城镇污水厂二级生化出水臭氧深度处理技术研究

发布时间：2019-06-04 22:17

【摘要】：为解决某城镇污水处理厂二沉池出水COD及氨氮提标问题,提出经济、合理的提标改造方案,对现有污水厂2015年四季度进出水口COD、氨氮、色度等常规和非常规指标进行跟踪监测和水质分析,并对存在的问题进行了分析与总结。提出了“O3氧化+曝气生物滤池”的深度处理工艺,通过正交实验及单因素实验对单独臭氧氧化和臭氧/活性炭氧化两种氧化法进行了条件优化研究,从经济及技术效果角度筛选出臭氧/活性炭氧化法更适合作为后续生物处理的预处理方法。筛选出活性炭作为曝气生物滤池的内充填料,并将臭氧/活性炭氧化与活性炭曝气生物滤池串联运行,分别考察其在连续流条件下对二沉池出水水质中COD、总氮及色度的去除效果,得出的主要结论如下:1)通过全年数据监测及水质分析,现有污水处理厂主要存在的问题是进水水质复杂,进水成分包含了印染、化工企业的城镇生活污水废水,水质波动较大,规律性较差,GC-MS显示二沉池出水剩余COD主要属于苯环类物质,且难生物降解;出水氨氮浓度为11 mg/L左右,且存在一定色度,应采取措施加以消减。2)通过静态条件优化实验得出,臭氧/活性炭氧化法比单独臭氧氧化法对二沉池出水COD去除效率高17%,可生化性提高2.78%,且减少臭氧通量31.7%,具有更高的环境及经济效益,筛选出臭氧/活性炭氧化法作为后续生物处理的预处理方法。臭氧/活性炭氧化法条件优化实验表明,在进水COD为105 mg/L,NH4+-N为11.8mg/L,臭氧接触反应时间30 min,pH为9,臭氧通量为12.50 mg/L,活性炭投加体积比为2/3时,二沉池出水COD去除率为45%左右,氨氮去除率为44.9%。3)筛选出曝气生物滤池的最佳填料为活性炭填料,在相同进水条件下,活性炭比陶粒曝气生物滤池COD去除率高8.58%。在连续运行条件下,臭氧/活性炭氧化反应器在进水COD为89.7~109.8 mg/L时,出水COD为68.1 mg/L,COD去除率为31%。活性炭曝气生物滤池在水力停留时间为2 h时,出水COD均小于50 mg/L,COD去除率为21.4~54.7%。在进水氨氮浓度为11.6 mg/L时,色度为450倍时,经串联工艺处理后,出水总氮为3.9 mg/L,出水色度为5倍,出水水质满足《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准(COD50 mg/L)。“臭氧/活性炭+曝气生物滤池”可作为该污水处理厂COD及氨氮提标排放的升级改造方案。
[Abstract]:In order to solve the problem of COD and ammonia nitrogen raising in the effluent of secondary sedimentation tank of a urban sewage treatment plant, an economical and reasonable scheme of bid raising and transformation was put forward, and the COD, ammonia nitrogen at the inlet and outlet of the existing sewage treatment plant in the fourth quarter of 2015 was put forward. The conventional and unconventional indexes such as chromaticity are followed up and analyzed, and the existing problems are analyzed and summarized. The advanced treatment process of "biological aerated filter for O3 oxidation" was put forward. The conditions of ozone oxidation alone and ozone / activated carbon oxidation were optimized by orthogonal experiment and single factor experiment. From the point of view of economic and technical effects, ozone / activated carbon oxidation is more suitable as a pretreatment method for subsequent biological treatment. Activated carbon was selected as the internal filling material of biological aerated filter, and ozone / activated carbon oxidation was carried out in series with activated carbon biological aerated filter. The COD, in the effluent quality of secondary sedimentation tank was investigated under the condition of continuous flow. The main conclusions of total nitrogen and chromaticity removal are as follows: 1) through annual data monitoring and water quality analysis, the main problems in the existing sewage treatment plants are that the influent water quality is complex, and the influent composition includes printing and dyeing. The water quality of municipal domestic sewage wastewater in chemical enterprises fluctuates greatly and the regularity is poor. GC-MS shows that the remaining COD in the effluent of the secondary sedimentation tank mainly belongs to benzene ring substances and is difficult to biodegrade. The concentration of ammonia nitrogen in the effluent is about 11 mg/L and there is a certain chromaticity, so measures should be taken to reduce it. 2) through the static condition optimization experiment, it is obtained that, Compared with ozone oxidation alone, ozone / activated carbon oxidation has 17% higher COD removal efficiency, 2.78% more biodegradability and 31.7% lower ozone flux, which has higher environmental and economic benefits. Ozone / activated carbon oxidation was selected as a pretreatment method for subsequent biological treatment. The optimization experiment of ozone / activated carbon oxidation conditions shows that when the influent COD is 105 mg/L,NH4-N is 11.8 mg 路L, the ozone contact reaction time is 9 min,pH and the ozone flux is 12.50 mg/L,. When the volume ratio of activated carbon is 2 / 3, the removal rate of COD and ammonia nitrogen in the effluent of the secondary sedimentation tank is about 45% and 44.9% respectively. The COD removal rate of activated carbon was 8.58% higher than that of ceramsite biological aerated filter. Under the condition of continuous operation, when the influent COD of ozone / activated carbon oxidation reactor is 89.7 mg/L, the effluent COD removal rate is 68.1 mg/L,COD and 31%. When the HRT of activated carbon biological aerated filter is 2 h, the removal rate of COD in effluent is 21.4 mg/L,COD 54.7%. When the influent ammonia nitrogen concentration is 11.6 mg/L and the chromaticity is 450 times, the total nitrogen content of the effluent is 5 times when the effluent nitrogen concentration is 11.6 mg/L and 450 times, and the effluent total nitrogen is 5 times when the influent ammonia nitrogen concentration is 11.6 mg/L, and the chromaticity is 450 times. The effluent quality meets the Pollutant discharge Standard (GB18918-2002) Grade A Standard (COD50 mg/L) of Urban sewage treatment Plant. Ozone / activated carbon biological aerated filter (BAF) can be used as an upgrade scheme for COD and ammonia nitrogen discharge in the sewage treatment plant.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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