炼油废水生化处理单元的数值研究与优化

发布时间：2018-02-22 06:07

本文关键词： 炼油废水传统活性污泥工艺两级A/O工艺模拟优化　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前对于炼油废水处理的提标方法主要是在生化单元后增加其他处理设备和工艺,增加了炼油废水处理的能耗及成本。本文以某炼油厂炼油废水第一、第二处理厂废水处理工艺设施的实际运行情况为例,应用Bio Win 5.0软件首先建立两级A(厌氧)/O(好氧)工艺生化单元的ASDM数学模型,对两级A/O工艺的生化处理单元进行模拟优化研究并进行现场实验验证,再建立传统活性污泥工艺模型,对传统活性污泥工艺生化单元进行模拟优化研究:1、通过实验分别对两级A/O工艺和传统活性污泥工艺进出水水质进行分析,实验检测模型所需水质常规组分和特殊组分。通过灼烧法测定各工艺曝气池中的污泥浓度(MLSS)用于评估工艺运行状况和建立模型。两级A/O工艺现场沉淀池存在跑泥现象,通过静态浓缩实验校正两级A/O工艺沉淀池模型。2、建立两级A/O工艺模型,模拟工艺实际运行状况并校准模型,并针对该工艺出水生化需氧量(COD)和总氮(TN)出水不达标等问题进行模拟优化。通过模拟优化发现,一级、二级O池溶解氧(DO)浓度对生化系统影响较小,维持在2mg/L即可,同时可节省曝气能耗;为保证工艺COD出水达标,一级A/O的MLSS维持在4000 mg/L左右,二级A/O的MLSS维持在2000 mg/L左右,同时采用分段进水,可提高TN处理效率,保证工艺TN出水达标。通过现场部分实验验证的模型优化结果,进一步验证了所建模型以及模型模拟优化方法的准确性。由于第一处理厂的两级A/O工艺模拟优化后仍存在无法达标的隐患,通过模拟对该工艺进行改造优化,将原工艺改造为水解池+一级A/O工艺,并将现场O池以及沉淀池并联使用,增加硝化液回流,且无需添加Na OH溶液。并通过模拟选择改造后工艺的最佳运行方案,改造后的工艺条件参数如下:好氧曝气池DO浓度保持在2mg/L,曝气池的MLSS应维持在3000~4000 mg/L,硝化液回流比为100%。改造后工艺较原工艺COD去除率提高2.5%,TN去除率提高19.6%,改造后优化效果明显。3、建立传统活性污泥工艺模型,模拟工艺实际运行状况并校准模型,并针对该工艺出水COD不稳定、易超标、出水TN无法达标等问题进行模拟优化。通过模拟优化发现,一级、二级O池DO浓度对系统影响较小,维持在2mg/L即可,同时可节省曝气能耗;为保证工艺COD出水达标,一级曝气池的MLSS维持在6000 mg/L左右,二级曝气池的MLSS维持在2000 mg/L左右;分段进水优化对TN去除效果影响较小,工艺优化无法使TN达标排放,需要通过模拟对该工艺进行改造优化。将原工艺改造为A/O工艺,将现场一级曝气池前半段改为厌氧段,将沉淀池并联使用;针对工艺出水TN无法有效去除的情况,增加硝化液回流,且无需添加Na OH溶液。通过模拟选择改造后工艺的最佳运行方案,改造后的工艺条件参数如下:好氧曝气池DO浓度保持在2mg/L,曝气池的MLSS应维持在3000~4000 mg/L,硝化液回流比为100%。改造后工艺较原工艺COD去除率提高3.12%,TN去除率提高36%,优化效果明显。
[Abstract]:The refinery wastewater treatment standard is the main method of increasing other processing equipment and technology in biochemical unit, increased energy consumption and cost of refinery wastewater treatment. In this paper a refinery refinery wastewater treatment facilities, second wastewater treatment plant operation situation as an example, using Bio Win 5 software is firstly established in two A (anaerobic) /O (aerobic) ASDM mathematical model of process of biochemical unit, biochemical treatment unit of two stage A/O process simulation and optimization research and field experiment, and then establish the conventional activated sludge process model, research on Simulation and optimization of conventional activated sludge biochemical unit: 1, through the experiment on two respectively. A/O process and conventional activated sludge process and water quality analysis, experimental testing model for conventional water quality and special compositions. Through the determination of the burning process in the aeration tank The sludge concentration (MLSS) was used to evaluate the operation condition and process model. The two stage A/O process on sedimentation tank sludge exist phenomenon, through the static concentration correction in two stage A/O process clarifier model.2, the establishment of two stage A/O process model, process simulation and actual operation condition and the calibration model, the effluent biochemical oxygen demand (COD) and total nitrogen (TN) of the water is not standard for simulation and optimization. It is found that, through the simulation and optimization of a grade, two grade O dissolved oxygen (DO) concentration had little effect on the biochemical system, can be maintained at 2mg/L, and can save the energy consumption of aeration; in order to ensure the process COD effluent standard, the level of A/O MLSS maintained at about 4000 mg/L, two A/O MLSS maintained at about 2000 mg/L, at the same time by step-feed, can improve the treatment efficiency of TN, ensure the process TN effluent standards. Through the optimization results of the model on experimental verification, further verified The model and simulation accuracy optimization method. Because there are still unable to reach the hidden dangers of simulation and optimization of two stage A/O process for the first treatment plant, through the simulation and optimization of the transformation process, the original process for the transformation of a hydrolysis pool + A/O process, and the scene to O pool and sedimentation tank used in parallel increase the nitrification liquid reflux without adding Na, OH solution. And the optimal operation scheme after the transformation process through the simulation, the following process parameters after the transformation of the aerobic aeration tank of DO concentration in 2mg/L, MLSS in aeration tank should be maintained at 3000~4000 mg/L, the nitrification liquid reflux ratio is 100%. after the transformation process is better than the original process for the removal rate of COD increased by 2.5%, the removal rate of TN increased by 19.6%, after the transformation of the optimization effect is obvious.3, a conventional activated sludge process model, process simulation and actual operation condition and the calibration model, the effluent COD is not stable, Easy to exceed the standard, the problem of effluent TN compliance can not simulated optimization. Found by simulation and optimization level, two level O pool DO concentration on the system has little effect, can be maintained at 2mg/L, and can save the energy consumption of aeration; in order to ensure the process COD effluent standard, an aeration tank MLSS is maintained at about 6000 mg/L, two aeration tank MLSS maintained at about 2000 mg/L; step-feed optimization have little influence on the removal of TN, process optimization can not make TN emission standards, through the simulation and optimization of the transformation process. The transformation process is A/O process, will be the scene of a stage aeration tank first half to anaerobic, the sedimentation tank according to the process used in parallel; the effluent TN can not effectively remove the situation, increase the nitrification liquid reflux, and there is no need to add Na OH solution. The optimal operation scheme of simulation selection after transformation process, the following conditions after the transformation parameters: Aerobic aeration tank DO When the concentration is kept at 2mg/L, the MLSS of the aeration tank should be maintained at 3000~4000 mg/L, and the reflux ratio of nitrifying liquid is 100%.. After transformation, the removal rate of COD is increased by 3.12% compared with the original process, and the removal rate of TN is increased by 36%, and the optimization effect is obvious.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X742

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