrogen and phosphorus removal rate at all stages of SBR and the sludge settling properties are comprehensively analyzed. They results show that there is a good treatment effects when SRT is greater than 32d. The treatment effect is best when the Sludge age is 32d; the emission amount of sludge is least and pollutant removal effect is good when the sludge age is 160d.②After the phosphorus removal of anaerobic stages in nitrogen and phosphorus removal SBR, if there is a long anoxic stage before aerobic stage, the system can provide a good living environment for DPB and contribute much to the effect of aerobic phosphorus uptake. Phosphorus uptake and nitrogen release of anoxic stage can be completed in 50min. It shows that the reaction time of anoxic stage definitely can be shortened. Whether the short anoxic stage affects the activity and the dominant position of DPB still needs further experiment. When the reaction time of nitrifying SBR is 5h after the reaction cycle is Shortened, the optimum dissolved oxygen in the reactor can be controlled between 1.0mg / L ~ 1.5mg / L. Under the optimum conditions, ammonia can be completely oxidized and consume less energy, and can prevent microbes from entering into endogenous phase.③The longer the SRT is, the lower the sludge yield coefficient (Ys) is in the nitrogen and phosphorus removal SBR. When the sludge age is greater than 32d, the Ys of denitrifying phosphorus removal system is under 0.2. It is far below the value (0.4 to 0.5) of traditional biological nutrient removal system. The result indicates that denitrifying phosphorus removal system with side-stream phosphorus removal has a low sludge removal yield.④When the acetic acid is as a carbon source in denitrifying phosphorus removal system, the molar heat production is twice than the heat produced from traditional biological phosphorus removal system. The heat released from the aerobic phase is far greater than the anaerobic phase in traditional biological phosphorus removal system. The analysis of the total heat release shows that attenuation coefficient (Kd) of the traditional biological phosphorus removal system is 0.02. The time needed for the anaerobic exothermic peak is shortened when the SRT gets longer in denitrifying phosphorus removal system. There is a good linear relationship between SRT and the heat value (K(ΔGR)).The longer the sludge age the higher the K(ΔGR). Less energy is used for the synthesis of cellular material with sludge age. Cell proliferation is restrained, and sludge yield coefficient is low. When the SRT is a common 20d, the heat release is 104.59kJ/mol e-. The change of heat release and the apparent sludge yield coefficient is quite similar, and they are closely related. The practical heat release is greater than the theoretical heat release in denitrifying phosphorus removal system. The result indicates that when the energy stored in the anaerobic stage is utilized completely in the anoxic stage, the microorganism will continue to use other carbon sources such as dead cells or the carbon source to denitrify and release heat. As a consequence the redox reaction is finished completely, there is no more energy used for bacterial reproduction in the system. That is the basic reason of low sludge yield of the denitrifying phosphorus removal system.The results of the study reveal the influence mode of different sludge age on the denitrifying phosphorus removal system with side-stream phosphorus removal, and provide the reference of bioenergetics and thermodynamics for the denitrifying phosphorus removal technology.This research was sponsored by the National Natural Science Foundation of China (50278101) and Grand science and technology special project in National Water Pollution Control and Management of China(2009ZX07315).更多还原