基于ASM2d模型对MBBR工艺的模拟与优化

发布时间：2018-03-16 02:08

本文选题：MBBR工艺　切入点：ASM2d模型　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：MBBR工艺通过向反应池中投加一定数量的载体,形成悬浮态的活性污泥和附着态的生物膜,而增加系统中硝化菌的浓度,强化脱氮效果。国家对城镇污水处理厂氮磷标准的提高,污水处理厂寻求提标改造的有效方式,使得MBBR工艺逐渐应用于污水厂的升级改造中。本文利用ASM2d模型对提标改造后的西安市第四污水处理厂一期MBBR工艺进行模拟,并对脱氮除磷系统进行优化设计,提出了 MBBR工艺优化控制方案,并通过数值模拟验证该优化方案的可行性。对MBBR工艺建模并进行初步稳态模拟,得到模拟结果与实际运行存在偏差。分析得出污水厂受进水水质和地域环境影响,微生物生化反应环境存在差异,参数取值范围很大,因此需要根据水处理厂实际情况对模型进水组分及参数进行实测。通过敏感性分析了解了不同参数取值误差对模型输出结果的影响大小,进而选择对状态变量影响较大的参数。敏感性较大的动力学参数有异养菌衰减速率常数bH、自养菌最大生长速率μAUT、异养菌基于基质的最大生长速率μH;敏感性较大的化学计量参数有异养菌产率系数YH和自养菌的产率系数YAUT;进水组分敏感度分析中,对出水COD影响最大的进水组分是S1,进水组分SNH4对氨氮和TN的影响较大,Xs对氨氮和TN的浓度也有影响,发酵产物SA、进水SpO4对出水的总磷影响较大。对进水组分和参数进行测定。采用间歇OUR法,测得YH、bH、μH、μA的值分别为0.684、0.415d-1、5.100d-1、0.708d-1 YA在活性污泥中比较稳定,采用YA的理论值0.24,bA目前还没有有效的方法测定,使用ASM2d模型推荐值0.15d-1;测定进水组分,得到SF、SA、S1、Xs、X1、XH 的平均值分别为 51.8mg/L、35.8mg/L、28.9mg/L、204mg/L、41 .0mg/L、32.4mg/L,占COD的比例分别为13%、9%、7%、52%、10%、8%。进水组分与其他地区比较存在差异,表明水质特征跟不同地区污水的性质、来源等因素有较大关系。对模型进行校准,并用校准后的模型分析系统曝气(DO)、混合液回流比(R)、污泥回流比(r)、填料填充率(PR)、温度因素对工艺运行的影响。提出了优化控制方案为,高温季节控制DO在2.0～2.5mg/L范围内、R在1500%～200%范围内、r为600%～70%、PR 为 20%;低温季节可控制 DO 为 2.5～30mg/L、R 为 150%～200%、r为 70%～80%、PR为25%。若运行过程中脱氮效果不理想,首先考虑适当增大r,其次增大DO;若运行过程中除磷效果不理想,优先调控r,将r控制在合理的范围,其次,合理的控制DO。在同时考虑脱氮与除磷时,综合调控r和DO两个参数,再考虑调控其他参数。
[Abstract]:By adding a certain number of carriers to the reactor, MBBR process forms suspended activated sludge and attached biofilm, while increasing the concentration of nitrifying bacteria in the system and strengthening the denitrification effect. The MBBR process has been gradually applied to the upgrading of wastewater treatment plant due to the effective way of the improvement of the wastewater treatment plant. This paper simulates the first stage MBBR process of Xi'an 4th sewage treatment plant after upgrading the standard by using the ASM2d model. The optimal design of denitrification and phosphorus removal system was carried out, and the optimal control scheme of MBBR process was put forward, and the feasibility of the optimization scheme was verified by numerical simulation. The MBBR process was modeled and the initial steady state simulation was carried out. It is concluded that the wastewater treatment plant is affected by the influent water quality and regional environment, and the environment of microbial biochemical reaction is different, and the range of parameters is very large. Therefore, according to the actual situation of the water treatment plant, the components and parameters of the model influent are measured, and the influence of the error of different parameters on the output of the model is analyzed by sensitivity analysis. The most sensitive kinetic parameters are heterotrophic decay rate constant bH, autotrophic bacteria maximum growth rate 渭 auto, heterotrophic bacteria based maximum growth rate 渭 H; The stoichiometric parameters include the yield coefficient of heterotrophic bacteria YH and the yield coefficient of autotrophic bacteria YAUT. in the sensitivity analysis of influent components, The influent component that has the greatest influence on effluent COD is S1, and the influent component SNH4 has great influence on ammonia nitrogen and TN. Xs also has influence on the concentration of ammonia nitrogen and TN. The influent SpO4 had a great effect on the total phosphorus of the effluent. By using intermittent OUR method, the values of YH, 渭 H and 渭 A were 0.684 ~ 0.415d ~ (-1) ~ 5.100d ~ (-1) ~ 0.708d ~ (-1) YA, respectively, which were stable in the activated sludge. At present, there is no effective method to determine the theoretical value of YA 0.24 mgL, and the recommended value of 0.15 d ~ (-1) using ASM2d model is 0.15 d ~ (-1). By determining the influent component, the average value of XS-1 X1XH is 51.8 mg / L ~ 35.8 mg / L ~ (28. 9) mg / L ~ (28. 9) mg / L ~ (41) mg / L ~ (41 路0) mg 路L ~ (-1) = 32. 4 mg / L, respectively, and the proportion of the influent water to COD is 13 ~ (79)% 722 ~ (52) 1010 ~ 80.Compared with other regions, there is a difference between the influent group and other regions. The results show that the characteristics of water quality are closely related to the nature and source of sewage in different areas. With the calibrated model analysis system, the effects of aeration, mixture reflux ratio, sludge reflux ratio, filler filling ratio and temperature on the operation of the process are put forward. In the high temperature season, do is controlled in the range of 2.0 ~ 2.5 mg / L and R is in the range of 1 500 ~ 200%. The R is 600 and 70%, and the PR is 20. In the low temperature season, it can be controlled that the do is 2.5? 30 mg / L? r? 150??? If the phosphorus removal effect is not ideal, the priority is to control r in a reasonable range, and the second is to control DO.When nitrogen and phosphorus removal are considered at the same time, two parameters, r and do, are comprehensively regulated. Consider regulating other parameters.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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