【作者】 李艳平；

【导师】 李思敏；

【作者基本信息】 河北工程大学 ， 供热、供燃气、通风及空调工程， 2008， 硕士

【摘要】 为解决邯郸市西污水处理厂采用的改良型氧化沟系统存在的沟底积泥、脱氮率低等问题,本研究进行了氧化沟流体力学特性及运行优化控制的生产性试验研究。以氧化沟缺氧区为测试沟,进行曝气转碟[单速/双速（高、低速）]、水下推动器单独运行及两者联合运行时沟内流速测试,得出了其在各运行工况下的流速分布规律。直沟道流速存在着上中部高、下底部低的规律;各弯道流态非常复杂,其流速均存在着外侧高、内侧低及中部高、上下部低的规律。在测试沟内的直沟道和弯道处均发现存在不同程度的污泥沉积现象,基于此,根据沟内设备布置及前期试验情况,以水下推动器为分界点将测试沟分为三个区:RD04～RD11（东）、RD11～RS09（东）、RS09～RD04（西）,通过试验设计得出各区段的转碟和推动器的优化组合方式,并进行了验证试验,其结果表明,经调整后,直沟道、弯道的总体流态明显得到好转,虽仍存在部分积泥,分别为0.3～0.8m、0.4～1.2m（主要在第四弯道）,但这主要是因前期氧化沟一直靠经验调度而致使存留的部分死泥,一时还难以完全去除,这由其底部流速分别为0.14～0.27m/s、0.11～0.23m/s可看出。在此基础上,通过氧化沟系统的同步脱氮除磷试验研究及分析可知,工况调整前后系统对COD_Cr的去除变化不大且均较为稳定,分别为90.78%、91.04%,出水均能保持在70mg/L以下;对NH₄⁺-N、TN的去除率分别比调整前提高了11.57%、11.28%;调整后对应的出水TP浓度平均值为0.50mg/L,其去除率为93.93%,进行了良好的厌氧释磷、缺氧及好氧吸磷过程。通过正交试验及多指标试验结果的直观及方差分析得出,系统对COD_Cr、TN、TP去除的显著影响因素分别为:DO和MLSS、DO、MLSS和污泥回流比R;其最佳的运行参数:氧化沟缺、好氧区的DO分别为0.3～0.5 mg/L、2.0～2.5mg/L,MLSS=5000mg/L,R=65%。该系统的脱氮除磷效果很大程度上取决于DO值的控制,运行中保持缺、好氧区的DO浓度分别为0.3～0.7mg/L、2.0～3.2mg/L;要严格控制沟内的MLSS,其最佳范围为4600～5400mg/L;氧化沟工艺F/M的控制在0.06～0.13[kgBOD/（kgMLSS·d）],通过排泥将泥龄控制在16～20d。更多还原

【Abstract】 In order to solve sludge deposit in the bottom,low nitrogen removal efficiency of the modified oxidation ditch in Western Wastewater Treatment Plant in Handan city,the hydrodynamic characteristics and optimal operation and control in full-scale were studied in this paper.Considered anoxic zone of the oxidation ditch as the experimental ditch,the velocity were tested at the different conditions such as when only the aerating dish[single speed/double speed（with high or low velocity） or submersed flow driver and both of them running,results of velocity distribution figures in kinds of states were gained. There all existed high velocity in upper and intermediate,low velocity in below and bottom.And the flow pattern in crook ditches were very complex,there all existed high velocity outside and low inside,intermediate high,both upper and below low in kinds of crook ditch.And meanwhile there all existed sludge deposit in straight and crook ditches,on the basis of which,according to the devices arrangement and test results,the experimental ditch was divided into three parts by the submersed flow driver,as follows: RD04～RD11（east）,RD11～RS09（east）,RS09～RD04（west）,and then the optimal combination modes of aerating dishes and submersed flow driver were obtained by experiment design,and the feasibility was proved by experiment finally.The results revealed that the flow pattern in straight and crook ditches both had been improved obviously after the states adjusted,although there existed sediment 0.3～0.8m,0.4～1.2m （mainly existing in the forth crook ditch）,respectively,which made it exist dead sludge because of the previous scheduling by experience and not removed in short time,and it can be inferred that the below velocity were 0.14～0.27m/s,0.11～0.23m/s,respectively.On the basis of the above work,according to the experimental study and analysis of synchronous nitrogen and phosphorus removal by the oxidation ditch,it can be concluded that COD_Cr removal efficiency changed slightly before and after the states adjusted,90.70%,91.04%,respectively,COD_Cr concentration in effluent were always below 70mg/L.Compared to the states before adjusting,NH₄⁺-N and TN removal efficiency after adjusting were both increased by 11.57%,11.28%,respectively,and after adjusting average TP concentration in the effluent is 0.50mg/L,the TP removal efficiency was 93.93%,the processes of anaerobic phosphorus release,anoxic and aerobic phosphorus adsorption occurred.The optimal control parameters for COD_Cr,TN and TP removal were determined through orthogonal experiment of intuitive and variance analysis.The significant factors of COD_Cr and TN and TP removal by the modified oxidation ditch were DO and MLSS,DO,MLSS and R,respectively.The optimal operation parameters were determined as follows:DO concentration of anoxic and aerobic zone of 0.3～0.5 mg/L,2.0～2.5mg/L,respectively,MLSS concentration of 5000mg/L,sludge recycle flow rate of 65%.The nitrogen and phosphorus removal by the modified oxidation ditch depended on the control on DO concentration,DO concentration in anoxic and aerobic zone of oxidation ditch were 0.3～0.7,2.0～3.2mg/L,respectively.MLSS in the oxidation ditch should be controlled seriously,optimal MLSS concentration of 4600～5400mg/L,the control range of F/M was 0.06～0.13[kgBOD/（kgMLSS·d）],and sludge age was 16～20d through the discharge of residual waste.更多还原