UCT复合MBR处理低碳源污水工艺参数优化及模型应用研究

发布时间：2018-03-07 06:03

本文选题：低碳源　切入点：UCT复合MBR　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：传统工艺在处理低碳源的污水时,经常会出现出水氮、磷含量超标的情况,其根本原因是碳源不足,反硝化细菌难以获得足够能量进行反硝化,而聚磷菌难以获得足够能量进行好氧吸磷,所以脱氮除磷效率低。为解决上述问题,研究采用UCT复合MBR工艺,在不改变DO和MLSS的基础上,通过改变硝化液回流比、水力停留时间、分段进水及在缺氧区投加填料等方式寻找最优处理工况。分析在不同工况下不同污染物的去除效果及滤膜的作用,同时分析填料生物相及投加填料后对污染物的去除影响及其机理。此外,在ASM1和ASM2D模型基础上分别建立并验证了厌氧区有机物降解模型,缺氧区反硝化除磷模型和好氧区硝化模型。得到了如下结论。(1)工艺对COD的去除效果良好,所有工况出水平均值均优于《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。运行期间TN去除率平均为83.41%,说明工艺能够在较低的C源时取得较好的处理效果,并且装置缺氧段出现了短程硝化反硝化。投加填料能明显提高亚硝态氮的积累。工艺对TP去除效果良好,工况一、二和三达到城镇污水处理厂污染物排放标准一级B,工况四和五可以达到一级A标准。装置在不同工况出现了不同程度的反硝化除磷效果,其中工况五的反硝化除磷率达到了39%,说明投加填料对反硝化除磷有较好的强化效果。最优工况为工况五,工况参数为水力停留时间8h,硝化液回流比150%,采用分段进水方式并在缺氧区投加填料。(2)平板膜组件对COD、TN、NH3-N、TP的去除贡献率分别为9.63%、7.01%、0.86%、0.82%,说明膜对不同污染物有不同的截留效果。圆形平板膜污染为三个阶段,第一阶段为滤饼层污染,第二阶段形成动态膜,抑制通量进一步减小,第三阶段膜孔堵塞,造成不可逆污染。在缺氧池投加填料后,装置的整体处理效果和稳定性得到提高。(3)在ASM1模型、ASM2D模型基础上,建立了针对厌氧区、缺氧区和好氧区的有机物降解、缺氧区反硝化除磷及好氧区硝化三个模型。①厌氧区出水COD浓度稳态方程的模型预测值最小误差率为0.79%,最大误差率4.15%;②缺氧区出水总磷浓度浓度稳态方程的模型预测值最小误差率为1.44%,最大误差率为11.33%;③好氧段出水氨氮浓度的稳态方程的模型预测值最小误差率为3.63%,最大误差率为15.23%。
[Abstract]:In the treatment of low carbon source sewage, the effluent nitrogen and phosphorus content in the traditional process often appear the situation that the content of nitrogen and phosphorus exceeds the standard. The fundamental reason is that the carbon source is insufficient, so denitrifying bacteria can not get enough energy to denitrification. In order to solve the above problem, the UCT compound MBR process was used to solve the problem, and on the basis of not changing do and MLSS, the ratio of nitrifying solution reflux was changed, in order to solve the above problems, the phosphorus accumulating bacteria could not get enough energy to absorb phosphorus by aerobic absorption, so the nitrogen and phosphorus removal efficiency was low. Hydraulic retention time (HRT), subsection inlet water and adding packing in anoxic zone were used to find the optimal treatment conditions. The removal effect of different pollutants and the effect of filter membrane were analyzed under different working conditions. At the same time, the effects of biophase on the removal of pollutants and its mechanism were analyzed. In addition, the degradation models of organic matter in anaerobic zone were established and verified on the basis of ASM1 and ASM2D models, respectively. The model of denitrification and phosphorus removal in anoxic zone and the model of nitrification in aerobic zone were obtained. The average effluent of all working conditions is better than the first class A standard of "pollutant discharge standard of municipal wastewater treatment plant" (GB18918-2002). The average TN removal rate during operation is 83.41, which shows that the process can obtain better treatment effect at lower C source. And the short cut nitrification and denitrification appeared in the anoxic section of the plant. The addition of filler could obviously increase the accumulation of nitrite nitrogen. The process had a good removal effect on TP. Two and three reached the first class B of the municipal wastewater treatment plant pollutant discharge standard, and four and five conditions could reach the first A standard. The device had different degrees of denitrifying phosphorus removal effect in different working conditions. The denitrifying phosphorus removal rate of working condition 5 has reached 39, which shows that adding filler has a better enhancement effect on denitrifying phosphorus removal. The operating condition parameters are HRT 8 h, nitrifying liquid reflux ratio 150, the removal contribution rate of COD TNN NH 3-NN TP to COD TNN NH 3-NN TTP removal by means of subsection influent and adding packing. 2 in anoxic zone is 9. 63% 7.01% 0.86% 0.82% respectively, which shows that the membrane has different retention efficiency to different pollutants. The circular flat membrane fouling is divided into three stages. The first stage is filter cake layer pollution, the second stage forms dynamic membrane, the inhibition flux decreases further, the third stage membrane hole is blocked, causing irreversible pollution. The overall treatment efficiency and stability of the plant were improved. (3) based on the ASM1 model and ASM2D model, the degradation of organic matter in anaerobic, anoxic and aerobic regions was established. Three models of denitrifying phosphorus removal in anoxic zone and nitrification in aerobic area..1 the model prediction of COD steady state equation of effluent concentration in anaerobic zone is predicted by the model with minimum error rate of 0.79 and maximum error rate of 4.15% with respect to the steady-state equation of effluent total phosphorus concentration in anoxic zone. The minimum error rate of the model is 1.44 and the maximum error rate is 11.33 ~ 3 aerobic effluent ammonia nitrogen concentration. The minimum error rate is 3.63 and the maximum error rate is 15.2323.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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