【作者】 李萍；

【导师】 张兴文；

【作者基本信息】 大连理工大学 ， 环境科学与工程， 2019， 硕士

【摘要】 屠宰废水含有高浓度的氨氮和有机物,采用一般的化学物理方法比较难去除。但其可生化性好,适合采用生物法进行处理。序批式生物膜法（SBBR）作为生物法之一,具有同步硝化反硝化脱氮的特点,不需外加碳源,节约成本的同时还能获得较高的处理效率。Fe³⁺比二价阳离子具有更高的絮凝能力,且在生物法中可促进脱氮除磷,但研究相对较少。将铁离子加入到SBBR中,可为屠宰废水的生物脱氮实际应用提供参考,具有一定的应用价值。本试验根据屠宰废水的特点配制模拟屠宰废水进行研究。在2 L SBBR中添加不同浓度的Fe³⁺离子,探究其对NH₄⁺-N、NO₂^--N、NO₃^--N、COD、粒度大小、微生物群落分布及同步硝化反硝化速率的影响。通过傅立叶红外光谱（FTIR）分析探究添加铁离子前后的特征官能团的变化情况,元素分析和X光荧光光谱分析（XRF）的结合来考察活性污泥中的元素种类及含量的变化,扫描电子显微镜及光学显微镜观察菌群的形貌及分布特征。结论如下。（1）通过探究曝气量（0.2、0.4、0.6、0.8 L/min）、曝气时间（10、12、14、16 h）及Fe³⁺浓度（0、5、10、20、30、40、50 mg/L）对脱氮的影响发现,在曝气量0.6 L/min,曝气时间14 h,Fe³⁺浓度10 mg/L的条件下,NH₄⁺-N及COD去除率分别为92%和97%,NO₃^--N和NO₂^--N的浓度分别为1 mg/L和0 mg/L。Fe³⁺浓度高于10 mg/L时会产生生物毒性,抑制微生物活性,降低处理效率。（2）从硝态氮和亚硝态氮的含量大小来看,三价铁的加入提高了硝化菌与反硝化菌的活性,增强其与异养细菌的竞争能力,减少了NO₃^--N和NO₂^--N的积累,NO₂^--N含量全程接近0。含Fe³⁺组使反应器内保留了更多生物量,保证了污染物的较高去除率。Fe³⁺的存在减少了系统中H⁺的积累,使得出水pH值保持相对稳定。（3）SEM及镜检观察发现,含Fe³⁺污泥中微生物相更丰富。含Fe³⁺体系主要含球形硝化菌,絮体颗粒更细小,减少了低氧水平下氧气的传质阻力。粒径分析表明Fe³⁺的加入有助于降低颗粒粒径分布的分散趋势,保证了反应器内颗粒污泥的均匀分布。（4）低温条件下,含Fe³⁺组和不含Fe³⁺组的E_SND分别为87.08%和78.65%,含Fe³⁺组比不含Fe³⁺组高8.43%。三价铁的加入提高了系统的抗低温负荷能力,在低温下也能获得较高的同步硝化反硝化速率。高温条件下的差距较小,含Fe³⁺组和不含Fe³⁺组的E_SND分别为99.94%和97.54%,仅相差2.4%。（5）添加三价铁后的出峰数明显增多,吸收峰强度也显著增大。多糖、蛋白质中的O—H伸缩振动,酰胺Ⅰ带、蛋白质中的C=O伸缩振动,多糖中的C—OH弯曲振动均得到增强。结果表明,蛋白质及多糖类物质的含量得到增加。更多还原

【Abstract】 Slaughter wastewater contains high concentrations of ammonia nitrogen and organic compounds,which are difficult to remove by conventional chemical and physical methods.However,it is biodegradable and suitable for biological treatment.As one of the biological methods,sequencing batch biofilm method（SBBR）has the characteristics of simultaneous nitrification and denitrification.It does not need an external carbon source,and it can save cost and obtain high processing efficiency at the same time.Fe³⁺has higher flocculation capacity than divalent cations,and can promote the removal of nitrogen and phosphorus in biological methods,but relatively few studies have been conducted on it.The addition of iron ions into SBBR can provide reference for the practical application of biological nitrogen removal in slaughter wastewater,which has certain application value.In this experiment,simulated slaughtering wastewater was prepared according to the characteristics of slaughtering wastewater.Different concentrations of Fe³⁺ions were added in 2 L SBBR to explore their influence on NH₄⁺-N,NO₃^--N,NO₂^--N,COD,particle size,microbial community distribution and simultaneous nitrification and denitrification rate.The changes of characteristic functional groups before and after the addition of iron ions were investigated though Fourier transform infrared spectroscopy（FTIR）.The combination of element analysis and X-ray fluorescence spectrum analysis（XRF）were used to investigate the changes of element types and content in activated sludge,and the morphology and distribution characteristics of the microflora were observed by scanning electron microscope and optical microscope.The conclusions are as follows.（1）By exploring the influence of aeration volume（0.2,0.4,0.6,0.8 L/min）,aeration time（10,12,14,16 h）and concentration of Fe³⁺（0,5,10,20,30,40,50 mg/L）on nitrogen removal.It was found that,under the conditions of aeration volume of 0.6 L/min,the aeration time of 14 h,the Fe³⁺concentration of 10 mg/L,the removal rates of NH₄⁺-N and COD were92%and 97%respectively,and the concentrations of NO₃^--N and NO₂^--N were 1 mg/L and 0mg/L respectively.When the concentration of Fe³⁺is higher than 10 mg/L,it will produce biological toxicity,inhibit microbial activity and reduce the efficiency of treatment.（2）From the content of nitrate nitrogen and nitrite nitrogen,the addition of ferric iron increased the activity of nitrifying and denitrifying bacteria,enhanced their competitiveness with heterotrophic bacteria,and reduced the accumulation of NO₃^--N and the content of NO₂^--N was close to 0.The group containing Fe³⁺retained more biomass in the reactor and ensured a higher removal rate of pollutants.The addition of Fe³⁺reduced the accumulation of H⁺in the system and kept the effluent of pH relatively stable.（3）SEM and microscopic observation showed that the microbial phase in sludge containing Fe³⁺was more abundant.The system containing Fe³⁺mainly contained spherical nitrifying bacteria with finer floc particles,which reduced the mass transfer resistance of oxygen at low oxygen level.Particle size analysis showed that the addition of Fe³⁺reduced the dispersion trend of particle size distribution and ensured the uniform distribution of granular sludge in the reactor.（4）At low temperature,the E_SND of the group with and without Fe³⁺were 87.08%and78.65%respectively,and E_SND of the group with Fe³⁺was 8.43%higher than that of the group without Fe³⁺.The addition of ferric iron improved the resistance of system to low temperature loads and can obtained higher simultaneous nitrification and denitrification rate at low temperature.At high temperature,and the E_SND of the group with and without Fe³⁺were99.94%and 97.54%respectively,and the difference was only 2.4%.（5）After adding ferric iron,the number of peak and intensity of the absorption peak increased significantly.O-H stretching vibration of polysaccharide and protein,C=O stretching vibration of amide I band and the protein,and C-OH bending vibration of polysaccharide were enhanced.The results showed that the content of protein and polysaccharide were increased.更多还原