【作者】 庞博；

【导师】 彭永臻；

【作者基本信息】 哈尔滨工业大学 ， 环境工程（专业学位）， 2019， 硕士

【摘要】 寒冷地区城市污水具有脱氮难等问题,传统生物处理工艺很难长期稳定运行。同步硝化反硝化（SND）在同一反应器内同时产生硝化、反硝化和除碳反应,充分证明了可以在同一环境下发生硝化反硝化的脱氮假设,经济环保。但在温度较低的环境下,微生物活性大幅下滑,使系统出水不够稳定。利用生物膜填料,能够有效增强反应系统对寒冷地区生活污水的处理能力。本研究为实现低温条件下对生活污水的达标处理,将聚氨酯生物膜填料投加到SBR反应器,构建聚氨酯生物膜填料与活性污泥共存的复合系统。通过分析挂膜成熟的聚氨酯生物膜填料及聚乙烯生物膜填料对配水的处理效果,确定生物膜填料-活性污泥复合工艺（SBBR）最终所用填料。聚氨酯生物膜填料与聚乙烯生物膜填料相比,比表面积更大,生物膜更易在其上附着成长,进入反应器后能快速为生物膜所附着。试验表明,投加聚氨酯生物膜填料的污水处理系统出水NH₄⁺-N、COD明显高于投加聚乙烯生物膜填料的污水处理系统,平均去除率分别高14.69%、8.2%。说明聚氨酯生物膜填料孔隙微小,能够作为很好的屏障庇护已附着生长的菌体,确保菌体在优良环境下成长。在置于冷柜中的SBR反应器中建立好氧活性污泥与聚氨酯生物膜填料共存的填料强化SND反应器处理城市污水。经110天培养,系统出水NH₄⁺-N浓度维持在3⁵ mg/L,总氮去除率达74.45%。说明在12℃低温环境下,复合反应器对生活污水脱氮能力有了大幅提高。试验通过考察不同HRT、填料填充率以及温度对SND强化系统处理城市污水的影响,进一步优化SND强化工艺对寒冷地区城市污水的处理能力。当HRT为4 h、6 h、8 h时,出水NH⁺₄-N、TN浓度平均值分别为8.05 mg/L、4mg/L、2.95 mg/L,TN浓度平均值分别为16.29 mg/L、13.25 mg/L、11.01 mg/L;填料填充率为50%、40%、30%时,出水NH₄⁺-N、TN浓度平均值分别为4 mg/L、2.94 mg/L、9.05 mg/L,TN浓度平均值分别为13.25 mg/L、11.03 mg/L、16.17mg/L;温度为12℃、8℃时,出水NH₄⁺-N浓度平均值分别为2.94 mg/L、19.18mg/L,TN浓度平均值分别为11.04 mg/L、21.43 mg/L。通过SBBR反应系统处理实际生活污水,分析进、出水NH₄⁺-N、TN、COD浓度变化及去除率。第一阶段先以50%模拟污水和50%实际生活污水混合作为进水,逐步提高系统对实际生活污水水直接的适应能力,氨氮、总氮去除率分别降低至67.91%、60.02%。通过渐进的方式提高反应系统内溶解氧含量使出水NH₄⁺-N、TN浓度分别达到89.14%、73.79%。第二阶段则直接以实际生活污水作为反应器进水,NH₄⁺-N、TN去除率逐渐降低至63.28%、58.49%。通过不断调节排水,NH₄⁺-N最终去除率达89%,TN平均去除率也可达74.45%。进水COD在350mg/L⁴10mg/L波动,出水COD始终保持在50mg/L以下。利用微生物测序技术对已在12℃低温环境下驯化20天和110天的生物膜进行检测并在细菌多样性、门、纲、属水平分析生物膜菌群特性,发现驯化110天后的样品,生物膜上与脱氮相关的功能菌群活性依然较好。更多还原

【Abstract】 Urban sewage in cold areas is difficult to denitrify,and the traditional biological treatment process is difficult to operate steadily for a long time.Simultaneous nitrification and denitrification(SND)can produce nitrification,denitrification and carbon removal simultaneously in the same reactor,which fully proves the hypothesis that nitrification and denitrification can occur in the same environment,and is economical and environmentally friendly.However,in the low temperature environment,the microbial activity declined sharply,which made the effluent of the system unstable.Using biofilm filler can effectively enhance the capacity of the reaction system to treat urban sewage in cold areas.In order to achieve the standard treatment of urban sewage at low temperature,polyurethane biofilm filler was added to SBR reactor to construct a composite system of polyurethane biofilm filler and activated sludge.By analyzing the treatment effect of mature polyurethane biofilm filler and polyethylene biofilm filler on water distribution,the final filler used in the biofilm filler-activated sludge composite process(SBBR)was determined.Compared with polyethylene biofilm filler,polyurethane biofilm filler has larger specific surface area,and biofilm is easier to adhere to and grow on it.When it enters the reactor,it can quickly adhere to biofilm.The results showed that the effluent NH4~+-N and COD of the sewage treatment system with polyurethane biofilm filler were significantly higher than those of the sewage treatment system with polyethylene biofilm filler,and the average removal rates were 14.69%and 8.2%respectively.The results show that polyurethane biofilm filler has small pore and can be used as a good barrier to shelter the bacteria that have been attached to the growth and ensure that the bacteria grow in a good environment.A packed-enhanced SND reactor with aerobic activated sludge and polyurethane biofilm fillers was established to treat municipal urban sewage in a SBR reactor placed in a refrigerator.After 110 days of incubation,the concentration of NH4~+-N in effluent was maintained at 3~5 mg/L,and the removal rate of total nitrogen was74.45%.The results show that the denitrification capacity of the composite reactor for urban sewage has been greatly improved under the low temperature environment of 12℃.By investigating the effects of different HRT,filling rate and temperature on the treatment of municipal urban sewage by SND intensification system,the treatment capacity of SND intensification process for municipal urban sewage in cold areas was further optimized.When HRT was 4 h,6 h and 8 h,the average concentration of NH4~+-N and TN in effluent was 8.05 mg/L,4 mg/L and 2.95 mg/L,respectively,and the average concentration of TN was 16.29 mg/L,13.25 mg/L and 11.01 mg/L.When filling rate was 50%,40%and 30%,the average concentration of NH4~+-N and TN in effluent was 4 mg/L,2.94 mg/L and 9.05 mg/L,respectively,and the average concentration of TN was 13.25 mg/L,11.03 mg/L and 16.17 mg/L.The average NH4~+-N concentration in effluent was 2.94 mg/L,19.18 mg/L,and the average TN concentration was 11.04 mg/L and 21.43 mg/L,respectively,when the temperature was 12℃and 8℃.The actual urban sewage was treated by SBBR reaction system.The concentration changes and removal rates of NH4~+-N,TN and COD in the influent and effluent were analyzed.In the first stage,50%simulated sewage and 50%actual urban sewage were mixed as the influent to gradually improve the system’s direct adaptability to actual urban sewage.The removal rates of ammonia nitrogen and total nitrogen were reduced to 67.91%and 60.02%respectively.The concentration of NH4~+-N and TN in effluent reached 89.14%and 73.79%respectively by increasing the dissolved oxygen content in the reaction system step by step.In the second stage,the actual urban sewage was directly used as the reactor influent,and the removal rates of NH4~+-N and TN gradually decreased to 63.28%and 58.49%.Through constant regulation of drainage,the final removal rate of NH4~+-N and the average removal rate of TN can reach 89%and 74.45%,respectively.The influent COD fluctuated from 350 mg/L to 410 mg/L,while the effluent COD remained below 50mg/L.Microbial sequencing technology was used to detect the biofilm which had been domesticated for 20 and 110 days in low temperature environment.The characteristics of biofilm flora were analyzed at the level of bacterial diversity,phylum,class and genus.It was found that after 110 days of domestication,the activity of functional bacteria related to denitrification on biofilm was still good.更多还原