植物-SBR系统温室气体排放特征与减排效益研究

发布时间：2018-04-13 19:51

本文选题：污水处理 + 植物-SBR复合系统　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：污水处理过程中排放的CH_4、N_2O和CO2等气体,是大气中温室气体的主要来源之一。植物-活性污泥复合系统是一种耦合了除污植物与活性污泥工艺的景观型污水处理工艺,具有出水水质好、景观性佳、对周边环境影响小等优点。然而,对植物-活性污泥复合系统的环境效益,尤其是温室气体的排放特征及其减排的研究非常有限。本文对植物-活性污泥复合系统的温室气体排放特征及其关键影响因素进行了研究,进而分析了复合系统的减排效益与方法,为评价复合系统的环境综合效益提供了实验基础与依据。研究了不同运行工况下植物-序批式生物反应器复合系统(V-SBR)的温室气体排放特征,并与传统序批式生物反应器(SBR)和人工湿地进行了比较。结果表明,V-SBR和SBR中CH_4和N_2O的排放通量主要集中在好氧阶段,人工湿地系统的排放通量则在中午12:00达到最大,且由进水端到出水端呈逐渐下降趋势,表明其与表面负荷的显著相关性。当在去除相同总碳当量下,人工湿地和SBR的甲烷排放量分别是V-SBR复合系统的49倍和1.3倍;当在去除相同的总氮当量下,人工湿地和SBR系统N_2O的排放量分别是V-SBR系统的21.6倍和1.16倍。考察了不同影响因素,包括进水C/N、温度、曝气量、水力停留时间(HRT)、污泥负荷、共存纳米颗粒对V-SBR系统温室气体排放的影响。结果表明,CH_4的排放通量与进水C/N呈显著正相关,而N_2O排放通量与进水C/N呈负相关。V-SBR和SBR中,CH_4和N_2O排放通量均随着运行温度的提高而增加。CH_4的排放通量受曝气量的影响不显著,而N_2O排放通量随着曝气量的增加而较少。当进水中纳米银与纳米氧化锌浓度分别高于1 mg/L与10 mg/L时,对温室气体的产生与通量开始产生影响,且随着纳米颗粒浓度的增加,其影响作用逐渐加强,原因主要是聚集于活性污泥表面的纳米颗粒增加,导致微生物的活性减弱甚至死亡。水力停留时间对CH_4的排放通量的影响不显著,而与N_2O排放通量的影响呈正相关;CH_4和N_2O排放通量都随着污泥负荷的增加而增加;N_2O排放量随AMO和HAO活性的增加而增加,原因是两者可促进反应过程中亚硝酸盐氮的产生与积累。利用PCR-DGGE、荧光定量PCR和高通量测序的方法对微生物群落结构和菌群的影响进行研究。结果表明,耦合植物后的悬浮污泥、根系污泥与传统SBR系统中悬浮污泥微生物群落结构均有较大差异,但其主导菌群均为Proteobacteria。悬浮污泥与风车草根系微生物中的AOB丰度较高;V-SBR系统悬浮污泥中NOB丰度高,同时植物根系污泥中nir S型反硝化菌和古细菌含量也较高。较高的AOB和NOB含量较高会增加N_2O的产生量,而SBR中较高nir S型反硝化菌是其N_2O产生量较少的原因之一。两个系统中古细菌的含量与甲烷的产生也有一定的相关性。结合温室气体通量结果,建立了SBR和V-SBR系统中碳氮平衡模型,对CH_4和N_2O的排放量进行了对比分析。计算结果表明,SBR和V-SBR系统CH_4的年排放量分别为2.56 kg/y和1.92 kg/y,N_2O的年排放量分别为0.049 kg/y和0.045 kg/y。与SBR系统相比,V-SBR系统CH_4和N_2O的减排量分别为0.64kg/y和0.004 kg/y。同时,V-ASP系统中还可通过调控的运行参数、影响因素和优化植物配置等方法进一步减少温室气体的排放。
[Abstract]:Sewage treatment process of CH_4, N_2O and CO2 gas, is one of the main sources of greenhouse gases in the atmosphere. The plant activated sludge system is a coupling of the landscape type sewage treatment plant and decontamination process of activated sludge process, with good water quality, landscape is good, has the advantages of little impact on the surrounding environment however, the plant activated sludge system environmental benefits, especially on emission characteristics and the reduction of greenhouse gas emission is very limited. The plant activated sludge system of greenhouse gas emissions and the key influence factors were studied and analyzed with the method of emission reduction benefits of composite system and provides experiment the foundation and basis for the comprehensive evaluation of environmental benefits. The research on composite system under different operating conditions of plant - sequencing batch reactor (V-SBR) composite system of greenhouse gas emission characteristics And, with the traditional sequencing batch reactor (SBR) and artificial wetland were compared. The results show that the emission flux of CH_4 and N_2O in V-SBR and SBR mainly concentrated in the aerobic phase, the emission flux of artificial wetland system is 12:00 in the afternoon to reach the maximum, and from the water inlet to the water outlet end decreased gradually that showed a significant correlation with the surface load. When the removal of the same total carbon equivalent, methane emissions from wetlands and SBR were 49 times and 1.3 times of the V-SBR composite system; when the total nitrogen removal under the same equivalent emissions, artificial wetland system N_2O and SBR are 21.6 times V-SBR system and 1.16 times. The influence of different factors, including water temperature, C/N, aeration rate, hydraulic retention time (HRT), sludge load, effects of coexistent nanoparticles on greenhouse gas emission of the V-SBR system. The results show that the emission flux of CH_4 and influent C/N significantly With a positive correlation, and N_2O emission flux and inlet C/N was negatively related to.V-SBR and SBR, CH_4 and N_2O fluxes increased with the temperature increased.CH_4 emission flux by aeration was not significant, while the N_2O emission flux and less with the increase of aeration rate. When the concentration of silver nanoparticles and nano Zinc Oxide the water was higher than 1 mg/L and 10 mg/L, and the flux of greenhouse gases is beginning to have an effect, and with the increasing concentration of nano particles, the effect gradually strengthened, the main reason is the nano particles in the activated sludge surface is increased, leading to microbial activity decreased and even death. The influence on the flux of CH_4 emission of water the residence time was not significant, while the influence and N_2O flux was positively correlated; CH_4 and N_2O fluxes increased with increasing sludge loading; N_2O emissions increased with increasing AMO and HAO activity and The reason is the increase, can promote the production and accumulation of nitrite nitrogen in the reaction process. By using PCR-DGGE method, fluorescence quantitative PCR and high-throughput sequencing to study the effect of microbial community structure and flora. The results show that the suspended sludge coupling plant, different root sludge and traditional SBR system in suspended sludge microorganism the community structure has, but the dominant bacteria were AOB Proteobacteria. high abundance of suspended sludge and windmill roots in microorganisms; V-SBR system suspended sludge NOB in high abundance and plant roots in sludge NIR S denitrifying bacteria and archaea was also higher. Higher AOB and higher NOB content will increase the production of N_2O the amount of SBR, and high NIR S denitrifying bacteria is one of the reasons for the amount of N_2O produced less methane. And the content of the two systems of Archaea have certain correlation with. The greenhouse gas emission results, establish the balance of carbon and nitrogen model of SBR and V-SBR, on CH_4 and N_2O emissions are compared and analyzed. The calculation results show that the annual emissions of SBR and V-SBR CH_4 are 2.56 kg/y and 1.92 kg/y respectively, the annual emissions of N_2O were 0.049 kg/y and 0.045 kg/y. and SBR compared to V-SBR emission reduction system CH_4 and N_2O were 0.64kg/y and 0.004 kg/y. at the same time, the V-ASP system can also through controlling the operation parameters, method of factors and the optimization of plant disposition effect to further reduce greenhouse gas emissions.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;X16

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