污水处理厂氧化沟工艺脱氮除磷提升改进研究

发布时间：2018-04-23 15:06

本文选题：脱氮 + 除磷　；参考：《西南科技大学》2017年硕士论文

【摘要】：针对我国目前的水环境质量现状,国家进一步提高了城镇污水处理厂出水水质要求。目前出水TN、TP等污染物不达标的城镇污水处理厂,必须进行技术升级改进。本研究以西南科技大学污水处理厂氧化沟为研究对象,通过对2012-2014年西南科技大学污水处理厂进出水水质数据分析,探明该污水处理厂的运行效果及存在的问题,从而探讨可行的工艺参数优化措施。通过静态研究,考察了增加曝气时间、减少沉淀时间、调整HRT对氧化沟出水水质的影响,并在此基础上,提出氧化沟的两种改进运行方式。采用自制的氧化沟小试装置,对比了两种改进运行方式对生活污水的处理效果,优化了HRT、排泥方式等运行参数。并通过鸟粪石沉淀法回收污泥浓缩上清液中的氮磷,初探了其上清液回流对污水处理厂进水氮磷负荷的影响。得到的研究结果如下:通过对西南科技大学污水处理厂进出水水质数据分析表明:该污水处理厂氧化沟工艺进水BOD5、TN、NH_3~-N和TP浓度难以同时满足设计进水水质指标要求,处理后出水中TN、NH_3~-N和TP浓度难以稳定达到《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级A标准要求,需要进行提标改进。静态试验研究表明:在原氧化沟A池(边沟)曝气90min后,增加曝气时间可以降低污水中TN、NH_3~-N、TP的浓度,在综合考虑对各水质指标的去除率及能耗的情况下,增加曝气20min,即曝气110min时,对污水中污染物的总体去除效果较好;适当缩短沉淀时间,能够降低污水中TP浓度,A/C池(边沟)沉淀时间由原来的5h缩短至3h时,对污水中污染物的总体去除效果较好;HRT由18.2h缩短至16h时,对污水中污染物的总体去除效果较好。并由此提出氧化沟的两种改进运行方式。动态试验研究表明:小试装置启动稳定后,当HRT为18.2h时,改进式运行方式?对CODCr、TN、NH_3~-N、TP的去除效果优于改进式运行方式?;在HRT为16h时,运行方式?、?对CODCr、TN、NH_3~-N、TP去除效果最佳;在排泥量相同的条件下,A/C池(边沟)与B池(中沟)同时排泥的方式对污水中TP的去除效果优于仅从B池(中沟)排泥的方式。该氧化沟小试装置在优化工艺参数条件下的运行结果表明:其出水CODCr浓度范围为26mg/L-40mg/L、出水TN浓度范围为6.2mg/L-12.7mg/L、出水NH_3~-N浓度范围为2.5mg/L-4.2mg/L,即出水CODCr、TN、NH_3~-N均能达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准;但出水TP浓度范围为0.33mg/L-0.80mg/L,即出水TP浓度难以稳定达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。鸟粪石沉淀研究表明:鸟粪石形成的适宜反应条件是溶液初始pH为9.5、反应时间为10min、温度为10-30℃。在此反应条件下,污泥浓缩池上清液中的PO_4~(3-)-P和NH_4~+-N含量(均值)分别由反应前的0.46mmol/L和2.0mmol/L降至反应后的0.15mmol/L和1.74mmol/L,对污泥浓缩池上清液中PO_4~(3-)-P和NH_4~+-N的平均去除浓度分别为0.31mmol/L(9.61mg/L)和0.26mmol/L(3.64mg/L),对污泥浓缩池上清液中PO_4~(3-)-P和NH_4~+-N回收率分别达到68%和13%。该沉淀物中鸟粪石纯度为44%。该污水处理厂污泥浓缩池上清液产量为100m~3/d,鸟粪石沉淀反应可从浓缩池上清液去除PO_4~(3-)-P约为961g/d,NH_4~+-N约为364g/d。结合2014年度该污水处理厂PO_4~(3-)-P(以TP计)和NH_4~+-N(以NH_3~-N计)进水平均浓度数据(分别为5.3mg/L和46mg/L),通过鸟粪石沉淀反应可降低污水处理厂进水TP浓度约0.2mg/L、进水NH_3~-N浓度约0.08mg/L。通过鸟粪石沉淀反应在回收氮磷资源的同时可降低污泥浓缩池上清液回流对氧化沟处理单元带来的氮磷负荷。
[Abstract]:In view of the current quality of water environment in China, the country has further improved the water quality requirements of the urban sewage treatment plant. At present, the urban sewage treatment plant, such as TN, TP and other pollutants, must be upgraded. This study takes the oxy ditch of the sewage treatment plant of Southwest University of Science and Technology as the research object, through 2012-2014 years southwest. The water quality data of the sewage treatment plant of the University of science and technology is analyzed, the operation effect and the existing problems of the sewage treatment plant are explored, and the feasible process parameter optimization measures are discussed. Through the static study, the effect of increasing the aeration time, reducing the precipitation time and adjusting the water quality of the effluent of the oxidation ditch by HRT is adjusted, and on this basis, the oxidation is put forward. Two improved operation modes of the ditch were used. Using the self-made oxidation ditch pilot device, the treatment effect of two improved operating modes on domestic sewage was compared, the operating parameters of HRT and sludge arrangement were optimized. The nitrogen and phosphorus in the sludge concentrated supernatant were recovered by the method of bird droppstone precipitation, and the influent nitrogen and phosphorus of the wastewater treatment plant by the reflux of the supernatant was explored. The results of the study are as follows: through the analysis of the water quality data of the sewage treatment plant of Southwest University of Science and Technology, it is shown that the oxidation ditch process of the wastewater treatment plant is BOD5, TN, NH_3~-N and TP are difficult to meet the requirements of the design of water quality at the same time. The concentration of TN, NH_3~-N and TP in the effluent after treatment is difficult to reach "town". The first grade A standard of pollutant discharge standard of sewage treatment plant (GB18918-2002) needs to be improved. Static test research shows that the increase of aeration time can reduce the concentration of TN, NH_3~-N and TP in sewage after A pool (side ditch) aeration of the original oxidation ditch, and increase the concentration of TN, NH_3~-N and TP in the sewage, and increase the removal rate and energy consumption of each water quality index. The overall removal effect of pollutants in sewage is better with aeration 20min, that is, aeration 110min, and the total removal efficiency of pollutants in sewage is better. It can reduce the concentration of TP in sewage properly. When the precipitation time of A/C pool (edge ditch) is shortened from the original 5h to 3h, the overall removal effect of pollutants in sewage is better; when HRT is shortened from 18.2h to 16h, the total pollutant in sewage is reduced to the total pollutant in sewage. Two improved operation modes of oxidation ditch are put forward. Dynamic test study shows that when the pilot device is stable, when HRT is 18.2h, the improved operation mode is better than the improved operation mode for CODCr, TN, NH_3~-N, TP. When HRT is 16h, operation mode is the most effective for CODCr, TN, NH_3~-N, TP. Under the same sludge discharge condition, the removal effect of A/C pool (edge ditch) and B pool (middle ditch) at the same time is better than that of only B pool (middle ditch). The operation results of the oxidation ditch pilot device under the optimized process parameters show that the CODCr concentration range of the effluent is 26mg/L-40mg/L, and the TN concentration range of the effluent is 6.2. Mg/L-12.7mg/L, the concentration range of the effluent NH_3~-N is 2.5mg/L-4.2mg/L, that is, the effluent CODCr, TN, NH_3~-N can reach the first grade A standard of the pollutant discharge standard of the municipal wastewater treatment plant (GB18918-2002), but the effluent TP concentration range is 0.33mg/L-0.80mg/L, that is, the TP concentration of the effluent is difficult to reach the pollutant discharge standard of the municipal wastewater treatment plant (GB18918-). 2002) first class A standard. The study of bird Dropstone precipitation shows that the appropriate reaction conditions for the formation of bird Dropstone are that the initial pH of the solution is 9.5, the reaction time is 10min, and the temperature is 10-30. In this reaction condition, the content of PO_4~ (3-) -P and NH_4~+-N in the sludge concentration pool is reduced from 0.46mmol/L and 2.0mmol/L before the reaction to 0.15 after the reaction. Mmol/L and 1.74mmol/L, the average removal concentration of PO_4~ (3-) -P and NH_4~+-N in the sludge concentration pool was 0.31mmol/L (9.61mg/L) and 0.26mmol/L (3.64mg/L) respectively. The PO_4~ (3-) and recoveries in the liquid sludge concentration pool were 68%, respectively, and the purity of the sludge concentration in the wastewater treatment plant The yield of the supernatant is 100m~3/d, and the precipitation of bird droppings can remove PO_4~ (3-) -P about 961g/d from the clear solution of the concentrated pool, and NH_4~+-N is about 364g/d. combined with PO_4~ (3-) -P (TP meter) and NH_4~+-N (respectively) in the sewage treatment plant in 2014. The concentration of the influent TP in the treatment plant is about 0.2mg/L, and the concentration of the influent NH_3~-N is about 0.08mg/L. through the precipitation of bird droppings in the recovery of nitrogen and phosphorus resources, while reducing the nitrogen and phosphorus load caused by the reflux of the sludge concentration pool on the oxidation ditch treatment unit.

【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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